Starch Selection in Sweet Food Systems: A Texture‐Driven Framework Across Confectionery and Dessert Matrices

ABSTRACT

Sweet food systems present a uniquely complex environment for starch functionality across confections, baked goods, dairy desserts, fruit‐based products, and bakery fillings. The role of starch varies fundamentally between product categories; therefore, its selection and application cannot be treated as generic. The sugar‐dominated matrices of these products alter starch gelatinization temperature, retrogradation tendency, and water distribution in ways that vary with sweetener identity, concentration, and molecular structure; however, real sweet food systems are inherently multicomponent, making starch behavior in these matrices substantially more complex than model‐system predictions suggest. This review provides an integrated starch selection framework for sweet food formulation, analyzing functionality and modification requirements across seven major product categories: caramel and toffee, gummies and jelly candy, hard candy, cookies and biscuits, bakery fillings, jams and fruit preserves, and custards and dairy desserts. The central principle is that starch selection must be matched to the dominant failure mode of the specific matrix because no single starch type or modification approach addresses the full range of functional requirements across sweet food systems. The sugar‐starch interaction is established as the mechanistic foundation for product‐specific selection, with particular attention to how reformulation pressures, including sugar reduction, fat reduction, and clean‐label demands, alter this interaction in ways that make conventional reference data unreliable. Recommendations are explicitly characterized as directly evidenced by product‐specific studies or analytically synthesized where direct evidence is absent, transparently identifying where experimental validation remains needed. Three cross‐cutting formulation challenges are critically examined: the clean‐label paradox, starch‐flavor binding, and the limitations of predictive models in multi‐ingredient sweet food matrices.

Starch functions as a key hydrocolloid shaping texture and stability in the formulation engineering of sweet foods. Sugar‐starch hydration interactions control gelatinization and rheological behavior. Modified starches enhance tolerance to heat, shear, acidity, and low moisture, and starch‐hydrocolloid blends enable tailored textures and improved shelf life.

1. Introduction

Sweet food products constitute a complex, globally significant segment of the food supply, encompassing confections including sweets, candies, and chocolate, sweet bakery products such as pastries, cakes, and cookies, dairy‐based and non‐dairy desserts, fruit‐based spreads and preserves, and bakery filling formats including fruit fillings, chocolate fillings, and honey‐based fillings (McKenzie and Lee ²⁰²²; Vepsäläinen and Sonestedt ²⁰²⁴). What unites these products across their structural diversity is the functional primacy of sugar in their matrices: sucrose, glucose, fructose, and their derived syrups govern water distribution, phase behavior, glass transition, thermal reactivity, and osmotic stability simultaneously, making sugar a primary engineering variable rather than merely a sensory agent (Pittia and Antonello 2016; Wang et al. ²⁰²⁵). Every other structural ingredient, including starch, must therefore perform its intended function within a sugar‐dominated matrix that competes for water, modulates thermal transitions, and imposes product‐specific processing and storage demands.

Starch is present across virtually all sweet food categories yet performs fundamentally different functional roles depending on the matrix: it acts as a primary heat‐activated gel former in custards and starch‐based jelly candies, a dispersed particulate phase providing body and yield stress in caramel, a network reinforcer within pectin‐based jams, and a largely inactive structural filler in cookies where its primary requirement is controlled inactivity to preserve dough flow. This divergence is compounded by the effect of sugar on starch behavior at the molecular level: sugars bind water and reduce free water availability for starch granule hydration, directly elevating gelatinization temperature and reducing gelatinization efficiency (Allan et al. 2018; Renzetti et al. ²⁰²¹), while retrogradation tendency is further modulated by sweetener identity, molecular structure, and concentration in ways that cannot be predicted from simple water competition alone (Allan and Mauer 2022; Woodbury et al. ²⁰²³). The result is that starch selection in sweet food formulation is a matrix‐specific engineering problem: the type of modification, botanical source, and concentration appropriate for one product may be structurally counterproductive or entirely unnecessary in another.

Despite this complexity, the existing literature does not provide an integrated framework for starch selection across the sweet food spectrum. Published reviews address starch modification chemistry broadly (Chakraborty et al. 2022), starch gel behavior under controlled model conditions (Gong et al. 2024), or specific modification strategies such as cross‐linked starches across food applications (Punia Bangar et al. 2024) in isolation; none systematically examines starch functionality across the full range of sweet food matrices through the lens of the sugar‐starch interaction as the organizing principle for product‐specific selection. Four specific gaps follow from this absence: the cross‐category divergence in starch's functional role has not been mapped through a unified analytical framework; the sugar‐starch interaction, while studied in binary and model systems, has not been translated into practical product‐specific starch selection guidance; the distinction between directly evidenced starch recommendations and those derived by analytical inference from general modification principles has not been made explicit, a critical omission when the same starch strategy cannot be assumed to transfer across products with fundamentally different matrix conditions; and the reformulation challenges arising from sugar reduction (McKenzie and Lee ²⁰²²) and clean‐label demands (Bogdanoff et al. 2025), each of which alters the sugar‐starch interaction in ways that make conventional reference data unreliable, have not been addressed systematically across sweet food categories.

This review addresses these gaps by providing a product‐by‐product analytical framework for starch functionality and selection across seven major sweet food categories: caramel and toffee, gummies and jelly candies, hard candies, cookies and biscuits, bakery fillings including fruit, chocolate, and honey‐based formats, jams and fruit preserves, and custards and dairy desserts including puddings and mousses. The organizing principle advanced throughout is therefore product‐specific: starch selection must target the dominant failure mode of the matrix it will operate in, because functional requirements diverge so substantially across sweet food categories that no single starch type or modification strategy can address them universally. The review proceeds by establishing the physicochemical roles of sugar in sweet food matrices, the principles of formulation engineering in sugar‐rich systems, and the mechanisms by which sugar modulates starch gelatinization, retrogradation, and matrix behavior, before examining modification strategies for sweet‐food‐specific starch challenges and conducting product‐specific analysis across all seven categories. A critical examination of three cross‐cutting challenges (the clean‐label paradox, starch‐flavor binding, and predictive modeling limitations) follows, with research priorities identified in the final section. Throughout, the basis for each starch recommendation is made explicit: where product‐specific experimental evidence exists, it is cited directly; where it does not, the recommendation is identified as an analytical synthesis based on general modification principles, thereby flagging the need for experimental validation.

2. Sugars in Sweet Food Formulations: Functions, Mechanisms, and Limitations

Sugars function in sweet food matrices not merely as sensory agents but as primary structural and physicochemical components of the food matrix. Sucrose, glucose, fructose, lactose, and their derived syrups, individually and in combination, fulfill six distinct roles across these product categories: they provide sweetness; they bind and redistribute water and influence water mobility; they control physical structure by modulating gelation and emulsion stability, determining the load‐bearing network in gelled and emulsified product formats; they govern the thermal behavior of the matrix, directly determining glass transition temperature, crystallization and melting tendency, and amorphous‐state stability, while concurrently modulating starch gelatinization, protein gelation, and hydrocolloid network setting through competitive binding of available water; they drive the non‐enzymatic browning reactions responsible for color and flavor development; and they suppress microbial and enzymatic activity through osmotic reduction of water availability (Clemens et al. 2016; Goldfein and Slavin ²⁰¹⁵; Pittia and Antonello ²⁰¹⁶). These contributions are not interchangeable. Each reflects a mechanistically distinct interaction between sugar molecules, water, and the broader food matrix and understanding them at this mechanistic level is a prerequisite for predicting where sugar functionality fails and where complementary ingredients such as starch become structurally necessary.

The functional versatility of sugars can be organized around four principal physicochemical mechanisms, which collectively underlie the six functional roles identified above.

2.1. Hydration and Water Binding

Sugar–water interactions are highly structure‐dependent and cannot be explained by hydroxyl group count alone. Terahertz spectroscopic studies have demonstrated that glucose, fructose, sucrose, and trehalose differ markedly in hydration capacity because the stereochemical orientation of hydroxyl groups, equatorial versus axial, determines both the strength and lifetime of sugar–water hydrogen bonds (Penkov 2021; Shiraga et al. ²⁰¹⁵). At the high solids concentrations characteristic of sweet food manufacturing, hydration shells of adjacent sugar molecules progressively overlap, reducing the fraction of bulk‐like, freely mobile water in the system. The degree to which sugars restrict water mobility in a food matrix is therefore jointly determined by the number of hydroxyl groups, their stereochemical orientation, and total sugar concentration. In product terms, this collective influence shapes water activity and shelf stability in jams and confections, controls viscosity and flow behavior in caramel and custard systems, and governs moisture retention and hygroscopic behavior in low‐moisture sweet baked products and hard candy. At the level of starch processing, the same restriction of water availability delays granule swelling, elevates gelatinization onset temperature, and modulates the rate and extent of network formation during cooling.

2.2. Phase Behavior and Glass Transition

In concentrated sweet food systems, sugars do not behave as simple solutes but exist across a thermodynamic continuum of physical states, dissolved, supersaturated, amorphous, glassy, and crystalline, and the macroscopic texture of a product is largely governed by which state prevails and how stable it is under processing and storage conditions (McGill and Hartel ²⁰²⁰). Amorphous sugar matrices are kinetically metastable below their glass transition temperature (Tg); crossing Tg, whether through temperature increase or through moisture‐driven plasticization that depresses Tg toward ambient conditions, raises molecular mobility to the point where crystallization, stickiness, or matrix collapse becomes kinetically accessible (McGill and Hartel ²⁰²⁰; Feng et al. ²⁰²²). These transitions underlie common quality defects: graining in fondants and caramels, sugar bloom in coated confections, and loss of brittleness or crispness in hard candy and biscuit systems, with onset sensitive to small deviations in formulation or storage humidity (Feng et al. 2022).

2.3. Thermal Reactivity

Two non‐enzymatic browning pathways define the thermal chemistry of sugar‐rich systems and cannot be treated as equivalent. The Maillard reaction proceeds between the free carbonyl groups of reducing sugars and the nucleophilic amine groups of amino acids or proteins, generating melanoidins alongside a structurally diverse spectrum of volatile aroma compounds; its rate and product profile depend critically on temperature, reaction time, water activity, pH, and the specific reducing sugar and amino acid species present (El Hosry et al. 2025; Manzocco et al. ²⁰⁰⁰). Caramelization, by contrast, requires no nitrogenous co‐reactant and proceeds through the direct thermal dehydration and pyrolytic rearrangement of sugar molecules; onset temperature is strongly species‐dependent, occurring at approximately 110°C for fructose and 160°C for glucose, which means that formulations differing only in sugar composition can show substantially different browning behavior under identical processing conditions (Clemens et al. 2016). That both reactions are modulated by overlapping formulation variables: water activity, temperature, and pH, means their relative contribution to product color and flavor is rarely fixed and is often difficult to attribute unambiguously in complex food matrices.

2.4. Osmotic Effects and Water Activity Reduction

Dissolved at high concentrations, sugars generate substantial osmotic pressure in the aqueous phase, reducing water activity (aw) below the thresholds required for microbial proliferation and many enzymatic spoilage pathways (Pittia and Antonello 2016). The magnitude of aw depression also depends on sugar type and concentration; at equivalent mass concentrations, lower‐molecular‐weight sugars such as glucose and fructose generally exert greater colligative effects than sucrose, while also differing in hydration behavior, reactivity, and crystallization tendency (Pittia and Antonello 2016). This relationship does not extend uniformly to chemical reactions, however: non‐enzymatic browning, particularly the Maillard reaction, is often favored at intermediate aw values, with faster kinetics reported around aw 0.6–0.7 or broadly within the 0.5–0.8 range (El Hosry et al. 2025). Taken together, these relationships establish aw as a necessary but insufficient descriptor of stability in sweet food systems, underscoring the need to consider it alongside complementary parameters such as glass transition temperature and molecular mobility.

Despite this mechanistic breadth, sugars alone are insufficient to meet the full range of structural and stability demands encountered in sweet food manufacturing, and these insufficiencies motivate the central argument of this review. The most consequential limitation is structural: sugars are not network‐forming biopolymers and cannot independently generate the viscoelastic gel matrix required for mechanical integrity in semi‐solid and gelled product categories. In systems such as jams and fruit preparations, the load‐bearing structure is formed by pectin, with sugar controlling water availability, soluble solids concentration, and the ionic environment necessary for gel setting, rather than providing the network itself (Goldfein and Slavin 2015). Similarly, in starch‐containing systems including custards, fillings, and confections, structural integrity depends on polysaccharide and starch granules acting as scaffold and filler components, while mono‐ and disaccharides modulate texture and hygroscopicity without substituting for that structural role (Feng et al. 2022). Where crystallization does provide structure, as in fondant, fudge, or crystalline confections, the process is inherently sensitive to perturbation; deviations in temperature, seeding conditions, or moisture content are sufficient to shift the system toward undesired polymorphic forms or uncontrolled crystal growth, compromising both texture and shelf life in ways that are difficult to correct post‐manufacture (McGill and Hartel ²⁰²⁰; Ozel et al. ²⁰²⁴). Under the acidic conditions characteristic of fruit‐based systems, sucrose undergoes acid‐ and heat‐catalyzed hydrolysis to equimolar glucose and fructose, disrupting crystallization kinetics by introducing competing solutes that reduce sucrose solubility and alter supersaturation dynamics (McGill and Hartel ²⁰²⁰; Ozel et al. ²⁰²⁴). In low‐moisture sweet baked goods such as biscuits and cookies, sugar type and concentration govern structural development through their effects on dough rheology, starch gelatinization, and moisture distribution during baking, yet these same interactions leave the final matrix structurally dependent on the sugar phase remaining stable during storage (Clemens et al. 2016; Renzetti and van der Sman ²⁰²²). The amorphous glassy state that underpins crispness and dimensional stability in these products is susceptible to water plasticization, a depression of the glass transition temperature that, when crossed, increases molecular mobility and drives moisture migration, surface stickiness, or textural softening depending on the direction and magnitude of the shift (McGill and Hartel ²⁰²⁰; Ozel et al. ²⁰²⁴). Collectively, these limitations define a structural gap: sugars are indispensable as molecular modulators of water, phase, and reactivity, but they cannot, without additional matrix support, maintain the textural integrity, gelation properties, or moisture stability that characterize high‐quality sweet food products, a gap that starch, through its gelatinization capacity, gel‐network formation, and controlled retrogradation behavior, is specifically positioned to address.

3. Formulation Engineering in Sweet Food Systems

Formulation engineering is an applied discipline that integrates materials science, rheology, and process design to translate a defined set of ingredients into a food product with targeted functional and sensory properties (Wilms et al. 2021). Unlike empirical product development, which iterates primarily on sensory outcomes, formulation engineering interrogates the physical behavior of the food matrix at each stage of manufacturing, mixing, thermal treatment, deposition, and storage. Its central premise is that ingredient selection must be guided not only by desired final product attributes but by the matrix behavior required under specific industrial processing conditions.

In sweet food systems, this engineering perspective is particularly critical because these products span an unusually diverse range of structural forms, from viscoelastic gels and colloidal emulsions to amorphous glasses and crystalline confections (Pawde and Dave 2025). Each format imposes distinct physicochemical demands on formulation components, including starch. As a result, sweet food design is not reducible to single‐ingredient optimization; it requires a systems‐level view that accounts for competitive interactions among sugars, starches, fats, and water.

Three principal processing challenges define the formulation engineering requirements for starch in sweet foods. First, mechanical operations such as high‐pressure homogenization, continuous pumping, and industrial mixing subject starch granules to intense shear stress (Ahuja et al. 2020; Fu et al. ²⁰¹¹). The starch‐containing dispersion must exhibit shear‐thinning behavior to facilitate flow, while granule integrity must be preserved to deliver viscosity and structure in the final product, as granule rupture releases starch polymer uncontrollably, producing erratic rather than stable viscosity development (Ahuja et al. 2020). Second, thermal processing imposes a gelatinization control challenge. In dairy‐based systems processed by UHT or HTST pasteurization, premature granule swelling fouls heat exchanger surfaces, compromising process efficiency and product consistency (Ayadi et al. 2005; Plana‐Fattori et al. ²⁰¹⁶). The process window, the temperature interval within which starch must resist swelling before completing gelatinization downstream, is tightly defined and starch‐source‐dependent (Pérez‐Santos et al. ²⁰¹⁶). Third, in low‐moisture baked goods such as cookies, the engineering challenge shifts from flow management to thermodynamic phase control. Here, starch acts as a structural filler or moisture modulator, influencing Tg and water mobility to maintain the matrix structure required for desired texture and shelf‐life stability (Roze et al. 2023; Wang et al. ²⁰²¹).

Mechanical resilience, thermal process control, and phase‐state management are not static design parameters but active, evolving challenges specific to each product category. The structural diversity of sweet food formats, combined with the multifunctional role of sugar in each matrix, means that no single formulation solution transfers reliably across product categories or processing environments. This inherent complexity is precisely why a rigorous, science‐driven approach to starch‐function matching remains indispensable in sweet food design.

4. Starch–Sugar Interactions in Sweet Food Systems

Starch functionality in sweet food systems is fundamentally shaped by the sugar matrix surrounding it, and because that matrix varies substantially across product categories in its composition, concentration, and processing history, starch behavior cannot be understood or predicted from water‐based systems alone. Three coupled mechanisms govern this relationship: first, competitive hydration and direct sugar–starch hydrogen‐bonding interactions in the amorphous granule regions jointly delay gelatinization onset, constrain granule swelling, and limit viscosity development, with the magnitude of these effects determined by both sugar concentration and molecular identity (Allan et al. 2018; Renzetti et al. ²⁰²¹); second, sugars modulate post‐gelatinization polymer reassociation in a concentration‐ and identity‐dependent manner, either inhibiting or promoting retrogradation depending on the sweetener composition and the soluble solids level of the system (Allan and Mauer 2022; Woodbury et al. ²⁰²³); and third, thermally or acid‐driven starch hydrolysis releases reducing sugars that may contribute to non‐enzymatic browning, introducing a starch‐derived variable in color and flavor development (Chen et al. 2017; Woo et al. ²⁰¹⁵). These mechanisms are not independent; they overlap across processing stages and product categories, and their combined effect determines texture, stability, and sensory outcome. This section examines each mechanism in sequence, with explicit attention to product‐specific implications and the formulation responses they demand. The three mechanisms governing starch–sugar interactions in sweet food systems are summarized in Figure 1. The competitive hydration dynamics underpinning starch gelatinization and retrogradation in sugar systems are conceptually summarized in Figure 2.

FIGURE 1.

Mechanistic pathways by which sugars regulate starch gelatinization, retrogradation, and non‐enzymatic browning in sweet food systems.

FIGURE 2.

Starch–sugar competitive hydration and its effects on gelatinization and retrogradation.

4.1. Competitive Hydration and Its Consequences for Starch Gelatinization

In sweet food systems, the sugar matrix systematically delays and weakens starch gelatinization, and because the magnitude of this effect is determined by both the concentration and the molecular identity of the sugars present, no single thermal processing condition or starch choice is universally appropriate across product categories.

Dissolved sugars raise the gelatinization temperature of starch through two interrelated mechanisms: they reduce free water availability for granule hydration by competing for water molecules through hydrogen bonding, and they form direct stabilizing interactions with starch molecules in the amorphous regions of the granule, requiring greater thermal energy to disrupt granule structure (Allan et al. 2018). Renzetti et al. (2021) formalized this framework using the effective volumetric density of hydrogen bonds in solution (Φw, eff), demonstrating that gelatinization temperature across a wide range of sugars and sugar replacers can be predicted from this parameter: as sugar concentration increases, Φw, eff decreases, and gelatinization temperature rises correspondingly. The complementary volumetric hydroxyl density parameter (NOH, s/vs) further captures how individual sugar species differ in their capacity to interact with starch chains, with lower values indicating less effective plasticization and higher gelatinization temperatures (Renzetti et al. 2021).

These effects are strongly concentration dependent. Allan et al. (2018), using DSC across 19 sugars and sugar alcohols in wheat starch, found that all sweeteners significantly increased the onset gelatinization temperature relative to the water control (~60.8°C), with shifts growing as a quadratic function of concentration. Woodbury et al. (2023) confirmed this pattern across food‐relevant concentrations: at 30% w/w sucrose, the gelatinization onset increased from approximately 61°C–72°C, a shift of roughly 11°C, while at 60% sucrose the onset approached 99°C.

Beyond concentration, sugar molecular identity independently determines the extent of gelatinization temperature elevation. At equivalent w/w concentrations, sucrose consistently elevated the gelatinization temperature more than the monosaccharides glucose and fructose: at 30% w/w, sucrose raised the Tgel by approximately 11.5°C compared to approximately 8.5°C for glucose and 7.6°C for fructose (Woodbury et al. 2023). Allan et al. (2018) further demonstrated that on a percent‐solids basis, 12‐carbon disaccharides generally raised the gelatinization temperature more than 6‐carbon monosaccharides, with 5‐carbon sugars producing the smallest shifts. This distinction extends within the monosaccharides themselves: at 45% w/w, glucose elevated the onset Tgel to approximately 77.5°C compared to 76.0°C for fructose, a difference that becomes more pronounced at higher concentrations, indicating that even between closely related sugars, molecular identity is a meaningful variable in gelatinization behavior (Allan et al. 2018; Woodbury et al. ²⁰²³). The underlying basis is the capacity of the sugar to form stabilizing intermolecular hydrogen bonds with starch in the amorphous regions: sweeteners with a greater number of equatorial and exocyclic hydroxyl groups show a strong positive correlation (R² = 0.88) with gelatinization temperature elevation, as these more reactive groups form preferential interactions with starch chains (Allan et al. 2018). Sucrose, with its higher molecular weight and greater number of effective hydroxyl groups per molecule (NOH, s), exhibits both greater solution viscosity and lower volumetric hydrogen‐bond density (NOH, s/vs. = 20.3) than glucose (34.2) or fructose (30.8) at equal mass concentrations (Renzetti et al. 2021); the lower this parameter, the less effective the sugar‐water mixture is as a plasticizing solvent for starch, which directly raises the gelatinization temperature (Renzetti et al. 2021; Woodbury et al. ²⁰²³). This sugar‐type ranking has been confirmed across multiple starch botanical origins including wheat, potato, and corn (Allan et al. 2020) and rice and tapioca starches (Boonkor et al. 2022), indicating that the hierarchy reflects sugar chemistry rather than starch source. Li et al. (2024) further demonstrated that starch fine molecular structure, specifically the chain‐length distribution of amylopectin short‐chain fractions, modulates the sensitivity of gelatinization parameters to sugar type, meaning that botanical origin and modification strategy interact with sugar composition in setting the processing window. Starch must therefore be selected and, where necessary, modified with reference to the specific sugar matrix it will encounter, not in isolation.

4.2. Sugar‐Mediated Modulation of Starch Retrogradation and Storage Texture

In sweet food systems, sugar effects on starch retrogradation are neither uniformly inhibitory nor uniformly promotional; they are concentration‐dependent, and at the high sugar concentrations characteristic of most sweet food matrices, the direction of the effect is determined primarily by sugar molecular structure rather than concentration alone.

Starch retrogradation proceeds in two temporally distinct stages: rapid amylose reassociation within hours to days of cooling, and slower amylopectin recrystallization over weeks of storage (L. Zhang et al. ²⁰²⁴). Both stages are influenced by sugars, but the nature of that influence varies systematically with concentration. Allan and Mauer (2022), comparing 20 sweeteners across concentrations from 10% to 50% w/w in wheat starch gels, identified three broad categories of sweetener behavior: consistent retrogradation promoters across all concentrations, consistent inhibitors, and, critically, a large group that inhibited retrogradation at low concentrations (10%–20%) but promoted it at higher concentrations (≥ 30%–40%). This concentration‐dependence reflects a mechanistic shift: at low sweetener concentrations, sugar molecules interfere with crystallization nucleation by occupying potential starch–starch junction sites; at high concentrations, the same intermolecular interactions bridge starch chains and facilitate polymer reassociation, ultimately accelerating recrystallization (Allan and Mauer 2022).

At the sugar concentrations that define sweet food products, typically 30%–65% soluble solids, sugar identity becomes the primary determinant of retrogradation behavior. Woodbury et al. (2023), using DSC and oscillatory rheometry across 0%–60% w/w sugar concentrations, demonstrated that at 30%–60% w/w, fructose and a 50:50 glucose–fructose mixture consistently promoted amylopectin retrogradation compared to the water control, with DSC enthalpies increasing progressively as fructose concentration increased. Under the same conditions, sucrose and glucose inhibited amylopectin recrystallization. The promotional effect of fructose at high concentrations has been attributed to its disruption of the tetrahedral hydrogen‐bonding network of water, thereby increasing the effective local concentration of amylopectin chains and accelerating their reassociation (Woodbury et al. 2023). Sucrose was the most consistent inhibitor of retrogradation across the range studied, attributed to its higher number of equatorial hydroxyl groups, which stabilize the water structure surrounding starch chains and constrain the molecular mobility needed for chain‐chain approach and recrystallization (Allan and Mauer 2022; Woodbury et al. ²⁰²³). Sugar alcohols such as sorbitol and xylitol, owing to their flexible open‐chain structures and extensive hydrogen‐bonding capacity, were the most consistent retrogradation promoters regardless of concentration, as their molecular geometry facilitates bridging interactions between adjacent starch polymer chains (Allan and Mauer 2022).

Consistent promoters across all concentrations included sugar alcohols such as xylitol and sorbitol, while consistent inhibitors such as allulose and tagatose were also associated with the smallest gelatinization temperature elevations, suggesting that weaker starch interactions underlie both behaviors and point to a unified mechanistic basis linking gelatinization and retrogradation responses to sugar molecular structure (Allan and Mauer 2022). Sucrose, glucose, fructose, and maltitol all showed concentration‐dependent behavior, inhibiting retrogradation at low concentrations and shifting toward promotion as concentrations increased (Allan and Mauer 2022). When hydrocolloids are also present, as is common across puddings, mousses, and bakery fillings, their independent effects on water distribution and chain mobility interact with these sugar‐driven dynamics and can moderate or amplify retrogradation outcomes (Tunnarut and Pongsawatmanit 2017), reinforcing that starch behavior in real formulations is rarely governed by a single ingredient. Because the direction and magnitude of sugar effects on retrogradation depend jointly on sugar identity and concentration, and because sweet food matrices typically operate in the high‐concentration range where these effects are most differentiated, starch selection for any sweet food system must account for the full sweetener composition of the matrix, not simply its total soluble solids content.

4.3. Starch Hydrolysis as a Secondary Contributor to Non‐Enzymatic Browning in Sweet Food Systems

Thermal or acid‐induced starch hydrolysis can generate reducing sugars that contribute to non‐enzymatic browning in sweet food systems, making starch hydrolytic susceptibility a secondary but formulation‐relevant variable in controlling color intensity and flavor development, particularly in baked products where temperature and moisture gradients amplify local reactivity.

Under the elevated temperatures and, in many cases, low pH conditions of sweet food processing, thermal or acid catalysis cleaves glycosidic bonds within starch chains, both α‐(1 → 4) and α‐(1 → 6) linkages, liberating reducing sugars, primarily glucose and maltose, into the local reaction environment (Chen et al. 2017; Wang and Copeland ²⁰¹⁵). Once liberated, these sugars can participate in both the Maillard reaction and caramelization simultaneously, with browning onset typically occurring above approximately 105°C–120°C as local water activity falls below 0.4–0.7 at the product surface (Purlis 2010). The extent of starch‐derived sugar generation depends on processing temperature, moisture content, pH, and the intrinsic hydrolytic susceptibility of the starch, which is in turn governed by granular architecture, amylose content, and degree of crystallinity (Chen et al. 2017; Wang and Copeland ²⁰¹⁵).

In baked sweet foods such as cookies and biscuits, this process contributes to measurable spatial heterogeneity in browning. Chen et al. (2024) demonstrated, using spatially resolved monitoring of moisture content, water activity, surface temperature, and color indexes at multiple locations within cookies baked at 185°C–225°C, that ring and edge regions dried faster and reached higher local temperatures, with differences of 7°C–18°C relative to core regions. These hotter, drier regions developed more pronounced browning, reflected in lower lightness values and elevated browning index, while core regions retained higher residual moisture and showed substantially slower color development. These gradients reflect the spatial variation in temperature and water activity that governs the local intensity of non‐enzymatic browning reactions across the product, and the degree to which starch‐derived reducing sugars contribute to browning at any given location will accordingly depend on the local thermal and hydration environment.

Starch modification affects this pathway in ways that are seldom addressed explicitly in formulation practice. Hydrolytic susceptibility is strongly determined by granular structure: amorphous regions are preferentially attacked, and starches with higher crystallinity or more compact amorphous domains, such as high‐amylose varieties, show substantially lower susceptibility to both acid and thermal hydrolysis than waxy or low‐amylose counterparts, thereby limiting their contribution to the pool of reactive reducing sugar intermediates (Chen et al. 2017; Wang and Copeland ²⁰¹⁵). This suggests that in low‐reducing‐sugar formulations or acidic product matrices, starch‐derived reducing sugars may become proportionally more relevant to browning outcomes, particularly under high‐temperature or prolonged processing conditions. Proteins competing with starch for available water under dry‐heat conditions can further amplify local Maillard reactivity by reducing gelatinization extent and concentrating reactive intermediates at the product surface (Li et al. 2023); lipids alter thermal conductivity and phase behavior, shifting the spatial onset and distribution of browning reactions (S. Wang et al. ²⁰²⁰). Managing color development in sweet baked and confected systems therefore benefits from considering starch hydrolytic resistance alongside the conventional focus on added sugar chemistry.

5. Applications of Starch in Sweet Food Products

The mechanistic relationships established in Section 4, competitive hydration, retrogradation modulation, and starch‐derived contributions to non‐enzymatic browning, define how starch behaves within a sugar‐rich matrix, but they do not in themselves determine which starch is appropriate for a given product. That determination requires translating matrix conditions into functional requirements: what moisture content, sugar concentration, pH, and processing intensity does the product impose on starch, and what must starch deliver in terms of viscosity, gel strength, water retention, or structural stability to meet product quality specifications? These conditions vary substantially across sweet food categories, and the subsections that follow are organized accordingly, products sharing similar matrix physicochemistry and, consequently, similar starch functional demands are examined together. This organization is reflected schematically in Figure 3, which illustrates how starch microstructural state across diverse product matrices is governed by the moisture level, sugar concentration, and thermal history of the surrounding matrix rather than by starch source or modification alone.

FIGURE 3.

Starch microstructural state and governing matrix conditions across five representative sweet food product categories.

Because native starches are insufficient under the acid, shear, thermal, or storage stresses that characterize most sweet food categories, modified starches are the primary formulation tool throughout this section; the exceptions are low‐moisture baked systems, where controlling native starch damage is the relevant strategy, and hard candy, where intact granular starch has no formulation role. Modification strategies can be broadly distinguished by the type of functional limitation they address. Structural reinforcement through cross‐linking introduces covalent phosphate or adipate bridges between polymer chains, increasing granule resistance to breakdown under heat, shear, and acidic conditions (Punia Bangar et al. 2024). Substitution strategies, hydroxypropylation and acetylation, introduce bulky side groups that sterically disrupt chain‐chain hydrogen bonding, suppressing retrogradation and reducing syneresis; acetylation additionally promotes the formation of soft, clear gel structures during cold or extended storage (Fu et al. 2019; Subroto et al. ²⁰²³). Dual modification combines structural reinforcement with substitution to address both processing stability and storage performance simultaneously, in systems where neither strategy alone is sufficient (Lagunes‐Delgado et al. ²⁰²⁴). Beyond chemical modification, pregelatinized starches develop viscosity without applied heat by virtue of their pre‐cooked, dried granular structure (Lee and Yoo 2023), while physically modified starches, prepared through heat‐moisture treatment or annealing without chemical reagents, offer moderate improvements in paste stability and retrogradation resistance, providing a clean‐label pathway where chemical modification is undesirable (Fonseca et al. 2021). The structural basis, functional advantage, and key references for each of these modification strategies are summarized in Table 1. The specific strategy appropriate to each product category, and the reasoning that connects matrix conditions to that selection, is the subject of the subsections that follow and is summarized in Table 2.

TABLE 1.

Starch modification strategies: Structural basis, functional advantage, and key references.

Starch strategy	Main structural or molecular effect	Functional advantage	Key references
Cross‐linking (phosphate or adipate bridges)	Covalent bonds between adjacent starch chains restrict granule swelling and resist dispersal under heat, acid, and shear	Maintains viscosity and granule integrity under high‐temperature and acidic processing; prevents shear‐induced thinning	Punia Bangar et al. (2024); Shah et al. (2016); Tan et al. (2014)
Hydroxypropylation (E1440; E1442 in combination)	Bulky hydroxypropyl substituents sterically hinder interchain hydrogen bonding and chain reassociation during cooling	Suppresses retrogradation and syneresis; improves freeze–thaw stability; maintains paste clarity during cold storage	Fu et al. (2019); Tran et al. (2008); Shaikh et al. (2017)
Acetylation (E1420; E1422 in combination)	Acetyl groups substituted at hydroxyl positions disrupt interchain hydrogen bonding and reduce tendency for chain alignment	Reduces retrogradation and gel firming during cold storage; improves paste clarity	Subroto et al. (2023); Shaikh et al. (2017); Tan et al. (2014)
Dual modification (cross‐linking + HP or acetylation)	Combines covalent granule reinforcement with steric disruption of chain reassociation to address both processing and storage stability simultaneously	Withstands severe thermal and acid processing conditions while resisting cold‐storage retrogradation; broader functional range than single modification	Lagunes‐Delgado et al. (2024); Punia Bangar et al. (2024); Tan et al. (2014)
Acid thinning (thin‐boiling starch)	Controlled hydrolysis of glycosidic bonds reduces molecular weight and decouples hot paste viscosity from cold gel strength	Low hot‐paste viscosity enabling clean mold deposition; high cold gel strength upon cooling	Ulbrich et al. (2016); Ulbrich and Flöter (2019); Pereira et al. (2022)
Pregelatinization (cold‐swelling starch)	Pre‐cooking and drying disrupts granule structure; starch hydrates and develops viscosity without applied heat	Provides thickening in cold‐process and low‐temperature systems; rapid viscosity development on hydration	Lee and Yoo (2023); Roman et al. (2022)
OSA modification	Hydrophobic octenyl groups grafted onto starch chains create amphiphilic character enabling interfacial adsorption at oil–water interfaces	Oil‐in‐water emulsification and stabilization; fat replacement in baked systems; improved dough extensibility in fat‐reduced formulations	Roman et al. (2022); Dapčević Hadnađev et al. (2014)
Waxy starch selection (> 95% amylopectin)	Near‐zero amylose content eliminates the primary retrogradation pathway; residual amylopectin retrogradation proceeds at substantially lower rate	Minimal retrogradation during cold storage; stable gel structure; improved freeze–thaw resistance without chemical reagent use	Fu et al. (2019); Kashi and Razavi (2024); Verbeken et al. (2004)
Physical modification (HMT; annealing)	Reorganizes starch chain packing and crystallinity through controlled heat and moisture treatment without chemical reagents	Improved thermal stability and elevated gelatinization temperature; partial retrogradation resistance; clean‐label compliant	Fonseca et al. (2021); Bogdanoff et al. (2025)

TABLE 2.

Starch functional role and recommended modification strategy across sweet food product categories (conventional formulations).

Product category	Matrix conditions	Main starch function	Native starch/starch‐system limitation	Recommended strategy (conventional formulations)	Evidence basis
Caramel and toffee	Low moisture (6%–18%); sucrose/glucose syrup ≈71%–74% of formulation solids; cooking at 118°C–130°C; high shear	Dispersed particulate phase; yield stress modulation; cold‐flow resistance	Incomplete gelatinization in low water; granule disruption under shear; erratic rheology	Cross‐linked waxy starch	Mechanistic synthesis; no caramel‐specific experimental validation
Gummies and jelly candy	Up to 75% sugar solids; hot depositing; extended curing (~45°C, up to 72 h)	Primary gel former in starch‐based jelly candy; co‐structurant in gelatin gummy systems	Excessive hot viscosity; overly firm or poorly balanced cold gel	Acid‐thinned corn or cassava starch	Direct evidence (Ulbrich et al. 2016; Ulbrich and Flöter 2019; Pereira et al. 2022; Marfil et al. 2012)
Hard candy	Very low moisture (2%–5%); cooking to 135°C–160°C; amorphous glassy matrix at use temperature	Mogul starch as processing aid only; glucose syrup as starch‐derived structurant	Insufficient water for gelatinization; intact starch granules remain inert in the glassy matrix	DE‐selected glucose syrup for Tg and crystallization control; native corn starch only as mogul mold medium	Direct evidence (Hartel et al. 2018; Ozel et al. 2024; Ergun et al. 2010)
Cookies and biscuits	Low moisture (1%–5%); 33%–42% sucrose, 9%–18% fat; dough water ~20% on flour basis	Structural filler; must remain largely ungelatinized to preserve dough flow and spread	Damaged starch competes for dough water; reduces spread and increases hardness	Low‐damaged soft wheat flour (particle size > 150 μm; low water retention capacity)	Direct evidence (Barak et al. 2014; Barrera et al. 2007; Pareyt and Delcour 2008)
Fruit fillings	Acidic (fruit‐dependent pH); 60%–65% TSS; thermal cooking; cold and frozen distribution	Primary gel former; bake‐stable thickener; freeze–thaw resistant structurant	Acid hydrolysis during cooking; retrogradation syneresis; freeze–thaw network collapse	Dual‐modified waxy corn starch (industrial); tapioca‐LMP‐calcium system (validated clean‐label alternative)	Direct evidence (Agudelo et al. 2014a, 2014b)
Chocolate fillings	Fat‐continuous matrix (cocoa butter base); cocoa and milk solids; secondary baking exposure	Structural stabilizer within fat‐continuous starch‐gum co‐network	Insufficient baking stability; post‐bake syneresis (baking stability index 80% with corn starch alone)	Corn starch combined with carboxymethyl cellulose (baking stability index 96.8%)	Direct evidence (Kumar, Alam, et al. 2026)
Honey fillings	High‐sugar honey base; fat‐continuous (cream filling) or aqueous hydrocolloid formats	Body contributor in fat‐continuous format; absent in aqueous format	Functional contribution not isolated (fat‐continuous); not required (aqueous)	Not established	Research gap; starch function not isolated
Jams and fruit preserves	Acidic (pH 3.0–3.5); 60%–65% TSS; thermal cooking; cold and frozen distribution	Secondary reinforcer within pectin network; water‐binding stabilizer	Acid hydrolysis; retrogradation syneresis; freeze–thaw damage during distribution	Cross‐linked acetylated starch (E1422) at 15% w/w (blueberry jam) to 20% (apple jam)	Direct evidence (Tan et al. 2014; Zhang et al. 2016)
Custards (standard/pasteurized)	Aqueous dairy; pasteurization; cold storage; diphasic starch‐fat‐protein system	Primary heat‐activated thickener; continuous gel network formation	Retrogradation‐driven syneresis and cold‐storage gel firming	Hydroxypropylated starch; acetylated starch as alternative	Direct evidence (Shaikh et al. 2017; Nishida and Watanabe 2024)
Custards (UHT/retort)	Aqueous dairy; sterilization shear and high temperature; cold storage	Primary thickener under severe thermal and mechanical processing	Granule disruption under sterilization conditions; retrogradation during cold storage	Cross‐linked starch; dual‐modified for combined processing and storage protection	Mechanistic synthesis; no direct UHT custard validation
Milk puddings	Dairy with κ‐carrageenan and milk proteins; sterilized at 120°C; cold storage	Phase‐volume and water‐immobilization ingredient in three‐component gel system	Granule breakdown at sterilization temperature; retrogradation syneresis during cold storage	Cross‐linked acetylated waxy corn starch (E1422) at ~1%; concentration calibration critical	Direct evidence (Verbeken et al. 2004, 2006; Lin et al. 2025)
Dairy mousse	Foam system; proteins and hydrocolloids as primary stabilizers at air‐water interface	Secondary or absent; foam stability governed by proteins and hydrocolloids	Starch role in foam stability uncharacterized	Not established	Research gap; no starch‐specific validation

5.1. High‐Solids Amorphous Confections: Starch in Caramel and Toffee

The formulation challenge for starch in caramel and toffee is structurally paradoxical: the matrix conditions that create the need for body and cold‐flow control, low moisture, high sugar concentration, and elevated cooking temperatures, are precisely the conditions that restrict native starch gelatinization and limit its functional contribution. Both products are high‐solids, amorphous sugar confections, but they occupy distinct positions within that category. Caramel is produced by cooking sucrose, glucose syrup, milk solids, and fat to approximately 118°C–125°C, yielding a product with a final moisture content typically in the range of 6%–18%; at 8%–12% moisture the material is soft and chewy yet capable of holding shape, while systems above 15% moisture flow readily and those below 4% enter a glassy, brittle state (Wang and Hartel 2021). Structurally, caramel is an active emulsion‐filled protein gel, fat droplets chemically bonded to a cross‐linked milk protein background matrix dispersed within a continuous amorphous sucrose‐glucose syrup solution (Weir et al. 2016). Toffee occupies a more extreme position in this composition space: its higher fat content, greater total solids exceeding 85%, and lower residual moisture push the continuous phase toward an approximately 87:13 sugar: water ratio at which the material crosses from viscoelastic into brittle, toffee‐like behavior as it approaches vitrification (Hartel et al. 2018; Weir et al. ²⁰¹⁶). Glucose syrup is critical to both systems, preventing sucrose crystallization by increasing the bulk viscosity of the continuous phase and reducing the molecular mobility required for crystal nucleation; however, at excess levels, glucose syrup shifts the matrix toward greater stickiness and a higher tendency for cold flow, which reflects the delicate rheological balance these formulations must maintain (Sengar and Sharma 2014).

The primary formulation requirement for starch in these systems is not viscosity generation in the conventional sense, but yield stress modulation, the ability to impose a minimum force threshold below which the matrix resists deformation under its own weight. Caramel without added structural modifiers behaves nearly as a Newtonian liquid across the temperature range relevant to depositing and molding, meaning it cold‐flows freely during storage and tails during cutting (Barra and R Mitchell ²⁰¹³). Cold flow manifests as progressive deformation of individual pieces under gravitational loading, compromising dimensional integrity, causing pieces to fuse in packaging, and degrading product quality (Mendenhall and Hartel 2016). Starch would be expected to address this defect not by forming a continuous biopolymer network, which is structurally unachievable in the low‐moisture sugar phase of caramel, but by raising the effective volume fraction of dispersed particulate material in the matrix through partially swollen granules, thereby mechanistically increasing resistance to deformation under load (Weir et al. 2016). Simultaneously, the starch contribution must not introduce graininess, excessive hardness, or stickiness; the matrix must retain its characteristic chewiness and remain machinable through the pumping, forming, and cutting operations that impose substantial mechanical demands on the confection during manufacture (Hartel et al. 2018; Mendenhall and Hartel ²⁰¹⁶).

Under the matrix conditions of caramel and toffee, native starch is expected to gelatinize incompletely and inconsistently, for reasons traceable to the fundamental physics of starch hydration in concentrated sugar systems. Sugar molecules compete with starch granules for available water through hydrogen bonding, reducing the free water fraction accessible for granule swelling and elevating the thermal energy required to disrupt granule crystallinity, an effect that scales with both sugar concentration and molecular identity (Allan et al. 2018). As established in Section 4, sucrose concentration systematically elevates starch gelatinization temperature in a concentration‐dependent manner; given that sucrose and glucose syrup collectively account for approximately 71%–74% of total formulation solids in eating caramel (Wang and Hartel 2021), this elevation would be expected to be considerably more significant than in model starch‐sugar systems, raising the gelatinization threshold well beyond what caramel cooking conditions may reliably achieve. The consequence is partial granule swelling, some hydration occurs but full gelatinization does not, and under the shear conditions imposed by scraped‐surface heat exchangers, industrial pumps, and forming equipment, these partially swollen granules are susceptible to mechanical disruption, releasing starch polymer into the matrix in an uncontrolled manner and producing erratic viscosity rather than a stable, coherent dispersed phase (Mohamed et al. 2024). Native high‐amylose starches, while capable of forming firm retrogradation‐driven gels, require even higher cooking temperatures and tend to introduce excessive elastic recovery, promoting tailing rather than clean fracture, further limiting their suitability for conventional caramel and toffee applications (Hartel et al. 2018).

Cross‐linked starches, particularly from low‐amylose or waxy sources, are the most mechanistically appropriate choice for caramel and toffee, because cross‐linking directly addresses the dominant failure modes identified above. The introduction of covalent phosphate or adipate bridges between adjacent polymer chains reinforces granule architecture against the combined stresses of restricted hydration, thermal processing at 118°C–130°C, and mechanical shear during industrial handling; cross‐linked granules maintain structural integrity under these conditions, contributing a stable dispersed phase without rupturing and releasing uncontrolled polymer into the continuous sugar matrix (Punia Bangar et al. 2024). Under the restricted swelling environment of caramel's low‐moisture, high‐sugar phase, partial granule hydration occurs regardless of starch type; cross‐linking's critical contribution is preserving granule structural integrity under the mechanical shear of industrial processing, preventing the uncontrolled polymer release that produces erratic viscosity, and maintaining a stable dispersed particulate phase that provides the body and cold‐flow resistance that define high‐quality eating caramel (Punia Bangar et al. 2024; Wang and Hartel ²⁰²¹). For standard eating caramel at 8%–12% moisture, cross‐linking alone would be expected to address the primary formulation requirements: at these low water activities, free water for amylose chain reassociation is already severely restricted by the dense sugar matrix, meaning retrogradation‐driven hardening and syneresis, the problems that substitution modification is specifically designed to address, are not the dominant storage concern. In contrast, for applications with higher residual moisture, including softer caramel fillings, cream centers, and bakery‐filling systems intended for refrigerated storage, dual‐modified starches combining cross‐linking with hydroxypropylation become the more appropriate choice: the cross‐linked component maintains processing stability, while hydroxypropyl substituents suppress retrogradation‐driven firming and syneresis during cold or extended ambient storage (Fu et al. 2019; Lagunes‐Delgado et al. ²⁰²⁴). Pregelatinized cross‐linked starches may be particularly useful in caramel coating systems and lower‐temperature processing operations where conventional in‐process gelatinization is not achievable, as their capacity to hydrate and develop viscosity without applied heat allows functional contribution under conditions where unmodified granules would remain essentially inert (Compart et al. 2023).

Sugar reduction in caramel and toffee, most commonly achieved through partial or complete replacement of sucrose with polyols such as maltitol, isomalt, or sorbitol, fundamentally alters the matrix conditions that starch must navigate, making starch selection more rather than less critical. Replacing sucrose with polyols changes the glass transition temperature, hardness, resilience, and textural profile of the caramel system in a manner primarily driven by replacer identity and replacement level; at 50% sucrose replacement, glass transition temperature decreases substantially, shifting the matrix toward greater molecular mobility, reduced stand‐up properties, and increased susceptibility to cold flow (Mayhew et al. 2017). Simultaneously, polyols elevate starch gelatinization temperature more strongly than sucrose on an equivalent solids basis, reflecting their greater number of effective hydroxyl group interactions with starch chains in the amorphous granule regions, meaning that the already‐constrained hydration environment of caramel becomes even more restrictive for starch when polyols are present (Allan et al. 2018, 2020). These two effects compound one another: the matrix may become more mobile and more susceptible to texture instability due to Tg depression, while the starch's ability to compensate through gelatinization‐driven viscosity development is simultaneously suppressed. In polyol‐based caramel and toffee, starch selection would therefore be expected to prioritize functional independence from conventional gelatinization kinetics, favoring dual‐modified or pregelatinized cross‐linked starches that deliver structural contribution without depending on high water availability or standard thermal processing conditions.

5.2. Gel‐Structured Confections: Starch in Gummies and Jelly Candies

In gummies and jelly candies starch functions either as the primary gel‐forming agent in starch‐based jelly candies or as a co‐structuring and textural modifier in gelatin‐based gummy systems, a distinction that determines the formulation strategy and the modification approach in each context. Gummy and jelly confections are produced by dissolving sucrose, glucose syrup, and a gelling agent in water, cooking the mixture to concentrate soluble solids, depositing the hot paste into mold cavities, and curing the shaped pieces under controlled temperature and humidity to allow gel setting and surface drying (Hartel et al. 2018). In gelatin‐based gummies, the dominant commercial format, the continuous gel network is formed by gelatin at concentrations of approximately 5%–10%, within a matrix of 16%–21% moisture and up to 75% sweetener solids; in these concentrated sugar solutions, gelatin exhibits gelling and melting temperatures substantially higher than those of plain gelatin hydrogels, reflecting the constraining effect of high bulk viscosity on molecular mobility and junction zone development during network formation (Wang and Hartel 2022). In starch‐based jelly candy formats, including gum drops, orange slices, and Turkish delight‐type products, starch replaces gelatin entirely as the primary gel‐forming agent and must independently provide the mechanical strength, chewiness, and shape retention that gelatin supplies in conventional formulations (Hartel et al. 2018; Pereira and Beleia ²⁰²¹). It is important to distinguish this gelling function from the separate role of mogul process starch, which acts as a processing aid for cavity formation and surface moisture absorption during curing and is not incorporated into the finished product; this distinction is examined in detail in Section 5.3.

The defining formulation challenge in gummy and jelly candy manufacture is the opposing requirement of hot processability and cold gel strength: the hot starch‐sugar paste must remain sufficiently fluid to flow cleanly into mold cavities without tailing, as excessive hot viscosity causes paste to string rather than break cleanly during deposition, producing mold‐to‐mold weight variation and shape defects that compromise product consistency (Hartel et al. 2018; Ulbrich and Flöter ²⁰¹⁹); upon cooling and during the drying and curing stage, which in starch‐based gummy production can extend to 72 h at approximately 45°C (Pereira and Beleia 2021), the same paste must set into a gel of sufficient firmness to resist deformation during demolding and packaging, while providing the elastic chewiness and shape retention characteristic of a high‐quality gummy confection (Hartel et al. 2018). Texture must be controlled within a narrow range: excessively firm gels are perceived as hard and dry, suppress flavor perception by impeding volatile release, and are rejected by consumers; insufficiently structured gels fail to demold cleanly and undergo syneresis during storage, releasing free water at the product surface (Hartel et al. 2018; Pereira and Beleia ²⁰²¹).

Native starch is less suitable for gummy production because its intact high‐molecular‐weight chains, particularly the large amylopectin fraction, impede rapid formation of a three‐dimensional amylose‐based gel network and generate substantially higher hot paste viscosity in high‐solids sweetener solutions than is compatible with the controlled flow behavior required for clean depositing (Pereira and Beleia 2021; Ulbrich and Flöter ²⁰¹⁹). This same high molecular weight prevents native starch from providing the tender cold gel profile required for starch‐based jelly candies: the chain length that produces problematic hot viscosity also generates a firmer, less tender gel during cooling, making it impossible to optimize hot processability and cold gel texture independently within a native starch system (Pereira and Beleia 2021; Ulbrich et al. ²⁰¹⁶).

Acid thinning is the primary and most directly supported starch modification for gummy and jelly candy applications: acid conversion selectively cleaves glycosidic bonds within starch chains, reducing molecular weight to a range that decouples hot paste viscosity from cold gelation capacity, removing the high‐molecular‐weight polymer fractions responsible for excessive processing viscosity while preserving sufficient amylose chain length for cold gelation through junction zone formation during curing (Ulbrich et al. 2016). In high‐solids sugar solutions representative of gummy manufacture, acid‐thinned starch develops negligible hot paste viscosity, enabling clean depositing, while setting to a tender yet cohesive gel on cooling that provides characteristic chew and shape retention (Pereira and Beleia 2021). Acid‐thinned corn starch is the industrial standard for starch‐based jelly candies; acid‐thinned cassava starch represents a functionally equivalent alternative, but starch source and concentration are interdependent variables requiring co‐optimization, exceeding the product‐specific concentration threshold does not enhance gel quality and systematically compromises sensory performance. Gummy formulations produced with 12% acid‐thinned cassava starch were comparable in hardness, chewiness, and consumer acceptability to those produced with 8% acid‐thinned corn starch, while increasing concentration to 16% acid‐thinned cassava starch produced excessive gel firmness, diminished optical clarity, and measurable flavor suppression sufficient to significantly reduce overall consumer acceptability (Pereira et al. 2022).

In gelatin‐based gummies where starch supplements rather than replaces the primary gelling agent, acid‐modified corn starch introduces thermodynamic incompatibility with the gelatin network, driving starch granule segregation into hollow zones within the gelatin matrix and producing measurable changes in texture, notably increased opacity and reduced adhesiveness and stringiness, with the magnitude of textural modification increasing with starch concentration relative to gelatin (Marfil et al. 2012). For products requiring storage stability under refrigerated or extended ambient conditions, hydroxypropylated or dual‐modified starches can reduce syneresis and retrogradation‐driven hardening (Tran et al. 2008); however, in concentrated sucrose systems, sucrose crystallization during chilled storage can counteract the anti‐retrogradation effect of hydroxypropyl groups, potentially increasing rather than decreasing gel hardening, meaning their application requires product‐specific validation in the target sweetener matrix rather than straightforward substitution for acid‐thinned variants (Arlai and Tananuwong 2022).

Consumer demand for vegan, halal, and kosher gummies elevates starch from a supplementary texture modifier to a primary or co‐primary structural agent, but amylose retrogradation‐driven junction zones cannot fully reproduce the elastic recovery of gelatin's thermoreversible triple‐helix network, making co‐formulation with hydrocolloids, particularly pectin, carrageenan, agar‐agar, or guar gum, necessary to approach equivalent textural performance in gelatin‐free formats; among these, pectin and agar‐agar have been specifically shown to produce synergistic gel enhancement alongside starch (Ge et al. 2021; Tarahi et al. ²⁰²³).

In sugar‐reduced or polyol‐based gummy formulations, the starch challenge shifts in a specific direction: lower sugar concentrations reduce competitive hydration pressure on starch granules, allowing more complete gelatinization and greater amylose leaching into the continuous phase, which can increase gel opacity and accelerate retrogradation‐driven hardening during storage, a failure mode less pronounced in full‐sugar systems where competitive hydration limits starch swelling (Allan et al. 2018; Woodbury et al. ²⁰²³). Where polyols replace sucrose, they elevate starch gelatinization temperature more strongly than sucrose at equivalent solids concentrations, shifting the gelatinization window in ways that cannot be directly predicted from sucrose‐based formulation data (Allan et al. 2018). In these reformulated systems, hydroxypropylated starches become particularly relevant because bulky hydroxypropyl substituents sterically hinder amylose and amylopectin chain reassociation, directly suppressing the accelerated retrogradation driven by greater amylose availability in reduced‐sugar matrices (Fu et al. 2019); dual‐modified starches combining this substitution with cross‐linking further address processing stability alongside cold‐storage performance (Lagunes‐Delgado et al. ²⁰²⁴). Starch concentration in these systems also requires independent optimization, as parameters established for full‐sugar formulations cannot be directly transposed to reduced‐sugar or polyol‐based matrices.

5.3. Amorphous Sugar Glass Systems: Starch in Hard Candies

Hard candies represent a categorically distinct context for starch functionality: unlike most other sweet food categories examined in this review, the final product matrix contains no gelatinized starch, no starch gel network, and no hydrated granular starch phase. The formulation role of starch in these products is expressed almost entirely through its hydrolysis products rather than through intact granule functionality. Hard candies are produced by cooking sucrose and water, typically with glucose syrup as a doctoring agent, to approximately 135°C–160°C, reducing final moisture to approximately 2%–5%, and cooling the concentrated mass below its glass transition temperature (Tg) to form a kinetically stable amorphous glass (Ergun et al. 2010; Ozel et al. ²⁰²⁴). In this glassy state, molecular mobility is severely restricted and the product maintains its hard, transparent character as long as it remains below Tg; however, the glassy state is kinetically rather than thermodynamically stable, meaning that slow structural changes, sucrose recrystallization and moisture‐induced Tg depression, remain possible even in well‐formulated systems (Ergun et al. 2010; Kuzu et al. ²⁰²⁵). Native corn starch pre‐dried to 5%–7% moisture serves as a processing aid in the mogul molding process, forming mold cavities and absorbing surface moisture during candy setting, but is not incorporated into the final product; hard candy therefore represents the one sweet food category in this review where starch has no formulation role and its involvement is limited entirely to a processing function (Hartel et al. 2018).

Glucose syrup, a starch hydrolysis product whose composition is characterized by its dextrose equivalent (DE), reflecting the degree to which starch chains have been hydrolyzed into shorter saccharides, is the primary starch‐derived formulation ingredient in hard candy, and its selection must simultaneously address three requirements that are in inherent tension: preventing sucrose crystallization, maintaining a sufficiently high glass transition temperature, and limiting hygroscopic moisture uptake. This tension defines the central formulation trade‐off. Low‐DE glucose syrup, with a higher proportion of long‐chain saccharides, maintains elevated Tg and low hygroscopicity but leaves the system more susceptible to sucrose recrystallization and graining during storage; conversely, high‐DE glucose syrup effectively suppresses graining but introduces elevated concentrations of hygroscopic monosaccharides, glucose and fructose, that absorb atmospheric moisture, depress Tg toward ambient temperature, and drive the product surface from glassy to rubbery, producing the stickiness that characterizes over‐corrected formulations (Ergun et al. 2010; Ozel et al. ²⁰²⁴). Glucose syrup suppresses crystallization through several concurrent mechanisms: increasing the viscosity of the continuous sugar phase to impede sucrose diffusion toward crystal nuclei, adsorbing onto incipient crystal surfaces to disrupt lattice growth, and introducing a heterogeneous saccharide distribution that prevents the molecular alignment required for ordered sucrose crystal formation (Ozel et al. 2024). Navigating this trade‐off through deliberate DE selection, supplemented where necessary with maltodextrin to raise Tg, is therefore the primary formulation engineering decision in hard candy production; higher‐molecular‐weight fractions extend the kinetically stable window by reducing the plasticizing influence of low‐molecular‐weight sugars, subject to the constraint that excessively high Tg produces candy that is too hard and slow‐dissolving with impaired flavor release (Ergun et al. 2010).

Within this framework, intact native or modified starch granules have no meaningful thickening or gelling role in the finished glassy matrix: at the 2%–5% moisture content of the hard candy system, there is insufficient water for granule hydration, gelatinization, or swelling, and any ungelatinized starch present would be expected to behave as an insoluble particulate phase rather than a functional network‐forming ingredient (Ozel et al. 2024). The starch‐relevant formulation tools in hard candy are therefore exclusively its hydrolytic products, selected for their saccharide distribution and its consequences for Tg, crystallization kinetics, and moisture sorption behavior.

5.4. Low‐Moisture Baked Systems: Starch in Cookies and Biscuits

Cookies and biscuits present a formulation paradox that distinguishes them from most other sweet food categories: starch is the most abundant single component of the flour fraction yet exerts a relatively small direct influence on quality compared with fat, sugar, and protein. The analysis here focuses on soft wheat‐based sugar‐snap cookies and short‐dough biscuits, the conventional formats in which this paradox is most clearly expressed (Pareyt and Delcour 2008). The explanation lies in the matrix. These products are low‐moisture baked goods with final water contents of approximately 1%–5%; their solid fraction typically comprises 47.5%–54% flour, 33.3%–42% sucrose, and 9.4%–18% fat, with dough water at approximately 20% on a flour basis (Panghal et al. 2018; Pareyt and Delcour ²⁰⁰⁸). In this concentrated, water‐limited system, starch granules do not form a continuous gelatinized network but remain dispersed as discrete particles within a continuous phase dominated by saturated sucrose solution and fat; baking proceeds not through starch gel formation but through gravitational dough flow followed by structure fixation, with final cookie diameter determined by the extent of spread before setting (Pareyt and Delcour 2008). The functional requirement for starch in this context is, paradoxically, inactivity: starch must remain largely ungelatinized and low in water‐binding capacity so that limited dough water remains available to dissolve sucrose, sustain early‐baking dough flow, and produce the lateral spread and low height associated with quality cookies in this format; after baking, snap and crispness are properties of the brittle sucrose glass‐starch composite matrix rather than of a starch gel network (Adedara and Taylor 2021; Barrera et al. ²⁰⁰⁷; Pareyt and Delcour ²⁰⁰⁸).

Because intact starch is desirable and excessive starch hydration is not, the relevant failure mode in conventional cookies is not native starch inactivity but damaged starch: mechanically damaged starch granules absorb substantially more water than intact granules, directly competing with sucrose for the limited water available in cookie dough and reducing the free water fraction required for viscosity reduction and dough flow (Barak et al. 2014; Barrera et al. ²⁰⁰⁷). Barak et al. (2014) quantified these relationships directly: spread ratio ranged from 6.72 to 10.12 across flour fractions and correlated negatively with damaged starch content (r = −0.826) and water retention capacity (r = −0.880), with flour particle size above 150 μm consistently producing the best cookie quality. The primary starch management strategy in standard cookie systems is therefore not chemical modification but flour quality control: selecting soft wheat flour with low damaged starch content, particle size above 150 μm, and low water retention capacity, criteria that collectively maximize the free water fraction available for sucrose dissolution and dough spread (Barak et al. 2014; Barrera et al. ²⁰⁰⁷). This strategy is reinforced by a second mechanism: as established in Section 4, sucrose strongly elevates the gelatinization onset temperature of wheat starch, and under cookie conditions where dough water is progressively lost during baking, this elevation restricts starch swelling and gelatinization before the structure sets; consequently, most starch granules remain intact or only partially disrupted rather than forming a continuous gelatinized network (Pareyt and Delcour 2008; Woodbury et al. ²⁰²³). Sucrose therefore serves a dual structural function: restricting starch gelatinization during the spread phase, then vitrifying during cooling to contribute to the brittle matrix governing final cookie fracture. The implication for alternative grain systems, including barley, oat, sorghum, or gluten‐free formulations, is that these specific flour selection criteria and sucrose‐mediated starch management logic do not directly apply, as each system carries its own starch functionality, accessory components, and structural mechanisms (Adedara and Taylor 2021).

The consequences of this sugar‐starch‐water interdependence become most visible under reformulation. In sugar‐reduced systems, reducing sucrose removes its protective elevation of starch gelatinization temperature, allowing more complete gelatinization and greater amylose leaching during baking, which suppresses spread and increases hardness; at 50% sucrose reduction, biscuit factor falls from approximately 6.7 to approximately 3.4 (Blanco Canalis et al. 2018). Selecting sucrose replacers that maintain similar volumetric hydrogen bond density in solution, and therefore similar gelatinization temperature elevation, minimizes disruption to starch behavior during baking and represents the most mechanistically consistent strategy for preserving spread and crispness under sugar reduction (Renzetti and van der Sman ²⁰²²; Woodbury et al. ²⁰²³); where this is insufficient, hydroxypropylated starch can provide partial compensation by suppressing the accelerated retrogradation that occurs when sucrose's anti‐staling contribution is removed (Fu et al. 2019). Fat reduction introduces parallel challenges: fat coats flour particles, limits protein hydration and network development, and reduces dough viscosity; its removal narrows the spread window further, with spread ratio decreasing from approximately 6.31 in full‐fat controls to as low as 4.06 at high fat replacement levels (Ashwath Kumar and Sudha ²⁰²¹). OSA‐modified starch emulsions represent a viable fat replacement pathway: by structuring oil as oil‐in‐water emulsions stabilized by OSA starch, they partially restore the fat phase's lubricating and water‐barrier functions; however, OSA starch's water‐binding capacity simultaneously competes for dough water, reducing spread and increasing hardness relative to traditional shortening, and concentration must be optimized to balance fat replacement benefit against water competition (Dapčević Hadnađev et al. 2014). Hybrid gel systems combining gelatinized corn starch with structured oil have shown promise at moderate fat replacement levels in sugar‐snap cookie formats as an alternative approach where OSA starch concentration optimization proves insufficient (Roman et al. 2022).

5.5. Starch in Bakery Fillings: Fruit, Chocolate, and Honey Systems

Sweet bakery fillings—fruit, chocolate, and honey—share one formulation demand: the filling must maintain viscosity, shape, and gel integrity through the thermal stress of secondary oven baking, cold storage, freeze–thaw cycling, and moisture transfer into the surrounding pastry. Beyond this shared demand, the three matrix types present fundamentally different primary starch challenges, making it analytically inaccurate to treat them as a single product category: fruit fillings are low‐pH aqueous systems where starch acts as the primary gel former; chocolate fillings are fat‐rich multiphase systems where starch functions as a structural stabilizer within a gum network; and honey fillings are high‐sugar systems where starch's functional role is peripheral and matrix‐dependent, present as a body contributor in fat‐continuous formats but absent in aqueous hydrocolloid‐structured formats. (Patrignani et al. 2022; Alam, Madhav, et al. ²⁰²⁴).

Fruit fillings are typically formulated at pH 3.0–3.2 with approximately 35% sugar, exposing starch to two sequential thermal stress events, heating during filling preparation and a second oven exposure during pastry baking, as well as acid hydrolysis, retrogradation‐driven syneresis, and freeze–thaw damage during refrigerated or frozen distribution (Agudelo et al. ^{2014a, 2014b}; Alam, Dar, and Nanda ²⁰²⁴; Alam, Pant, et al. ²⁰²⁴). Native starch is vulnerable across these dimensions: acid progressively cleaves glycosidic bonds during cooking at low pH, reducing thickening capacity; upon cooling, amylose retrogradation causes gel contraction and syneresis; and during secondary baking, the weakened starch network cannot prevent water migration from the filling into the surrounding dough (Agudelo et al. ^2014b; Alam, Dar, and Nanda ²⁰²⁴). The industrial solution is a multiply‐modified waxy corn starch in which cross‐linking provides resistance to acid and thermal degradation (Punia Bangar et al. 2024), and hydroxypropylation or acetylation suppresses cold‐storage chain reassociation and improves paste clarity (Fu et al. 2019; Subroto et al. ²⁰²³). The waxy base minimizes retrogradation‐prone amylose, and the industrial standard integrates these modifications into a single dual‐modified starch that delivers the combined stability profile required across cooking, secondary baking, and frozen distribution (Agudelo et al. ^2014a; Lagunes‐Delgado et al. ²⁰²⁴). A clean‐label alternative is directly supported by experimental evidence: replacing 10% of native tapioca starch with low‐methoxyl pectin in a calcium‐containing system at pH 3 significantly elevated peak, hot paste, and cold paste viscosities, reduced breakdown, and strengthened gel elasticity to levels statistically comparable to the modified waxy corn starch control; in freeze–thaw and baking tests performed in both open and closed pastry formats, the tapioca‐pectin‐calcium system showed no syneresis and equivalent bake stability, establishing it as a viable pathway for clean‐label fruit filling formulation (Agudelo et al. ^{2014a, 2014b}). When sugar is reduced, reformulation must account for hydrocolloid functionality: high‐methoxyl pectin requires above 55% soluble solids for optimal gelation, so reducing sugar below this threshold collapses gel structure unless the system is redesigned around low‐methoxyl pectin with calcium, which maintains gel integrity independently of soluble‐solids concentration (Alam, Dar, and Nanda ²⁰²⁴; Alam, Pant, et al. ²⁰²⁴).

Chocolate fillings occupy a fundamentally different matrix, fat‐rich and cocoa‐based, with a continuous phase of fat, cocoa solids, milk solids, and sugar, in which starch does not form an aqueous gel but acts as a structural stabilizer within a starch‐gum network. In this matrix, corn starch alone provides insufficient thermal stability: a baking stability index of 80% and syneresis of 7.60% before and 4.25% after baking reflect starch's inability to adequately immobilize water and maintain network integrity within the fat‐rich multiphase environment under oven conditions (Kumar, Alam, et al. ²⁰²⁶). The most effective correction is not chemical starch modification but hydrocolloid supplementation: combining corn starch with carboxymethyl cellulose raised the baking stability index to 96.80%, reduced pre‐bake syneresis to 1.12%, and post‐bake syneresis to 0.96%, outperforming all other gum combinations tested; the mechanism operates through enhanced water immobilization, stronger junction zone formation, and reinforced intermolecular interactions that maintain viscoelastic structure and prevent filling collapse or leakage during croissant baking (Kumar, Alam, et al. ²⁰²⁶).

Honey fillings present the most peripheral and least resolved role for starch within the bakery filling category. In fat‐based honey cream fillings, corn starch has been incorporated at substantial levels alongside xanthan gum and oat fiber in a cocoa butter‐continuous matrix, where, consistent with its role in fat‐continuous filling systems, ungelatinized starch granules would contribute bulk and structural mass as a dispersed phase; however, since starch concentration was not varied across formulations, its specific functional contribution to texture and stability in this matrix was not isolated (Patrignani et al. 2022). In aqueous hydrocolloid‐based honey fillings, starch is absent entirely: an optimized combination of xanthan gum, guar gum, and gelatin converts honey's Newtonian flow to a viscoelastic non‐flowing matrix stable at temperatures up to 220°C without starch as a structural component (Alam, Madhav, et al. ²⁰²⁴). Across both formats, starch's functional role in honey fillings remains peripheral and insufficiently characterized to support product‐specific modification recommendations, distinguishing honey fillings as the bakery filling category where starch selection is currently guided by inference rather than direct experimental evidence.

5.6. Fruit Gel Systems: Starch in Jams, Fruit Preserves, and Fruit Purees

Jams, fruit preserves, and fruit purees present a distinct starch challenge from bakery fillings: the product itself is the fruit gel, and starch must reinforce gel structure, viscosity, and water retention within an inherently acidic, sugar‐dependent, intermediate‐moisture fruit matrix. In traditional jam, formulated at approximately 45% fruit and 55% sugar and concentrated to 60%–65% TSS, pectin is the primary gel‐forming agent and starch functions as a secondary reinforcing component, supplementing the pectin network with additional yield stress, consistency, and thermal stability during cooking (Agudelo et al. ^2014a; Alam, Dar, and Nanda ²⁰²⁴; Kumar, Alam, et al. ²⁰²⁶); in bake‐resistant formats, starch must additionally maintain structural integrity during oven exposure (Assifaoui et al. 2024).

The functional requirements for starch in this matrix are multiple and simultaneous. Jam must hold its shape at rest without spreading, a property governed by yield stress, the minimum force required to initiate flow, while also spreading smoothly under the force of a knife, which requires viscosity to decrease progressively as shear is applied. In quality‐optimized conventional mango jam at 65% sugar and 1% pectin, yield stress is approximately 72.8 Pa, with values ranging from 45.2 to 112 Pa across the full formulation space as sugar concentration, pectin level, and pH vary, confirming that jam rheology is acutely sensitive to ingredient balance (Basu and Shivhare 2010). Starch must contribute supplementary viscosity and water‐binding capacity to this yield stress framework, maintaining network integrity and preventing syneresis through thermal processing, cold storage, and distribution without compromising the shear‐thinning spreadability on which consumer acceptance depends.

Starch's functional contribution in this matrix is inseparable from its interaction with the pectin network. Starch does not form an independent gel in jam; rather, swollen starch granules physically fill and reinforce the continuous pectin matrix, while starch chains interact with pectin through hydrogen bonding to suppress short‐term amylose retrogradation and reduce free water available for expulsion from the network; the net effect is increased viscosity, reduced syneresis, and improved structural stability of the combined system (Assifaoui et al. 2024). This cooperative relationship depends on formulation balance: in well‐designed systems starch and pectin complement rather than compete, but excessive starch concentration can divert water away from pectin chain hydration during cooking, weakening the primary gel network before starch gelatinization is complete.

Native starch is vulnerable across the key stresses of this matrix: under the acidic pH typical of fruit systems, acid can promote starch chain hydrolysis during high‐temperature cooking, reducing molecular weight and thickening capacity (Zhang et al. 2016); during storage, amylose retrogradation drives gel contraction and water separation (Tan et al. 2014); and during frozen or refrigerated distribution, freeze–thaw cycling promotes amylose and amylopectin crystallization that expels bound water on thawing, producing irreversible syneresis that native starch cannot resist without structural modification (Fu et al. 2019). These failure modes are compounded in heat‐resistant jam formats, where the gel must survive direct oven exposure at temperatures that further degrade unprotected starch structure.

These failure modes require modification strategies targeting different processing stages. Cross‐linking addresses the cooking stage, providing acid and thermal resistance that prevents viscosity loss during high‐temperature jam preparation (Punia Bangar et al. 2024). Hydroxypropylation and acetylation address the storage and distribution stage, suppressing amylose and amylopectin retrogradation, reducing syneresis, and in the case of acetylation also improving paste clarity (Fu et al. 2019; Subroto et al. ²⁰²³). Because acid‐thermal degradation during cooking and retrogradation‐syneresis during storage and frozen distribution are sequential rather than alternative stresses, dual modification combining cross‐linking with acetylation is the industrially appropriate strategy: cross‐linking stabilizes structure during cooking while acetylation protects against retrogradation and water separation across the storage and distribution lifecycle (Lagunes‐Delgado et al. ²⁰²⁴). This was directly demonstrated in apple jam: cross‐linked acetylated starch at 20% produced a compact, fine, homogeneous microstructure with stronger viscoelastic properties than native starch controls, establishing this level as the industrially appropriate concentration for apple jam manufacture (Tan et al. 2014).

Product‐specific evidence further establishes that cross‐linked starch delivers both structural stability and a pigment‐protective function in heat‐resistant formats. In heat‐resistant blueberry jam formulated at 25% sugar and 1% pectin, cross‐linked corn starch (distarch phosphate) at 15% w/w provided complete shape retention during baking at 180°C for 20 min, forming a finer, more homogeneous network through interaction between pectin and swollen starch granules during heating; hydrogen bonding between starch hydroxyl groups and anthocyanin polar groups additionally contributed to pigment stabilization and color protection during baking, a functional advantage particularly relevant to berry‐based jams where color retention is a primary quality indicator (Zhang et al. 2016).

Where clean‐label reformulation is a priority, physically modified starch using heat‐moisture treatment or annealing improves thermal stability and suppresses retrogradation without chemical reagents (Fonseca et al. 2021); however, in the severe acid environment of fruit systems, where glycosidic bond hydrolysis during high‐temperature cooking represents the dominant starch degradation pathway, physical modification alone would be expected to provide only partial protection compared to the acid resistance conferred by chemical cross‐linking.

This interdependence defines the central challenge in reduced‐sugar formulation. In sour cherry jam with stevia, reducing sucrose decreased yield stress and consistency index primarily through the accompanying TSS reduction; pectin concentration was the most effective compensating variable, with the optimized formulation at 36.5% sucrose, 0.277% pectin, and 0.30% stevia recovering acceptable rheological and sensory properties (Nourmohammadi et al. 2021). Sugar alcohol substitution presents a parallel challenge: in sorbitol‐substituted mango jam, the formulation with 75% sorbitol substitution achieved the highest consumer acceptability but showed reduced hardness reflecting weakened pectin junction zones compared with sucrose‐based controls (Basu and Shivhare 2010). In both cases, the formulation principle is consistent: when sucrose is reduced and TSS drops, the starch‐pectin system must be redesigned rather than simply maintained, because the structural contribution of sucrose cannot be recovered by sweetener substitution alone. Based on the failure mode analysis established in this section, cross‐linked hydroxypropylated starch would be expected to represent the most appropriate modification type for reduced‐sugar jam reformulation: cross‐linking would compensate for the increased acid vulnerability that accompanies higher water activity in low‐TSS systems, while hydroxypropylation would replace the retrogradation‐suppressing and water‐binding functions that sucrose previously provided in the full‐sugar matrix (Fu et al. 2019; Punia Bangar et al. ²⁰²⁴).

5.7. Dairy Gel and Foam Desserts: Starch in Custards, Puddings, and Mousses

In custard, starch gelatinization is the dominant process determining rheological outcome: starch was confirmed as the central component for custard rheological characterization, with all starch‐containing systems exhibiting non‐Newtonian behavior and high consistency indices, and starch and disaccharides, sucrose and lactose, acting synergistically to enhance the consistency index beyond what either component achieves alone (Nishida and Watanabe 2024). Structurally, custard functions as a diphasic system in which the stationary phase consists of starch and hydrocolloids while the mobile phase comprises fat and protein components, meaning that starch reformulation affects both phases simultaneously (Kashi and Razavi 2024).

Native starch fails in custard primarily through retrogradation‐driven gel firming and water expulsion during cold storage: Shaikh et al. (2017) showed that custards prepared with native pearl millet starch exhibited 36.2% syneresis after 7 days of refrigerated storage and a setback viscosity of 51.0 BU reflecting strong retrogradation tendency; hydroxypropylated starch eliminated syneresis entirely and reduced setback viscosity to 19.0 BU, with no retrogradation peak detected after 14 days. Hydroxypropyl groups suppress chain reassociation by steric hindrance, maintaining water within the gel network throughout refrigerated storage (Fu et al. 2019); acetylated starch similarly showed no retrogradation peak after 14 days with setback viscosity of 29.5 BU, substantially lower than native starch but higher than the 19.0 BU achieved by hydroxypropylation, confirming hydroxypropylation as the stronger anti‐retrogradation intervention in this custard system (Shaikh et al. 2017). For industrial custards processed under UHT or retort conditions, the high shear and thermal stress during sterilization would be expected to require cross‐linked starch to maintain granule integrity, by analogy with the well‐established shear and thermal resistance properties of cross‐linked starch in high‐stress processing contexts (Punia Bangar et al. 2024); dual modification combining cross‐linking with hydroxypropylation or acetylation would be expected to address both processing stability and cold‐storage retrogradation simultaneously, extending the custard‐demonstrated anti‐retrogradation benefits with the processing protection that cross‐linking provides in industrial thermal contexts (Lagunes‐Delgado et al. ²⁰²⁴; Shaikh et al. ²⁰¹⁷).

In low‐fat custard where sucrose is partially or fully replaced with xylitol, waxy corn starch provides a multifunctional structural strategy: replacing native corn starch with waxy corn starch reduced hardness from 13.55 to 1.66 N, reduced syneresis over 5 days from 10.29% to 0.02%, and achieved 98.08% creaming stability and 99.99% water holding capacity with improved smoothness and creaminess scores; however, increased adhesiveness and perceived thickness indicate that concentration optimization is necessary to balance structural benefit against sensory over‐structuring (Kashi and Razavi 2024). For the same reformulation objective under clean‐label constraints, high hydrostatic pressure treatment of waxy corn starch offers a physically modified alternative: combined with xylitol and fat reduction, HHP‐treated waxy corn starch prevented syneresis after 5 days at 4°C, increased consistency and adhesiveness, and reduced enzyme sensitivity and glucose release without chemical modification (Kashi and Razavi 2024).

In milk pudding, starch functions as a phase‐volume and water‐control ingredient within a three‐component structural system of swollen starch granules, κ‐carrageenan network, and milk proteins, rather than as the primary gel former (Verbeken et al. 2004). Starch affects texture primarily through the exclusion effect: as granules swell, they occupy volume and concentrate κ‐carrageenan in the remaining continuous aqueous phase, raising complex modulus and gelation temperature; large‐deformation gel strength, however, is governed mainly by the κ‐carrageenan network reinforced by milk protein interactions, because swollen starch granules deform readily under penetration and contribute little to fracture behavior (Verbeken et al. 2004). Native maize starch is adequate within this exclusion and water‐immobilization role in pasteurized pudding systems, but cannot withstand severe heat treatment at 120°C in sterilized dairy desserts. For sterilized formats, adipate cross‐linked acetyl‐substituted waxy maize starch is required: its heat and shear resistance maintains granule integrity during processing, while its near‐zero amylose content and acetyl groups collectively limit retrogradation and water release during cold storage (Verbeken et al. 2006).

In refrigerated milk pudding, cross‐linked acetylated waxy corn starch (acetylated distarch adipate, E1422) is the appropriate modification type, with starch concentration requiring calibration rather than maximization: increasing starch from 1% to 5% at fixed polysaccharide concentration decreased gel strength and increased syneresis, attributed to the highly branched amylopectin structure interfering with hydrocolloid network formation at higher concentrations (Lin et al. 2025). The optimal formulation balancing sensory acceptability and syneresis control over 14 days of refrigerated storage was 5% sucrose, 0.3% gellan gum, and 1% cross‐linked acetylated waxy corn starch (Lin et al. 2025).

Dairy mousse presents the least characterized role for starch within the dairy dessert category: it is a foam system in which quality depends on the size, distribution, and stability of dispersed air bubbles rather than on a starch gel network, with primary stabilization achieved by foam‐active proteins and hydrocolloids directly at the air‐water interface (Hu and Meng 2024). The specific contribution of starch, and of modified starch in particular, to foam stability and textural outcome in mousse systems has not been established in the product‐specific literature reviewed here and represents a research gap identified in Section 7.

6. Cross‐Cutting Formulation Challenges

6.1. The Clean‐Label Paradox: Functional Performance vs. Consumer and Regulatory Demand

The clean‐label movement, driven by consumer preference for natural, minimally processed ingredients with recognizable label declarations, represents the most structurally significant commercial pressure on starch formulation in contemporary sweet food production. Chemically modified starches are classified as food additives carrying E‐number or INS coding and must be declared as “modified starch” on ingredient lists; physically and enzymatically modified starches, by contrast, are classified as ingredients and can be labeled simply by botanical source, a distinction consumers directly associate with naturalness and safety (Park and Kim 2020). This rejection is consumer‐perception‐driven rather than strictly regulatory: Bogdanoff et al. (2025) emphasize that ingredient familiarity shapes clean‐label acceptability, even when replacing functional chemically modified ingredients may require higher usage levels, increase costs, or reduce sensory quality. Physically modified starches have historically accounted for only approximately 5% of food‐modified starches worldwide, indicating that consumer‐led demand and industrial formulation reality remain substantially misaligned (Bogdanoff et al. 2025; Park and Kim ²⁰²⁰).

The persistence of this misalignment reflects a genuine functional constraint rather than industrial inertia. Clean‐label starches, including physically and enzymatically modified alternatives, often fall short of matching their chemically modified counterparts under the conditions sweet food formulation demands most: Kataria et al. (2026) document reduced thermal and shear stability attributable to the absence of cross‐linking, susceptibility to acid hydrolysis and poor water binding in high‐sugar matrices, elevated freeze–thaw syneresis, and greater retrogradation tendency during cold storage, the same failure modes that drove the modified starch recommendations across Sections 5.1 through 5.7 of this review. Physical modification through heat‐moisture treatment and annealing remains a genuinely viable clean‐label pathway, but its effectiveness is application‐dependent and does not consistently reproduce the heat and shear tolerance of cross‐linked starches or the retrogradation resistance of substituted ones under high‐stress processing conditions (Fonseca et al. 2021; Kumar, Bangar, et al. ²⁰²⁶).

The challenge is further compounded by the absence of a unified regulatory framework for clean‐label. The term lacks a legally standardized definition across major jurisdictions; it is generally understood to refer to foods made with simple, minimally processed, and recognizable ingredients without artificial additives or synthetic chemicals, but this interpretation remains subjective and inconsistent across markets and regulatory bodies (Anjali et al. 2024; Asioli et al. ²⁰¹⁷). Regional interpretation diverges further: what constitutes a clean‐label starch ingredient in one market may not satisfy the consumer expectations or labelling conventions of another, meaning that for sweet food manufacturers the choice between cross‐linked acetylated starch and a heat‐moisture‐treated alternative carries labelling consequences that are simultaneously consumer‐driven, market‐specific, and unresolved by any international standard (Bogdanoff et al. 2025; Kataria et al. ²⁰²⁶).

6.2. Starch–Flavor Binding: Retention, Release, and Sensory Delivery Trade‐Offs

Beyond its structural role, starch acts as an active flavor modulator in sweet food systems through the capacity of amylose to form non‐covalent V‐type inclusion complexes with volatile aroma compounds. The single helical conformation of amylose presents a hydrophobic internal cavity that accommodates small hydrophobic molecules, reducing their headspace availability and delaying release. High‐amylose starches generally show greater capacity for this type of complexation than waxy starches, which contain little amylose available for helix‐based retention (Ma et al. 2022). This retention is neither uniform across starch sources nor across aroma compound polarity: Emmanouil et al. (2025) demonstrated that diacetyl, a polar buttery compound central to dairy and confectionery flavor profiles, required an activation energy of 98.65 kJ/mol for release from wheat starch compared with only 19–26 kJ/mol for rice, corn, and potato starch, while the non‐polar terpene dl‐limonene showed a distinct source‐dependent pattern, confirming that changing starch botanical source for textural reasons simultaneously alters flavor delivery in ways that are compound‐specific and not directly predictable.

The challenge for sweet food formulation is that the flavor delivery consequences of starch selection and modification are poorly characterized for the specific starch types deployed across the product categories in this review. The modification types recommended throughout Sections 5.1, 5.7, cross‐linking, hydroxypropylation, acetylation, and waxy starch selection, have been characterized for their textural and stability contributions but not for their effects on amylose availability and inclusion complex capacity: cross‐linking and substitution modify chain conformation and mobility in ways that would be expected to alter flavor complex formation, while waxy starch substantially reduces the amylose available for helix‐based retention, yet whether any of these changes improve or impair flavor delivery in custards, jams, confections, and dairy desserts has not been experimentally determined. During refrigerated storage, retrogradation independently compounds this problem: as gel firmness increases and water mobility decreases over 1–21 days at 4°C (Liu et al. 2021), diffusion of dissolved volatile compounds through the starch matrix becomes more restricted, reducing flavor release rate even where total volatile concentration remains unchanged (Emmanouil et al. 2025; Su et al. ²⁰²¹). The systematic characterization needed to integrate these variables, across modification types, botanical origins, and product‐relevant conditions, into a predictive framework for flavor delivery has not been established, leaving starch selection for sensory function without the evidence base that currently supports textural optimization.

6.3. Predictive Modeling Limitations: From Model Systems to Multi‐Ingredient Sweet Food Matrices

Predicting starch functionality in sweet food formulation from model system data represents a persistent and inadequately resolved challenge: the rheological and textural behavior of starch in simple aqueous systems does not reliably transfer to real food product matrices. Le Thanh‐Blicharz and Lewandowicz (2020) demonstrated this directly by comparing starch clustering across pastes, binary mixtures, and four food products including pudding and acidic jelly; the clustering of real products did not resemble that of starch pastes or binary mixtures, confirming that starch model systems are useful only for rapid thickener screening and cannot serve as a final reference for food product quality design. The divergence is mechanistically driven: proteins, fats, acids, salts, and co‐solutes in real matrices create interaction effects that override simple model predictions and can reverse the expected direction of starch behavior entirely (Zhang et al. 2021). Arlai and Tananuwong (2022) demonstrated this reversal specifically for modified starch in sweet food‐relevant conditions: hydroxypropyl distarch phosphate reduced hardening and crystallinity in water‐based gels as expected from its modification chemistry, but in 45°. Brix sucrose syrup and coconut milk the same modification produced greater chilled‐storage hardening and increased crystallinity, attributed to sucrose crystallization and amylose‐lipid complex formation mechanisms that are absent in water‐based models but active in concentrated sweet and fat‐containing food matrices.

The inadequacy of conventional approaches is observable even before full food matrix complexity is added. In binary starch‐sweetener systems, bulk parameters such as water activity, solids content, and viscosity correlate with wheat starch gelatinization temperature across broad concentration ranges but weaken significantly within similar sweetener concentration ranges, while molecular stereochemistry, specifically the orientation of equatorial and exocyclic hydroxyl groups, explains differences among sweeteners with identical carbon number that bulk parameters cannot capture (Allan et al. 2018). In industrial settings, reliance on water‐based models or single‐point pasting data can lead to misjudgment of gelatinization temperature, textural set point, or processing window, resulting in trial‐and‐error formulation cycles and inconsistent product performance (Balet et al. 2019). Machine learning has demonstrated promise in addressing this non‐linearity: a model predicting starch gelatinization temperature across nineteen sugars and sugar alcohols in a controlled binary system achieved accuracy within 1.6%, demonstrating that multivariable approaches capture molecule‐specific interactions that single‐parameter correlations miss (Allan et al. 2018, 2020). However, this success has not been extended to multicomponent sweet food matrices where simultaneous fat, protein, acid, hydrocolloid, and multiple sugar interactions operate, leaving starch selection for sweet food formulation without a validated predictive framework that integrates matrix composition, modification type, and processing conditions into actionable formulation guidance. Future predictive tools must move beyond binary and model systems to account for the coupled, matrix‐specific interactions that define starch behavior in real sweet food products, the same interactions that make product‐specific starch selection, rather than generic modification guidance, the central argument of this review.

7. Future Research Directions

Several formulation recommendations advanced in this review are grounded in well‐established starch modification principles but have not been directly validated in their target product matrices. For caramel and toffee, the recommendations for cross‐linked waxy starch for cold‐flow resistance, dual‐modified starch for moisture‐sensitive formats, and pregelatinized cross‐linked starch for low‐temperature operations were derived by applying established modification properties to the low‐moisture, high‐shear caramel matrix rather than from caramel‐specific experimental evidence; no published study has directly tested these modification types in caramel under controlled formulation conditions. For industrial custards processed under UHT or retort conditions, the proposal that cross‐linking and dual modification address both processing stability and cold‐storage retrogradation simultaneously was similarly framed as mechanistic inference rather than product‐specific demonstration. For sugar‐reduced systems across jam, gummy, and confection categories, hydroxypropylated starch as the compensatory strategy for accelerated retrogradation when sucrose is removed is mechanistically consistent and analytically supported in each case, but has not been directly validated in actual product matrices; in concentrated polyol gummy systems specifically, the anti‐retrogradation effect of hydroxypropyl groups may be counteracted by competitive crystallization mechanisms that require product‐specific investigation. Product‐specific experimental validation of these recommendations represents the most direct research priority arising from this review's analytical contributions.

Beyond validation of inference‐based recommendations, this review identified several product categories where starch's functional role remains insufficiently characterized to support formulation guidance. In honey‐based fillings, the contrast between starch's inclusion in fat‐continuous honey cream formats, where its specific contribution was not isolated, and its complete absence from aqueous hydrocolloid‐structured formats raises fundamental questions about starch's functional boundary in honey systems that no current study addresses. In reduced‐sugar milk pudding, the behavior of cross‐linked acetylated waxy corn starch under partial or complete sucrose replacement has not been directly investigated; compensatory hydrocolloid redesign addresses gel integrity but leaves starch's specific role under reduced‐sucrose conditions uncharacterized. In dairy mousse, starch's potential contribution to continuous‐phase viscosity and drainage resistance has not been examined in peer‐reviewed formulation studies, leaving its applicability to foam‐structured dairy desserts entirely open. In gelatin‐free gummy formulations, starch‐hydrocolloid combinations improve gel structure but cannot yet fully reproduce gelatin's elastic recovery and thermoreversibility, and the specific combination parameters that best approximate gelatin performance remain unestablished.

At a broader level, three interconnected framework developments would substantially advance sweet food starch selection beyond its current case‐by‐case empirical basis. Systematic comparative performance data for clean‐label modified starches against chemically modified counterparts is needed specifically in the high‐stress sweet food matrices identified in this review, where the performance gap is most consequential and where clean‐label viability has not been established; such data would provide formulators with evidence‐based clean‐label decision criteria rather than general performance characterizations. The effect of modification type on amylose availability and flavor complex‐forming capacity requires systematic characterization in product‐relevant sweet food matrices, so that starch selection can simultaneously optimize for flavor delivery alongside textural and stability function. Finally, the machine learning approach demonstrated for binary starch‐sweetener systems in Section 6.3 requires extension to multicomponent sweet food matrices: models trained on data incorporating modification type, botanical source, matrix composition, processing history, and storage conditions would provide formulators with integrated predictive guidance currently unavailable, reducing trial‐and‐error formulation cycles and accelerating evidence‐based starch selection across the product categories examined in this review.

8. Conclusion

The functional role starch plays in sweet food formulation is not fixed but matrix‐determined. In heat‐activated dairy gel systems, gelatinization builds the primary thickening network; in high‐solids confectionery systems, starch contributes as a dispersed particulate phase within a sugar‐continuous matrix; in low‐moisture baked formats, its primary requirement is controlled inactivity. Across these divergent functional states, native starch proves insufficient, unable to simultaneously resist the acid hydrolysis, retrogradation, and high‐shear conditions that different sweet food matrices impose, making the starch selection strategy itself, through modification, source control, or hydrocolloid integration, a matrix‐driven decision rather than a default choice. The organizing principle this review advances is that starch selection must be matched to the dominant failure mode of the specific matrix because across the full spectrum of sweet food systems examined, no single starch type or modification approach can serve all functional requirements simultaneously.

While sugar dominates the physicochemical environment of sweet food matrices, starch functionality is simultaneously shaped by fat, protein, acid, and hydrocolloid components that interact with starch concurrently, while processing conditions spanning high‐temperature cooking and mechanical shear through refrigerated storage and freeze–thaw distribution impose sequential and competing demands on granule integrity and structural performance. The same starch property can define product quality in one context and constitute a storage failure in another: retrogradation‐driven gelation is the functional goal in gummy confections but a textural defect in chilled dairy systems, illustrating why starch strategy must be sensitive not only to matrix composition but to the specific quality outcome each product requires. Reformulation amplifies this complexity further: replacing sucrose does not simply remove a sweetener but changes the fundamental nature of the starch‐matrix interaction because each alternative sweetener elevates starch gelatinization temperature to a different degree and modifies water activity through distinct molecular mechanisms, making starch behavior in reformulated systems poorly predicted by full‐sugar reference data.

The recommendations in this review span from directly evidenced to analytically synthesized, and that distinction is made explicit throughout. For a subset of product categories and reformulated contexts, where extreme matrix conditions, sucrose replacement with alternative sweeteners, or fat substitution with starch‐based alternatives alter the starch‐matrix interaction in ways not yet product‐specifically characterized, the modification recommendations represent mechanistically reasoned hypotheses rather than validated guidance. Certain product categories represent a different kind of limitation: in honey‐based fillings starch is present but its specific functional contribution has not been isolated, and in dairy mousse its potential contribution to foam system stability remains uncharacterized; in both cases this review identifies the boundary of current knowledge rather than advancing claims beyond it. Together these limitations point to specific research priorities for the field: product‐specific experimental validation, characterization of starch's role in underexplored matrices, and the development of predictive tools that integrate matrix composition, processing conditions, and sensory function alongside textural optimization into a unified framework for starch selection in sweet food formulation.

Author Contributions

Nazanin Pournemati: investigation, writing – original draft, methodology, conceptualization. Benedicta Biyimba: writing – original draft. Ariel Buzera: writing – review and editing. Idaresit Ekaette: conceptualization, writing – review and editing, supervision, methodology.

Funding

The authors have nothing to report.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.