Natural plant pigments: genes and transcription factors regulating synthesis and degradation, extraction, microencapsulation, food applications, and sensory impacts

Abstract

Natural pigments are essential for the visual attractiveness of foods, being a healthy alternative to artificial colorings. Chlorophylls, carotenoids, anthocyanins and betalains stand out as bioactive pigments that promote health benefits and contribute to disease prevention. The stability of these pigments is influenced by factors such as light and temperature, requiring strategies such as microencapsulation for protection. Encapsulation can be performed by a variety of physical and chemical techniques capable of improving the bioavailability and durability of these pigments. However, challenges remain, such as a detailed understanding of the synthesis and degradation of these pigment compounds and interactions with food matrices. Although there is extensive research on the study of isolated pigments, there is a lack of comparative reviews on the stability and acceptance of these compounds by consumers. Therefore, this study aims to analyze the molecular mechanisms, extraction trends, encapsulation of natural pigments and sensory impacts on consumer perception.

Introduction

Color is considered the main sensory attribute when it comes to acceptance and preference of a food. The use of additives in food, with the aim of making it visually attractive, is common in the chemical and food industries. However it is known that artificial colorings have potential harmful effects on human health, and there is a need to replace them with natural colorings (Souza et al., 2024a, b).

The global trend towards natural products and concerns about food safety have led to the desire to replace synthetic ingredients with natural ingredients (Devi et al., 2024; Lukitasari et al., 2024; Soutelino et al., 2024). Among the main pigments of plant origin are chlorophyll, carotenoids, anthocyanins (flavonoids) and betalains, which play an important role in photosynthesis and photoprotection. In recent years, natural pigments of plant origin have gained great visibility not only as a response to existing artificial dyes, but also as bioactive compounds of great importance for human health. These dyes have properties beneficial to health, playing an active role in prevention and combats various human disorders, including cancer, atherosclerosis, arthritis, cataracts, as well as neurodegenerative diseases (Castro-Enríquez et al., 2020; Santos et al., 2021).

The stability of pigments can be defined as their ability to resist degradation over time under different environmental and processing conditions. This is a critical factor in the selection of these compounds for technological applications (Lukitasari et al., 2024; Souza et al., 2024a, b). Several factors, such as temperature, light, pH, presence of oxygen and acidity of the medium, have a significant influence on the stability of pigments, directly impacting their chromatic characteristics, intensity and physicochemical properties (Otálora et al., 2022; Souza et al., 2024a, b). A detailed understanding of the mechanisms that lead to the synthesis and degradation of these compounds is essential for the development of optimized formulations, ensuring the durability and quality of the products in which they are used, since this understanding allows improving the yield of pigments, enabling increased production through metabolic manipulations in plants, in addition to enabling greater quality control and stability during processing, storage and application in products (Li et al., 2024; Luo et al., 2023; Wang et al., 2024a, b). Furthermore, understanding degradation mechanisms is essential to develop extraction strategies and methods that protect natural pigments against external factors. This knowledge is also essential to direct its applications in order to ensure greater stability and preservation, increasing its efficiency and durability in different technological contexts.

Due to their unstable nature, natural pigments have been the target of intense research aimed at developing new extraction methodologies and stabilization processes, such as microencapsulation (Morales-Huerta et al., 2023; Oliveira et al., 2023a, b; Souza et al., 2024a, b). This technique provides a physical barrier that protects pigments from oxidation, thermal degradation and photodegradation, in addition to controlling their release in the final product (Agarry et al., 2022; Kaur and Ghoshal, 2024; Manokari et al., 2024). Furthermore, the reduction of microparticles to dimensions below 1 μm provides advantages such as substantially improved bioavailability, solubility and adsorption capacity (Figueiredo et al., 2023; Jin et al., 2023).

The encapsulation of natural pigments can be carried out using a variety of techniques, which are divided into physical and chemical methods. Among the physical methods, stands out complex coacervation (Roman et al., 2022), fluidization (Yang et al., 2022), spray drying (Souza et al., 2024a, b), spray-chilling (Figueiredo et al., 2023; Oliveira et al., 2023a, b), freeze drying (Ledari et al., 2024) and ionic gelation (Żurek et al., 2024). Chemical methods include double emulsions and nanoemulsions (Zhang et al., 2024).

Although natural pigments offer vast advantages when applied to food, their main impact is on the visual perception of the product, a decisive factor in consumer choice (Aslan Türker and Doğan, 2022; Otálora et al., 2023). They can chemically interact with other ingredients in the formulation, influencing sensory characteristics of flavor and aroma (Mohammadalinejhad et al., 2023; Younesi et al., 2023). In this context, carrying out sensory analysis becomes essential, as it allows us to evaluate whether the colors obtained are visually attractive and meet the expectations of the target consumer.

There is a wide availability of information in the literature on natural pigments, including extensive studies on individual pigment classes (Nabi et al., 2023), extraction, microencapsulation (Miranda et al., 2021; Santos et al., 2021), bioaccessibility (Jin et al., 2023), bioavailability (Soutelino et al., 2024), stability (Molina et al., 2023), biological activity (Feitosa et al., 2023) and food applications (Nabi et al., 2023; Yücetepe et al., 2024). However, there is a notable lack of comprehensive reviews that systematically compare and contrast stability particularities (molecular studies of synthesis and degradation) and acceptance of these pigments by consumers. This gap provides an opportunity for the innovative contribution of this review. Therefore, the objective of this research is to provide a comprehensive and comparative analysis of the main natural pigments, focusing on the genes and transcription factors (TFs) that regulate their synthesis and degradation. Besides, to explore trends in extraction, microencapsulation and application of these pigments in food products, also evaluating their sensory impacts on the food matrix and consumer perception.

Natural pigments as an alternative to replace synthetic dyes

Natural dyes are pigments obtained from plant, mineral and microorganism sources, standing out for the absence of chemical additives in their composition. These pigments have unique properties such as color, stability and physicochemical properties, which make them ideal for specific applications in the food, cosmetic and textile industries (Miranda et al., 2021; Oliveira et al., 2023a, b). Furthermore, they are generally recognized for their non-toxicity and, to a large extent, the absence of allergenic properties, making them a safe and sustainable alternative in various formulations. Among plant pigments, chlorophyll (green color), betalains (red and purple color), anthocyanins (orange, red, violet and blue color) and carotenoids (red, yellow and orange color) stand out due to their bioactive properties and color diversity (Ledari et al., 2024; Manokari et al., 2024; Souza et al., 2024a, b; Żurek et al., 2024).

Synthetic pigments are widely used due to their advantages over natural pigments, such as ease of production, lower cost and greater stability (Molina et al., 2023). However, it is well documented that many of these pigments can have adverse effects on human health (Miranda et al., 2021). Over the past decade, the European Food Safety Authority has extensively analyzed studies linking the use of synthetic food colorings to a range of health problems. Among the reported effects are increased hyperactivity in children (McCann et al., 2007), allergies, toxicity, attention deficit hyperactivity disorder (Amchova et al., 2015), as well as potential carcinogenic properties, among other negative impacts. As a result of these concerns, in recent years there has been a growing interest in natural food colorings, which, in addition to their pigmenting function, offer therapeutic benefits to consumers.

The food industry has adopted natural pigments as an alternative to synthetic dyes due to their safety, health benefits and attractive coloring. These natural compounds can be used to improve the visual appeal of food products, such as sweets, dairy products, beverages and bakery items (Nabi et al., 2023; Yücetepe et al., 2024). Furthermore, pigments such as curcumin, anthocyanins, and betalains are also valued for their medicinal properties, making them potential candidates for functional food applications (Molina et al., 2023; Nabi et al., 2023).

The stability of pigments is a determining factor for their application in the food industry, being directly influenced by environmental variables such as temperature, light, pH and exposure to oxygen (Souza et al., 2024a, b). The degradation of natural pigments can compromise their functional properties, negatively impacting the appearance, quality and acceptance of food products, in addition to limiting their use. In this context, the search for strategies that guarantee the stability of natural pigments has been consolidated as a priority in scientific research, aiming not only to expand but also to improve its applicability in the food industry.

Genes and transcription factors (TFs) that regulate the synthesis and degradation of natural plant pigments

Chlorophyll

Chlorophyll is a fat-soluble green pigment, essential for photosynthesis. Its molecular structure, characterized by a porphyrin ring with a centralized magnesium atom and a phytol chain, gives it the ability to absorb sunlight (Fig. 1). Chlorophyll is the predominant pigment in the initial stages of fruit development, undergoing gradual degradation during ripening and senescence. Understanding the mechanisms that regulate the synthesis and degradation of chlorophyll is essential to elucidate the biochemical processes that govern fruit development and maturation (Gao et al., 2018; Yin et al., 2016; Zhang et al., 2020).

Fig. 1.

Schematic diagram of the synthesis and degradation route of natural plant pigments (NON-YELLOW COLORING 1 (NYC1), ETHYLENE-INSENSITIVE 3 (EIN3), ORESARA1 (ORE1, a TFs of the NAC family), PPH Pheophytinase, NCCs Nonfluorescent chlorophyll catabolite, PDS phytoene desaturase, ZDS zeta-carotene desaturase, LCY-ε lycopene epsilon cyclase, LCY-β lycopene beta-cyclase, GGPP geranyl geranyl pyrophosphate, PSY phytoene synthase, PK pyruvate kinase, FBA fructose-bisphosphate aldolase, CRH-β beta-carotene hydroxylase, CRH-ϵ epsilon carotene hydroxylase, NCEDs 9-cis-epoxycarotenoid dioxygenases, CCDs carotenoid cleavage dioxygenases, CHI chalcone isomerase, CHS chalcone synthase, F3’H flavonoid 3’-hydroxylase, F3H flavanone 3-hydroxylase, LDOX leucoanthocyanidin dioxygenase, DFR dihydroflavone alcohol-4-reductase, UFGT flavonoid-3- O -glucosyltransferase, TFs-MYB MYB family transcription factors, COP CONSTITUTIVE PHOTOMORPHOGENIC, TYR tyrosinases, DOD 4,5-dihydroxy-phenylalanine dioxygenases and GTs glycosyltransferases, L-DOPA L-3,4-dihydroxyphenylalanine, Cyclo-DOPA Cyclo-dihydroxyphenylalanine

Chlorophyll is continually degraded over the development of fruit (Costa et al., 2024). However, as the ripening process begins, chlorophyll degradation intensifies, leading to the loss of the characteristic green color and the exposure of other pigments, such as carotenoids, anthocyanins and betalains. This degradation process involves two main steps: the removal of the phytol tail by the chlorophylase enzymes and the elimination of the magnesium ion, catalyzed by the magnesium chelatase enzyme (Costa et al., 2024; Miranda et al., 2021). However, pheophorbide oxidase is the main enzyme responsible for the degradation of chlorophylls. This enzyme catalyzes the opening of the tetrapyrrolic ring of chlorophyll, an oxidative process that leads to the formation of colorless pigments (Luo et al., 2023; Sato et al., 2009).

Although there is still few studies about the adjustment of chlorophyll synthesis, some of them have shown the action of genes related to degradation of this pigment. Among the genes identified are heme oxygenase 1 (AtHO1), NON-YELLOW COLORING 1 (NYC1) an NADPH-dependent chlorophyll b reductase, ferrochelatase-2, mitochondrial frataxin, the magnesium chelatase subunit and STAY-GREEN protein, all of them acting in chloroplasts. The performance of these genes was observed in studies by Wang et al. (2024a, b), when evaluating physiological changes during the storage period of bitter melon. The authors found that the expression of genes NYC1, and AtHO1 was regulated by chlorophyll metabolism during fruit ripening. NYC1 is dependent on NADPH and plays an important role in the chlorophyll catabolic pathway responsible for the conversion of chlorophyll b to chlorophyll a. In contrast in the amyloplast, was observed overexpression of pheophytin pheophorbide hydrolase and chlorophyll red catabolite reductase, two important genes involved in chlorophyll degradation during kiwi fruit ripening (Actinidia spp.).

Genes encoding chlorophyll catabolic enzymes play a key role in determining fruit color. In bananas, for example, the expression of these genes is modulated by factors such as temperature, influencing the rate of chlorophyll degradation and, consequently, the change from green color to more yellow tones during ripening (Luo et al., 2023). In accord to these authors, at normal ripening temperatures (20 °C), the MaNYC1 enzyme activates the gene that promotes the degradation of chlorophyll, resulting in normal ripening of the banana (Musa acuminata) peel. However, at high temperatures (30 °C), the expression of NYC1 interactive protein 1 (MaNIP1) is induced, leading to proteasomal degradation of MaNYC1 and inhibiting chlorophyll degradation. As a result, the banana peel does not fully ripen and retains a green color. Unlike other fruits, such as tomatoes, mangoes and oranges, in which heat stress promotes the degradation of chlorophyll and changes in skin color, the banana presents an unusual response. While pears and avocados discolor at temperatures above 40 °C, bananas ripen green at temperatures above 24 °C, in conditions that theoretically do not inhibit enzymatic responses. This peculiar response suggests that some fruits have specific molecular mechanisms that regulate chlorophyll catabolism, preventing their normal ripening at high temperatures. Unraveling these mechanisms is fundamental to understanding how thermal stress affects chlorophyll degradation in plants and could contribute to the development of strategies to control fruit ripening (Luo et al., 2023; Wang et al., 2024a, b).

The function of NYC1 has been described in model plants such as Arabidopsis thaliana (Jibran et al., 2015) and rice (Oryza sativa) (Sato et al., 2009), where reduction in expression of the NYC1 gene resulted in a stay green phenotype, characterized by high levels of chlorophyll b. The regulation of NYC1, a central enzyme in chlorophyll degradation, has been the focus of intense studies in recent years, as well as the TFs ETHYLENE-INSENSITIVE 3 (EIN3) and ORESARA1 (ORE1, a TFs of the NAC family) identified as direct transcriptional activators of NYC1 already observed during ethylene-induced leaf senescence (Luo et al., 2023; Sato et al., 2009).

Carotenoids

Carotenoids are isoprenoid compounds characterized by multiple conjugated double bonds in their chemical structures, giving them high reactivity and the ability to absorb light in the visible region of the electromagnetic spectrum (Machado et al., 2025). This absorption results in colors ranging from yellow to red, perceptible to the human eye, although some carotenoids can be colorless, such as phytoene and phytofluene (Galaffu et al., 2015; Jaramillo-Vivanco et al., 2022). These compounds can have cyclic or acyclic structures and are categorized into two main groups, carotenes and xanthophylls. Carotenes, such as lycopene and β-carotene, are characterized by the presence of a linear or cyclic chain at their ends. Xanthophylls, such as violaxanthin, astaxanthin and β-citraurin, are oxygenated derivatives of carotenes and have functional groups in their structures. The accumulation of carotenoids is an important characteristic that not only improves the aesthetic appeal of fruits but also contributes to their nutritional value (Gong et al., 2024).

The carotenoid biosynthetic pathway in plants begins with the condensation of two geranyl geranyl pyrophosphate molecules to form phytoene, catalyzed by the enzyme phytoene synthase (PSY). Phytoene, initially colorless, is desaturated in subsequent steps to form zeta-carotene and finally lycopene (Costa et al., 2024; Machado et al., 2024). While in bacteria this desaturation is mediated by a single enzyme, carotene desaturase, in plants two enzymes are required: phytoene desaturase (PDS) and zeta-carotene desaturase (ZDS). The carotenoid pathway bifurcates at the cyclization of lycopene, which is catalyzed by lycopene cyclases (LCY) to generate alpha-carotene and beta-carotene. The formation of alpha-carotene involves the addition of an epsilon ring to one end of linear lycopene, carried out by the enzyme lycopene epsilon cyclase (LCY-ε), followed by the addition of a beta ring at the other end, mediated by lycopene beta-cyclase (LCY-β). Beta-carotene is formed by the addition of two beta rings at both ends of linear lycopene, also through the action of LCY-β. Flux through these branches therefore depends on the relative activities of the cyclases involved. These cyclic carotenoids are essential for photosynthetic membranes, offering photoprotection and helping to collect light, in addition to giving distinct colors to flowers and fruits, attracting pollinators and seed dispersers (Alquézar et al., 2009; Mendes et al., 2011).

Recent studies sought to understand the role of LCY in ‘Cara Cara’ orange and ‘Star Ruby’ grapefruit being revealed that lycopene accumulation is related to alternative splicing and the expression of specific alleles of β-LCY (Tao et al., 2005).. In red-fleshed grapefruits, the predominance of a non-functional allele of β-LCY2 inhibits the conversion of lycopene into other carotenoids, resulting in an accumulation of this pigment. Furthermore, expression of plastid-specific β-LCY genes was lower in red-fleshed compared to white-fleshed cultivars, suggesting that transcriptional regulation of these alleles is a key mechanism in carotenoid synthesis and lycopene accumulation. Upregulation of upstream genes such as PSY and biosynthetic isoprenoid also contributes to this accumulation (Mendes et al., 2011).

In addition to the regulation of gene expression, the activity of other enzymes, such as PSY and the isoforms of pyruvate kinase (PK) and fructose-bisphosphate aldolase (FBA), enzymes, involved in the final steps of glycolysis and the formation of carotenoid precursors via the plastid methylerythritol phosphate (MEP) pathway, also influence carotenoid production (Alquézar et al., 2009; Mendes et al., 2011; Tao et al., 2005). In pequi (Caryocar brasiliense camb), for example, the increased activity of these enzymes in the final stages of fruiting contributed to a significant accumulation of carotenoids as reported by Costa et al. (2024).

To understand the molecular basis of the diversity of carotenoid accumulation in kiwifruit, the levels of essential carotenoid compounds were measured in several genotypes with different pigmentation phenotypes. Expression analysis of genes involved in carotenoid biosynthesis also identified the LCY-β gene as the main regulator of total carotenoid and beta-carotene accumulation. While expression of the PDS gene was relatively constant across genotypes, genes such as ZDS, beta-carotene hydroxylase (CRH-β), and epsilon carotene hydroxylase (CRH-ϵ) exhibited variation in expression. Furthermore, the LCY-β gene, when functionally tested in bacteria, declared the ability to convert lycopene into beta-carotene and delta-carotene into alpha-carotene. These results indicate that the accumulation of beta-carotene, the predominant carotenoid in several kiwifruit species, is regulated by the expression level of the LCY-β gene (Ampomah-Dwamena et al., 2009). This finding corroborates studies in maize, in which polymorphisms in the LCY-ϵ gene were associated with the accumulation of beta-carotene and xanthophylls derived from this carotene (Harjes et al., 2008).

In studies by Zhao et al. (2021), when investigating the main enzymes related to the accumulation of carotenoids during the ripening of Lycium barbarum (Lb), the expression of PSY showed a strong positive correlation with the levels of zeaxanthin, cryptoxanthin, α-carotene and total carotenoids, suggesting that upregulation of PSY may promote the synthesis and accumulation of these compounds. Furthermore, the expression levels of PDS and ZDS showed a significant and positive correlation with the contents of zeaxanthin, cryptoxanthin and α-carotene, reflecting their role in the conversion of phytoene to lycopene during the ripening of fruit. These results indicate that ZDS contributed to the accumulation of carotenoids during the ripening of L. barbarum, which is consistent with the study by Ma et al. (2018), which showed a similar role of ZDS in mango ripening.

In view of what has been shown, it is possible to observe that most structural genes involved in the carotenoid biosynthetic pathway have been cloned in a wide range of plant species. Comprehensive studies have demonstrated that variations in carotenoid accumulation in fruits are mainly determined by the different transcription levels of carotenogenic genes, and that this differential expression often involves positive or negative regulatory interactions between multiple structural genes (Harjes et al., 2008; Ma et al., 2018).

Few studies address the manipulation of carotenoids, which occurs under the catalysis of carotenoid cleavage oxygenases, which can be broadly categorized into two groups: 9-cis-epoxycarotenoid dioxygenases (NCEDs) and carotenoid cleavage dioxygenases (CCDs) (Luo et al., 2025). NCEDs specifically cleave 9-cis-violaxanthin and 9-cis-neoxanthin, generating xanthoxin, a precursor of ABA, while CCDs negatively correlate with the accumulation of carotenoids, influencing plant color. In Osmanthus fragrans, the expression of genes such as OfCCD1, OfNCED3 and OfCCD4 reduces as carotenoids accumulate. Temperature also affects metabolism: high temperatures inhibit biosynthesis and stimulate degradation, reducing carotenoid accumulation and color intensity; low temperatures favor the accumulation (Luo et al., 2025; Zhang et al., 2022).

Anthocyanins

Anthocyanins constitute an important subgroup of flavonoids that provide color for flowers and fruits and play essential roles in attracting pollinators and seed dispersers. Furthermore, anthocyanins have antioxidant properties, protecting plants against damage caused by abiotic stresses (ultraviolet radiation, drought and extreme temperatures) and biotic stresses (herbivory and pathogen infections). Over the last decades, intensive researches have revealed the complexes genetic and molecular mechanisms regulating the biosynthesis and accumulation of anthocyanins in different plant tissues (Aharoni et al., 2001; Butelli et al., 2012; Kobayashi et al., 2002; Zhao et al., 2023).

The study of anthocyanins began with Mendel’s experiments on the inheritance of flower color in the pea (Pisum sativum) (Zhao et al., 2023). The anthocyanin biosynthesis pathway was established through genetic and biochemical studies in Arabidopsis thaliana and Ipomoea purpurea. Biosynthesis begins with coumaroyl-CoA, produced via the phenylpropanoid pathway, and involves a series of reactions catalyzed by enzymes such as chalcone isomerase (CHI), chalcone synthase (CHS), flavonoid 3’-hydroxylase (F3’H), flavanone 3-hydroxylase (F3H), leucoanthocyanidin dioxygenase (LDOX), dihydroflavone alcohol-4-reductase (DFR) and flavonoid-3- O -glucosyltransferase (UFGT).

MYB family TFs constitute one of the largest families of TFs in plants, playing important roles in diverse biological processes, including plant growth and development. A striking example is its participation in the regulation of anthocyanin biosynthesis in Arabidopsis thaliana; it has also been reported that the TFs-MYB AtPAP1 and AtPAP2 regulate the production of anthocyanin pigments in seeds, imparting a purple color to transgenic tobacco plants (Aharoni et al., 2001). This regulation of anthocyanin biosynthesis by TFs-MYB has also been observed in other species, such as maize, petunia and snapdragon (Antirrhinum majus). Among fruit trees, grapevine stands out for having been extensively studied, with several TFs-MYB involved in regulating grape color (Zifkin et al., 2012).

TFs-MYB are also associated with coloration and anthocyanin accumulation in citrus fruits and other fruit, such as persimmons (Akagi et al., 2010), peaches (Zhao et al., 2023) and Blueberry (Zifkin et al., 2012). It was observed that in the development of grapes and blueberries, anthocyanin synthesis occurs quickly after the beginning of ripening, accompanied by the coordinated activation of the genes responsible for this pathway. In blueberries, the VcUFGT gene accumulates transcripts rapidly, especially in the peel, during ripening. This gene is similar to grape (Vitis vinifera-Vv) VvF3GT, which encodes the enzyme responsible for the glycosylation of anthocyanidins, an essential process for color development. The strong correlation between VcUFGT expression and anthocyanin accumulation suggests that it plays an important role in the glycosylation of anthocyanidins in Highbush blueberry (Vaccinium corymbosum-Vc) (Kobayashi et al., 2002; Zifkin et al., 2012).

Although it is an emerging field, the study of genes and TFs related to the regulation of vegetable color has shown a fundamental role in controlling the processes that determine the pigmentation of these foods. In studies by Li et al. (2012), the authors observed that the MdMYB1 gene, which is allelic to MdMYB10 and MdMYBA, positively regulates anthocyanin biosynthesis and apple (Malus domestica-Md) color under the influence of light. In this case, MdMYB1 expression is induced by light, with transcript and protein levels peaking 48 h after light exposure. However, the increase in fruit color and anthocyanin content occurs later, indicating that MdMYB1 acts early in the anthocyanin biosynthesis pathway.

In sweet cherry (Prunus avium L.- Pav), three PavMYB10 alleles determine fruit skin color: yellow (PavMYB10), blush (homozygous for PavMYB10) and red (presence of at least one intact PavMYB10 allele) (Jin et al., 2016). In strawberries, allelic variation in the MYB10 gene is the main factor controlling natural differences in skin and pulp color (Castillejo et al., 2020). While combined expression patterns and function verification confirmed that CpMYB10 promotes anthocyanin accumulation in Chinese cherry rind, CpMYB4 acts as a minor repressor inhibiting anthocyanin biosynthesis in the fruit (Wang et al., 2024a, b).

Although TFs-MYB are the most evidenced regulators in the literature, the CONSTITUTIVE PHOTOMORPHOGENIC (COP) signaling pathway has also been associated with the regulation of the production of anthocyanin. A study conducted by Wu et al. (2019), when cloning the photoresponse factors COP 1.1 and 1.2 from the peel of the pear ( Pyrus bretschneideri-Pb) to investigate their functions in fruit color, the authors observed that the highest levels of PbCOP1s were observed in leaves, with increased expression during leaf development as they changed from green to red. Overexpression of PbCOP1s in fruit peel resulted in a reduction in anthocyanin synthesis at injection sites. Quantitative PCR analysis of these sites showed that PbCOP1.1 significantly inhibited the expression of genes related to anthocyanin synthesis, such as chalcone isomerase, dihydroflavonol reductase, flavonoid-3-O-glucosyltransferase, basic helix-loop-helix, elongated hypocotyl5 and glutathione S-transferases.

Betalains

Betalains are water-soluble pigments that contain nitrogen in a heterocyclic structure. These pigments are classified into two subtypes: betacyanins, which exhibit red-violet hues, and betaxanthins, which exhibit yellow-orange hues. Betalains are found in 13 families of plants in the order Caryophyllales and are typically recognized by their red color. In addition to their antioxidant properties, betalains have anti-inflammatory and chemopreventive activities, which can promote human health and prevent diseases (Kaur and Ghoshal, 2024; Otálora et al., 2023; Tian et al., 2024).

The biosynthesis of betalains is influenced by several factors, such as light, temperature, nutrition, plant growth regulators and enzymatic activities. Under adverse conditions, such as salinity and water stress, betalains can be accumulated, playing a very important role in defending plants against biotic and abiotic stresses (Qingzhu et al., 2016). This biosynthetic process is catalyzed by a set of enzymes classified into three main groups: tyrosinases (TYR), 4,5-dihydroxy-phenylalanine dioxygenases (DOD) and glycosyltransferases (GTs).

The biosynthesis of betalains occurs in the cytosol, with the amino acid tyrosine as its precursor. This is hydroxylated to form L-3,4-dihydroxyphenylalanine (L-DOPA) in a reaction catalyzed by tyrosinase in the presence of molecular oxygen. L-DOPA, in turn, is oxidized by tyrosinase, generating dopaquinone (Carreón-Hidalgo et al., 2022; Qingzhu et al., 2016; Strack et al., 2003). Cyclo-dihydroxyphenylalanine (Cyclo-DOPA) and betalamic acid are crucial intermediates in the synthesis of betacyanins and betaxanthins. Cyclo-DOPA can be formed either by spontaneous cyclization of dopaquinone or by enzymatic conversion of L-DOPA, catalyzed by an enzyme from the cytochrome P450 family encoded by the CYP76AD1 gene in Beta vulgaris (Polturak et al., 2018; Xie et al., 2020). Betalamic acid, in turn, is obtained from L-DOPA by the action of L-DOPA 4,5-dioxygenase (DODA), which catalyzes the formation of L-DOPA 4,5-dioxygenase (4,5-DOPA), an intermediate that rearranges itself to yield betalamic acid (Carreón-Hidalgo et al., 2022; Qingzhu et al., 2016). Finally, betalamic acid reacts spontaneously with cyclo-DOPA to form betacyanins or with amino acids/amines to form betaxanthins.

Two main betacyanin glycosylation pathways have been proposed. In the first, betanidine, a precursor of betacyanin, is glycosylated by specific glycosyltransferase enzymes, such as 5-O glycosyltransferase (5-GT) or 6-O glycosyltransferase (6-GT), resulting in the formation of betanin and gomphrenin (Polturak et al., 2018). The second pathway suggests that glycosylation occurs at an early stage, with cyclo-DOPA being glycosylated by cyclo-DOPA 5-O-glycosyltransferase before condensation with betalamic acid. In addition to glycosylation, betacyanins such as betanin can undergo acylation with hydroxycinnamic acids, a process catalyzed by acyltransferases (Carreón-Hidalgo et al., 2022; Nabi et al., 2023; Qingzhu et al., 2016; Strack et al., 2003).

In some species, alternative pathways for the biosynthesis of certain betacyanins have been proposed. Betanidine, for example, could be derived from betaxanthins such as portulacaxanthin II (tyrosine-betaxanthin) and dopaxanthin (DOPA-betaxanthin). Other betacyanins, such as 2-decarboxy-betanidin and betaxanthins such as miraxanthin V, can be synthesized from dopamine, obtained by the decarboxylation of L-DOPA catalyzed by DOPA decarboxylase (Carreón-Hidalgo et al., 2022; Polturak et al., 2018; Xie et al., 2020).

Five proteins were identified as essential enzymes in the betalain biosynthesis pathway in red-fleshed pitaya (Hylocereus polyrhizus) polyphenol oxidase, 4,5-DOPA extradiol-like dioxygenase, CYP76AD3 and decarboxylase aromatic amino acid (Hua et al., 2016). The increase in the transcriptional levels of these proteins, observed during the formation of betalains, suggests that they act together in the biosynthesis of these pigments. These results corroborate previous transcriptomic studie with H. polyrhizus, which indicate the participation of these enzymes in the biosynthetic process of betalains (Qingzhu et al., 2016).

Studies have also revealed that the regulation of the betalain biosynthesis pathway is complex and involves the action of several TFs, such as those from the MYB family, which control the expression of genes responsible for encoding biosynthetic enzymes. Strack et al. (2003) identified 70 MYB genes, in addition to genes encoding three other classes of MYB proteins containing multiple MYB repeats in Beta vulgaris. These R2R3-MYB genes were functionally categorized, what led to the identification of a beet-specific clade with an atypical amino acid composition in the R3 domain, putatively responsible for encoding betalain regulators.

Extraction of natural pigments

Pigment extraction generally uses water and organic solvents, but faces limitations of conventional methods, which are time-consuming and inefficient. Traditional techniques such as maceration, percolation, decoction and reflux extraction rely on high temperatures and mechanical forces, resulting in high energy consumption. To overcome these challenges, there are increasing efforts to develop green extraction methods, which are more sustainable and environmentally friendly (Leyva-López et al., 2024; Shridar et al., 2024). Several methods have been studied to maximize pigment extraction, such as ultrasound-assisted extraction (UAE) (Aldana-Heredia et al., 2024), microwave assisted extraction (MAE) (Aktaş et al., 2024), supercritical fluids extraction (SFE) (Mihalcea et al., 2023), enzyme-assisted extraction (EAE) (Miranda et al., 2024), solvent extraction (Pinho et al., 2023), and pressurized liquid extraction (PLE) (Silva et al., 2024). These techniques offer advantages such as lower temperature, greater speed, efficiency and safety, as well as greater yield. However, the complete elimination of solvents is still unfeasible, requiring further research and technological advances to optimize these promising approaches.

Mechanical extraction is a conventional technique that stands out for its safety and sustainability, as it does not use toxic solvents to obtain natural pigments. This process can be conducted with equipment such as blenders (Shamshad et al., 2023), tissue homogenizers (de Lima et al., 2022) and presses (Lukitasari et al., 2024), offering advantages such as shorter extraction time, low environmental and health impact, reduced energy consumption and preservation of the properties of compounds, which guarantees greater integrity and functionality (Miranda et al., 2021).

Mechanical extraction, despite technological advances, continues to be a fundamental technique in the processes of obtaining natural pigments. The versatility of mechanical extraction is evident by the variety of plant matrices and operating conditions used, including different solvents (water, ethanol) and methods (maceration, stirring, controlled heating). In the literature (Table 1) it is possible to observe numerous studies that used this technique to obtain carotenoids (de Lima et al., 2022; Shridar et al., 2024), betalains (Lukitasari et al., 2024; Morales-Huerta et al., 2023), chlorophylls (Jin et al., 2023; Zhang et al., 2023) and anthocyanins (Moshfegh et al., 2025; Raj et al., 2024).

Table 1.

Extraction methods applied to different fruits to extract natural pigments

Extraction methods	Plants	Solvent	Targeted compound	Parameters	Reference
Mechanical extraction	Annatto (Bixa orellana L.)	Water	Carotenoids	–	(Shridar et al., 2024)
	Pumpkin (Cucurbita moschata)	Ethanol	Carotenoids	Stirring at 40 °C for 2 h	(de Lima et al., 2022)
	Beetroot (B. vulgaris L.)	–	Betalains	Physical juicer	(Lukitasari et al., 2024)
	Black carrot (Daucus Carota ssp. sativus)	Ethanol (0.1% HCL)	Anthocyanins	Maceration in a blender at 4 °C	(Raj et al., 2024)
	Spinach (Spinacia oleracea)	Ethanol (95%)	Chlorophyll	Homogenization	(Jin et al., 2023)
	Sour cherry (Prunus cerasus L.)	Ethanol (0.1% HCL)	Anthocyanins	Agitation for 3 h and centrifuge at 8000 g for 30 min	(Moshfegh et al., 2025)
	Beetroot (Beta vulgaris)	–	Betalains	Juice extractor	(Morales-Huerta et al., 2023)
	Hibiscus sabdariffa L	Water	Anthocyanins	Incubation at 91 °C for 12 min	(Leyva-López et al., 2024)
	Black carrot (Daucus carota ssp. sativus)	Ethanol (0.1% HCL)	Anthocyanins	Maceration at 4 °C	(Shamshad et al., 2023)
	Cabernet Sauvignon (Vitis vinífera L.)	Ethanol (50%)	Anthocyanins	Agitation for 2 h at 80 °C and 200 rpm, and centrifugation	(Perković et al., 2024)
Liquid–liquid extraction	Guaraná (Paullinia cupana)	Ethanol	Carotenoids	4 h a 50 °C	(Pinho et al., 2023)
Ultrasound-assisted extraction	Marigold Flower (Tagetes erecta)	Ethanol	Carotenoids	Temperatures (30, 40, 50 °C) and process times of 5, 10, 15 min	(Oo et al., 2024)
	Buriti (Mauritia flexuosa)	Supramolecular solvents (octanoic acid and ethanol)	Carotenoids	Temperature of 50 °C for 15–60 min at 150 W power	(Leite et al., 2021)
	Blackberries (Rubus fruticosus) and elderberries (Sambucus nigra L.)	Ethanol:water (60:40)	Anthocyanins	Time (5, 7.5 and 10 min) and power 250, 325 and 400 W	(Mohammadi et al., 2024)
	Sea Buckthorn (Hippophae rhamnoides)	Ethanol e n-hexane (4:3)	Carotenoids	20 min at 40 °C and 40 kHz	(Roman et al., 2022)
	Beetroot (Beta vulgaris)	Ethanol (50%)	Betalains	Ambient temperature for 30 min at maximum power 700 W and 40 kHz	(Mkhari et al., 2023)
	Blueberry (Vaccinium myrtillus L.)	Ethanol (70%)	Anthocyanins	Incubation at 30 min, 30 °C	(Żurek et al., 2024)
	Haskap Berry (Lonicera caerulea L.)	80% ethanol, 0.5% formic acid, 19.5% water	Anthocyanins	Sonication for 20 min at 35 °C at 20 kHz/1000 W	(Dharmawansa et al., 2024)
	Actinidia arguta	Water	Anthocyanins	Sonication for 31.11 min, an ultrasonic intensity of 30 W/m2	(Teixeira et al., 2023)
	Violet grape	Water	Anthocyanins	Extraction for 6 min at 55 °C with amplitude of 40%	(Romanini et al., 2023)
	Black rice (Oryza sativa L. indica)	Ethanol (0.1% HCL)	Anthocyanins	Power of 500 W and 25 kHz and time of 20 to 60 min	(Devi et al., 2024)
	Chagalapoli (Ardisia compressa K.)	Ethanol (65%)	Anthocyanins	Stir for 30 min on a horizontal shaker at room temperature (~ 25 °C)	(Antonio-Gómez et al., 2023)
	Beta vulgaris L	Water	Betalains	Power 500 W, 20 kHz for 30 min	(Kaur and Ghoshal, 2024)
	Red pitaya (Hylocereus polyrhizus)	Ethanol	Betalains	Power of 275 W and 20 kHz	(Rodrigues Vieira et al., 2024)
	Black carrots	Deep eutectic solvents	Anthocyanins	The lower and upper levels were applied between 10–20 min for the extraction time, between 20–80% for the power to be applied	(Aslan Türker and Doğan, 2022)
Supercritical fluids extraction	Red grapes (Cabernet cultivar)	CO2	Carotenoids	SFE were performed at two different pressure and temperature values, 15 MPa/30 °C for the first extractor (E1) and 45 MPa/45 °C for the second extractor, respectively	(Mihalcea et al., 2023)
Enzyme-assisted extraction	Bacupari (Garcinia brasiliensis)	Ethanol (50%)	Carotenoids	90 units of the enzyme pectinase (Aspergillus niger). The mixture was then placed on a magnetic stirrer for 2 min and left to rest for 150 min in a water bath at a temperature of 35 °C	(Souza et al., 2024a, b)
	Tucumã (Astrocaryum aculeatum)	Acetone (50%)	Carotenoids	90 units of the enzyme pectinase (Aspergillus niger). the mixture was placed on a magnetic stirrer for 2 min and left to rest for 150 min, in a water bath, at a temperature of 35 °C	(Souza et al., 2024a, b)
	Peach palm (Bactris gasipaes)	Ethanol 50%	Carotenoids and anthocyanins	–	(Miranda et al., 2024)
	Bacupari (Garcinia gardneriana)	Ethanol 50%
Microwave assisted extraction	Blackcurrant powder	Methanol (1% HCL)	Anthocyanins	Power 90 W for a duration of 5 min	(Aktaş et al., 2024)
	Plum peels (Prunus domestica)	Ethanol 50%	Anthocyanins	Power 700 W; solvent/solid ratio, 70/1 mL/g; extraction time, 135 s	(Mzoughi et al., 2023)
	Tomato (Solanum lycopersicum)	Ethyl acetate and ethanol	Carotenoids	The coded and actual levels were “-1” (1:10 g:mL, 60 s, 100 W), 0 (1:30 g:mL, 90 s, 200 W) and 1 (1:50 g:mL, 120 s, 300W)	(Aldana-Heredia et al., 2024)
Pressurized liquid extraction	Grape	Water, ethanol (99%) and ethanol (40%)	Anthocyanins	10.35 MPa	(Silva et al., 2024)

°C- temperature, W- watts, Mpa-pressure, min- minute, kHz- frequency, HCL- hydrochloric acid

The UAE uses sound waves to generate mechanical vibrations, promoting expansion and compression cycles that accelerate the extraction of compounds (Mohammadalinejhad et al., 2023). This technique reduces processing time, uses lower solvent/sample ratios and operates at lower temperatures. The increase in mass transfer and efficient rupture of the cell wall, driven by the cavitation phenomenon, are decisive for increasing yield and reducing solvent consumption (Aldana-Heredia et al., 2024). Cavitation also intensifies mass transfer, facilitating the penetration of the solvent into the material and optimizing the process. In the study conducted by Leite et al. (2021), ultrasound proved to be efficient in increasing the yield of total carotenoids in experiments with buriti fruit pulp, when compared to the conventional method. The UAE intensified mass transfer, allowing high yields to be obtained in just 15 min of processing. Corroborating these results, Oro et al. (2023), also reported high levels of carotenoids, highlighting the potential of this technology for the extraction of bioactive compounds. Likewise, UAE proved to be efficient in recovering pigments such as anthocyanins and betalains. Studies have highlighted its effectiveness in increasing the concentration of bioactive compounds, such as cyanidin-3-glucoside and peonidin-3-D-glucoside in fruits and black rice, as well as vitamins such as α-tocopherol and β-carotene, with yields up to five times greater than conventional. It was also efficient in extracting betalains from beetroot bagasse, demonstrating great potential for recovering bioactives from different sources (Devi et al., 2024; Kaur and Ghoshal, 2024; Mohammadalinejhad et al., 2023).

The SFE uses solvents in conditions above the critical point, allowing high selectivity and adjustment of solvation power. Under this perspective, CO₂ is widely used due to its non-toxicity, low cost and moderate critical conditions, ensuring extractions at controlled temperatures, protecting bioactive compounds from thermal damage, light and oxygen (Bhatia et al., 2024; Miranda et al., 2021). The extracts are free of residual solvents, ensuring high purity. To improve the solvation of polar compounds, cosolvents are often added, increasing the efficiency of the method. In a study carried out by Mihalcea et al. (2023), the extraction of carotenoids using supercritical carbon dioxide revealed a strong dependence of the operating conditions on the chemical composition of the extracts. By varying pressure and temperature, researchers obtained distinct phytochemical profiles. The most rigorous conditions, at 45 MPa and 45 °C, provided a substantial increase in the content of polyphenols and carotenoids, especially lycopene and β-carotene, whose concentration doubled compared to the mildest conditions (30 °C and 15 MPa). On the other hand, extracts obtained at lower temperatures and pressures showed a higher concentration of lipophilic compounds, such as fatty acids, tocopherols and phytosterols. These results indicate that supercritical carbon dioxide can be used as a selective solvent to obtain extracts with different functional properties, depending on the process conditions.

The EAE uses enzymes such as cellulase and pectinase to disrupt cellular structures, facilitating the release of natural pigments selectively and efficiently, with less use of solvents and energy. Enzymes act as catalysts, breaking proteins and carbohydrates from cell walls down, increasing yield and reducing extraction time (Miranda et al., 2021). Furthermore, optimized methods can improve the recovery of bioactive compounds such as phenolics and lycopene, especially when combined with mild solvents and low temperatures (Zuorro et al., 2011). Miranda et al. (2024) evaluated the effect of time and enzyme concentration on the extraction of carotenoids from bacupari (Garcinia gardneriana) and peach palm (Bactris gasipaes) pulp, using temperatures of 45 °C and a hydroalcoholic system with 50% ethanol. The authors showed that varying the time and enzyme concentration relationship significantly affected the pigment extraction efficiency. Furthermore, the extraction of pigment from bacupari peel showed a 45% increase in absorbance when using enzymes compared to extraction without enzymes. For peach palm peel, the increase in absorbance was even more significant when the enzyme was used, compared to extraction without enzyme.

In a similar study, using a combination of α-amylase and amyloglucosidase enzymes, researchers obtained an increase in the extraction yield of curcumin from turmeric (Sahne et al., 2017). In another study, the EAE technique was used to extract a carotenoid-rich fraction from red pepper (Capsicum annuum), achieving a highest carotenoid content (Nath et al., 2016). These results demonstrate the potential of enzymes and the EAE technique to extract high-value bioactive compounds efficiently and accurately.

MAE is an innovative extraction technique that can be used independently or in conjunction with other emerging techniques. By applying direct heating to the sample matrix, the microwave promotes a rapid increase in temperature and improves mass and heat transfer (Ashaolu et al., 2024). This facilitates the rupture of the matrix, increasing the release of bioactive compounds. The technique stands out for its efficiency in extracting natural dye, making it a valuable tool for several areas, such as the pharmaceutical, food and cosmetic industries.

MAE has advantages such as reduced process time and less use of solvents. However, the generation of locally elevated temperatures can lead to thermal degradation of bioactive compounds. Therefore, it is important to optimize processing parameters for shorter process times. Aldana-Heredia et al. (2024) optimized the extraction of carotenoids of tomato (Solanum lycopersicum) by MAE and observed that this technique outperformed the conventional method. Among the predominant chemical compounds in the tomato sample, cis-lycopene, 9-cis-lycopene and all-trans-β-carotene stood out, with lycopene presenting the highest percentage among the carotenoids present. However, the authors highlight the importance of considering β-carotene as a possible by-product of the thermal degradation of lycopene, and the influence of thermal conditions on the profile of extracted carotenoids. Anthocyanins were also efficiently extracted from plum (Prunus domestica) peels using the MAE technique. The interaction of the microwave with the plant material caused a significant increase in temperature and intracellular pressure, which facilitated the rupture of the cell wall and the consequent release of pigments (Aldana-Heredia et al., 2024; Mzoughi et al., 2023).

The PLE presents a viable alternative to traditional solvent extraction methods in the preparation of plant extracts. This technique, carried at high temperature (50–200 °C) and pressure (10–15 MPa) out, above the boiling point of the solvent, offers several advantages, such as shorter removal time, lower solvent consumption, greater selectivity and less manipulation of target compounds (Miranda et al., 2021). This process consists of introducing a sample into a container, which is then efficiently subjected to the action of a pressurized and heated solvent, which facilitates its penetration into the vegetable or food matrix, promoting the protection of the target compounds (Rudke et al., 2021).

Although it requires a high initial investment and consumes more energy than other techniques, PLE offers advantages such as greater efficiency and selectivity in extraction, lower solvent consumption, time savings and the possibility of using ecological solvents. This technique finds several applications in the food, pharmaceutical and cosmetic industries, in the extraction of bioactive compounds with antioxidant, anti-inflammatory and antimicrobial properties, among others (Miranda et al., 2021). Silva et al. (2024) reported that the type of solvent applied was extremely important for the recovery of bioactive compounds from grape pomace by PLE. Ninety-nine percent ethanol was the most effective solvent to extract anthocyanins, regardless of the condition of the grape pomace (wet or dry using mild conditions). Temperature proved to be an important variable in the extraction process, in which the higher the temperature, the greater the concentration of compounds in the extract. Therefore, the PLE aligns with the concept of circular economy, promoting the recycling and valorization of waste from the food chain, such as fruit peels, and various by-products from the food industry, transforming them into high-value-added products, such as bioactive extracts (Bhatia et al., 2024).

In short, although the common goal of extraction techniques is to optimize the recovery of natural pigments while maintaining their bioactivity, each method has inherent advantages and limitations. Mechanical extraction stands out for its operational simplicity, low cost and absence of organic solvents, but it often results in lower yields. On the other hand, assisted technologies such as EAE and UAE increase the efficiency and selectivity of the extraction process, although they may require more complex instrumental configurations or enzymatic pre-treatment steps. MAE and PLE extraction provide fast and efficient extractions; however, the potential for thermal degradation of the compounds and the associated energy costs must be carefully evaluated. SFE extraction shows high selectivity and purity, particularly for lipophilic compounds, although the initial investment in equipment is considerable. In general terms, the selection of the extraction method should be based on the nature of the bioactive compound of interest, the physicochemical properties of the raw material and the purpose of the extract obtained. Although emerging techniques have made significant progress in terms of efficiency and sustainability, their implementation on an industrial scale still requires process optimization studies and economic feasibility analyses.

Microencapsulation of natural pigments

The microencapsulation process involves the creation of a protective film layer, often consisting of one and/or several wall materials such as polysaccharides, gums, lipids and proteins. which may be of polymeric origin, responsible for involving and providing protection to the active substance (Souza et al., 2024a, b). Several techniques are used for microencapsulation of natural pigments, which can be used alone or in combination, depending on the characteristics of the pigment and the desired application (Table 2).

Table 2.

Microencapsulation techniques applied to natural plant pigments

Microencapsulation Technique	Plants	Pigment	Wall material	Parameters	Main conclusions of the study	Reference
Spray drying	Annatto (Bixa orellana L.)	Carotenoids	Maltodextrin and gum arabic	Air temperature at inlet and outlet was maintained at 130 °C and 90 °C	↑ Solubility ↓ Moisture	(Shridar et al., 2024)
	Marigold flower (Tagetes erecta)	Carotenoids	Maltodextrin and gum arabic	Inlet air temperature 155 °C and outlet air temperature 90 °C	↑ Bioactive compounds	(Oo et al., 2024)
	Guaraná (Paullinia cupana)	Carotenoids	Gum arabic	Inlet air temperature 100 °C	↑ Stability during storage	(Pinho et al., 2023)
	Guava (Psidium guajava L.)	Carotenoids	Mucilage of Opuntia ficus-indica cladodes and aloe vera leaves	Inlet air temperature 120 °C	↑ Functional potential	(Otálora et al., 2022)
	Renealmia alpinia (Rottb.) Maas	Carotenoids	Maltodextrin and gum arabic	Inlet air temperature of 150 °C and outlet temperature of 98 °C	–	(Jimenez-Gonzalez et al., 2022)
	Sour cherry (Prunus cerasus L.)	Anthocyanins	Maltodextrin and persian gum	Inlet temperature of 170 °C and an outlet temperature of 62 °C	↑ Stability	(Moshfegh et al., 2025)
	Cabernet Sauvignon (Vitis vinifera L.)	Anthocyanins	Goat whey protein	Inlet air temperature was 180 °C	↑ Yield and efficiency ↓ Moisture	(Perković et al., 2024)
	Hibiscus sabdariffa L	Anthocyanins	Porous starch and gum arabic	The inlet air temperature was recorded as 100–180 °C	↑ Controlled release	(Leyva-López et al., 2024)
	Black carrot (Daucus carota ssp. sativus)	Anthocyanins	Maltodextrin and Sericin	Inlet air temperature: 180 °C; outlet temperatures: 75 °C	↑ Efficiency ↑ Essential amino acid content	(Raj et al., 2024)
	Malva sylvestris L	Anthocyanins	Maltodextrin and inulin	Inlet temperature: 120 °C	↑ Controlled release	(Farahani et al., 2024)
	Purple corn (Zea mays L.)	Anthocyanins	Maltodextrin, gum arabic, metilcelulose and skimmed milk powder	Maltodextrin, gum arabic, methylcellulose and skimmed milk powder	–	(Ali et al., 2024)
	Hibiscus sabdariffa L.	Anthocyanins	Maltodextrin and gum arabic	Drying air inlet temperature (130, 145, 160, 175 and 190 °C)	↑ Digestibility	(Toprakçı et al., 2024)
	Pitaya (Stenocereus stellatus)	Betalains	Fructans, Whey Protein Isolate and Modified Starch	Inlet and outlet temperatures of 160 and 85 °C, respectively	–	(Heredia-olea et al., 2024)
	Red pitaya (Hylocereus polyrhizus)	Betalains	Maltodextrin	The inlet and outlet temperatures were 165 and 80 °C, respectively	↑ Stability	(Rodrigues Vieira et al., 2024)
	Pitahaya (Hylocereus spp.)	Betalains	Maltodextrin and mucilage from pitahaya	Inlet air temperature 170 °C	–	(Otálora et al., 2023)
	Garambullo (Myrtillocactus geometrizans)	Betalains	Aloe vera mucilage and maltodextrin	Spray drying temperature of 160 °C	–	(Gómez-Espinoza et al., 2024)
Spray-chilling	Pumpkin (Cucurbita moschata)	Carotenoids	Vegetable fat	Temperature 13 °C	↑ Thermal and oxidative stability	(Lima et al., 2022)
	Hibiscus flower (Hibiscus rosa-sinensis)	Anthocyanins	Fully hydrogenated palm oil and cocoa butter	The temperatures were 67 °C and 77 °C, respectively. Cooling air temperature was approximately -1 °C	↑ Thermal and oxidative stability	(Oliveira et al., 2023a, b)
	Grapes bordo (Vitis labrusca L.)	Anthocyanins	W/O emulsions and polyglycerol polyricinoleate	The temperatures of the samples and the compressed air were 70 °C and 80 °C, respectively, and the cooling air temperature was 1 °C	↑ Crystallity of microparticles	(Figueiredo et al., 2023)
Freeze drying	Tomato (Solanum lycopersicum)	Carotenoids	Maltodextrin, gum arabic whey protein isolate	Temperature of -50 °C for 72 h	↑ Lycopene content ↑ Bioaccessibility	(Aldana-Heredia et al., 2024)
	Grape Cabernet Sauvignon, Cabernet Franc and  Merlot	Anthocyanins	Sodium alginate, gum arabic and gelatin	Temperature of 24–48 h	↑ Bioaccessibility	(Martinović et al., 2024)
	Haskap berry (Lonicera caerulea L.)	Anthocyanins	Maltodextrin and inulin	Freezing at − 20 °C and Freeze-drying (− 45 °C for 72 h)	↑ Efficiency	(Dharmawansa et al., 2024)
	Blackberries (Rubus fruticosus) and elderberries (Sambucus nigra L.)	Anthocyanins	–	Freeze drying for 24 h at − 57 °C	↑ Antioxidant capacity	(Mohammadi et al., 2024)
	Beta vulgaris L.	Betalains	Guar gum, gum arabic and gum tragacanth	Freezing at − 40 °C and freeze-drying at -59 °C	↑ Bioaccessibility	(Kaur and Ghoshal, 2024)
	Beetroot (Beta vulgaris)	Betalains	Maltodextrin	Freeze drying for 48 h	–	(Lukitasari et al., 2024)
	Beetroot (Beta vulgaris)	Betalains	Gum arabic and Maltodextrin	Freezing for 24 h at − 20 °C and freeze-drying for 48 h	↑ Phenolic content	(Mkhari et al., 2023)
Complex coacervation	Black rice (Oryza sativa L. indica)	Anthocyanins	Gelatin and acacia gum	The concentrated extract (20 mL) was mixed with 80 mL soybean oil in the presence of 3% PGPR. Slow addition of citric acid solution (1 M)	–	(Devi et al., 2024)
Ionic gelation	White dragon fruit (Selenicereus undatus)	Anthocyanins	Sodium alginate	2 and 3% solutions of sodium alginate (NaC 6 H 7 O 6) and 75 mM and 100 mM calcium chloride solutions (CaCl 2 2H 2 O, as a complexing agent)	↑ Thermal stability	(Manokari et al., 2024)
Fluidization	Beetroot (Beta vulgaris)	Betalains	Albumin	Drying at 60, 70 and 80 °C	↑ Pigment retention and antioxidant capacity	(Morales-Huerta et al., 2023)
Nanoemulsions	Black rice (BRA)	Anthocyanins	Bovine serum albumin, hyaluronic acid and oxidized hyaluronic acid	Desolvation method	↑ Biocompatibility	(Zhang et al., 2024)
Complex coacervation and vibration nozzle technology	Spinach (Spinacia oleracea)	Chlorophyll	Whey protein isolate and chitosan	The curing time of the microparticles was 1 h in chitosan solution with continuous magnetic stirring at 500 rpm	↑ Thermal and oxidative stability	(Agarry et al., 2022)
Complex coacervation and freeze-drying	Spinach (Spinacia oleracea)	Chlorophyll	Gum arabic and gelatin	Freeze drying at (24 h/-63 °C)	↑ Bioaccessibility	(Jin et al., 2023)
Rotary Side Spray Fluidized Bed	Rice leaves (Oryza sativa)	Chlorophyll	Sodium alginate, sodium caseinate, sodium carboxymethyl cellulose and xanthan gum	The inlet air temperature was maintained at 50 °C and rotation speed of 5 rpm, 3.99 g/min)	↑ Stability during storage	(Yang et al., 2022)
Coacervation and Freeze Drying	Sea buckthorn (Hippophae rhamnoides)	Carotenoids	Alginate, agar and chitosan	Freeze drying at -42 °C for 72 h	↑ Efficiency	(Roman et al., 2022)
Complex coacervation and freeze drying	Red grapes (Cabernet cultivar)	Carotenoids	–	Homogenized at 30,000 rpm for 10 min, followed by dropping the pH to 3.75, freeze-dried at -42 °C for 48 h	–	(Mihalcea et al., 2023)
Ionotropic gelation and freeze drying	Blueberry (Vaccinium myrtillus L.)	Anthocyanins	Sodium Alginate, Pectin Whey Protein Isolate	Complexation for 30 min in 5% CaCl2	↑ Efficiency	(Żurek et al., 2024)
Ionic gelation and double emulsion	Fresh purple basil (Ocimum basilicum L.)	Anthocyanins	Sodium alginate and Carrageenan	voltage 6 kV; current 1 μA; feeding rate 1.2 mL/h; the distance between the tip of the syringe (21G) and the collection bath was set at 10 cm	–	(Ozcan et al., 2024)

°C- temperature, min- minute ↑- biggest, and ↓- smallest, h- hours

Various materials have been widely used in the microencapsulation process and are responsible for enveloping the substance of interest and forming the microparticles. These materials can come from natural, synthetic or semi-synthetic sources, including polymers, hydrophilic or hydrophobic substances or combinations of both (Souza et al., 2025a, b). It is essential that the wall material is compatible with the encapsulated compound, i.e. that it does not react with it and that it has desirable technological characteristics, such as good drying properties, low cost, easy availability, low viscosity and reduced hygroscopicity. It must also be stable and able to offer efficient protection to the encapsulated active ingredient (Souza et al., 2024a, b). The most common carriers used in spray drying include carbohydrates such as maltodextrin and gum arabic, as well as mucilage, whey protein, starch, inulin, gelatine and sodium alginate.

Spray drying

In recent years, microencapsulation methods have been consolidated as promising strategies for stabilizing natural pigments, using different techniques (Souza et al., 2025a, b). Among the physical methods, spray drying stands out as one of the most traditional and widely used techniques in the food industry, due to its efficiency, low operating costs and wide availability of equipment. The principle of the process consists of dispersing the active compound in an aqueous solution containing the wall material, which is then atomized in a drying chamber. Initially, the core material is homogenized with the biopolymers, which must have good water solubility to allow the formation of a stable emulsion. This emulsion is then atomized into small droplets, which are quickly dried by contact with hot air in the drying chamber.

In this context, Shridar et al. (2024) investigated the production of microcapsules of annatto (Bixa orellana L.) extract rich in carotenoids by spray drying, using gum arabic and maltodextrin as carrier agents. The authors reported that the formulations containing maltodextrin showed high encapsulation efficiency (86.28%), high process yield (195.75 g/500 mL), low water activity (0.65) and low moisture content (4.07%). The microcapsules also showed good homogeneity and high solubility (> 97%). Similar results were obtained by Oo et al. (2024) and Souza et al. (2024a, b) when they microencapsulated carotenoids extracted from marigold flower (Tagetes erecta) and bacupari (Garcinia brasiliensis), respectively, using maltodextrin and gum arabic. Both studies reported high retention of bioactive compounds and solubility of between 96.36% and 97.98%, reinforcing that solubility is a crucial factor for the quality of reconstitutable food products. This behavior is attributed to the high water solubility of carbohydrate-based polymers, which favors the dispersion and dissolution of the encapsulated molecules.

Furthermore, microencapsulation by spray drying has been associated with greater stability of bioactive compounds. Moshfegh et al. (2025), for example, reported on the stability of microencapsulated anthocyanins from sour cherry (Prunus cerasus L.), observing that after 28 days of storage, exposure to light did not significantly affect the anthocyanin content when maltodextrin was used as the wall material. Similarly, Rodrigues Vieira et al. (2024) showed that at the end of 90 days of storage in light-protected conditions, the microencapsulated extract of red pitaya (Hylocereus polyrhizus) pulp showed only a slight reduction in betalain levels, demonstrating the effectiveness of the technique in preserving the stability of the pigments over time.

Spray-chilling

The spray chilling method has been widely used in the microencapsulation of bioactive compounds due to its operational advantages, such as low processing costs, feasibility of application on an industrial scale, continuous process, absence of organic solvents and use of reduced temperatures. The principle of this technique is based on the solidification of an atomized fluid in a cooling chamber, usually with ambient or refrigerated air. Because it operates under mild thermal conditions, spray chilling is considered a promising approach for preserving thermosensitive compounds.

From this perspective, Lima et al. (2022) investigated the microencapsulation of carotenoids extracted from pumpkin (Cucurbita moschata) by-products using the spray chilling process and plant fat as a carrier material. The microparticles obtained showed high encapsulation efficiency (95.2%), high retention of carotenoids during storage (60.8–89.7%) and significant release of the compounds in the simulated intestinal phase (32.6%).

Similar results were observed by Oliveira et al. (2023a, b), who evaluated the microencapsulation of hibiscus flower (Hibiscus rosa-sinensis) anthocyanins using the same technique. Despite the low retention of the pigments under conditions of accelerated stability (temperature of 35 °C and exposure to light), attributed to the sensitivity of the anthocyanins, the in vitro gastrointestinal digestion tests showed that the microparticles promoted greater bioaccessibility of the compounds. This is due to the protective barrier provided by the wall materials, which enabled a controlled and continuous release of the anthocyanins into the simulated gastric fluid, unlike the pure extract.

Complementing these findings, Figueiredo et al. (2023) confirmed the effectiveness of the technique by producing lipid microparticles containing anthocyanins from Grapes Bordo (Vitis labrusca L.) skin extract, using mixtures of fully hydrogenated palm oil (FHPO) and palm oil (PO) as carriers. All treatments conferred protection to the anthocyanins in the gastric phase, favoring greater release in the intestinal phase, especially as the concentration of PO increased. These results suggest that spray cooling is an effective alternative for producing microparticles with biological and technofunctional properties.

Freeze drying

Freeze-drying is a method that combines low temperatures and reduced pressures, or even vacuum, and is widely used for the microencapsulation of heat-sensitive compounds as well as living cells. Its basic principle consists of dehydration under conditions of low temperature and pressure, which allows the integrity of the encapsulated compounds to be preserved. In the food industry, freeze-drying has been adopted as an alternative to methodologies that use heat for encapsulation, since the products obtained by this method keep their nutritional characteristics preserved due to the absence of thermal exposure.

In a study conducted by Aldana-Haredia et al. (2024), when microencapsulating tomato by-products (Solanum lycopersicum) using gum arabic, maltodextrin and whey proteins by the freeze-drying method, it was observed that the technique used proved to be a valid method for encapsulation, with significantly high bioaccessibility values (27.68% and 25.10%). In this way, freeze-drying demonstrated to be a valuable strategy for the preservation and bioavailability of important components present in food by-products. As reported by Martinović et al. (2024) who demonstrated the efficiency of microencapsulation to increase the bioaccessibility of phenolic compounds from grape pomace extracts. In their studies, the technique of microencapsulating anthocyanins with sodium alginate, alone or in combination with gum arabic and gelatine, promoted the conversion of the crystalline structure of grape pomace extracts to an amorphous form, which positively impacted the release and bioaccessibility index of phenolic compounds during the intestinal phase of simulated digestion.

Dharmawansa et al. (2024) also verified the efficiency of the freeze-drying method to microencapsulate bioactive compounds, where anthocyanins extracted from haskap nerry (Lonicera caerulea L.) were efficiently microencapsulated by freeze-drying using a mixture of maltodextrin and inulin (3:1). The microcapsules obtained showed encapsulation efficiency of up to 60% and anthocyanin recovery of around 89%, demonstrating suitable structural properties for functional application and the potential to protect anthocyanins from degradation.

The technique has also been successfully used in the microencapsulation of betalains. Kaur and Ghoshal (2024), for example, demonstrated that encapsulation of beetroot (Beta vulgaris) extract with guar gum resulted in greater bioaccessibility of the bioactive constituents and showed superior efficacy and stability for betalains under accelerated storage conditions. Corroborating the effectiveness of the technique in protecting these pigments, Lukitasari et al. (2024) carried a stability study out for the four main microencapsulated betalains (vulgaxanthin I, betanin, isobetanin and neobetanin). Their results indicated that these pigments showed relative stability even under conditions of high acidity, after three days of storage, indicating high efficiency of microencapsulation of sensitive compounds by this method.

Complex coacervation

Coacervation is a chemical encapsulation technique that differs from more traditional encapsulation methods in that it does not require the use of bulky equipment to form microparticles (Devi et al., 2024). The basic mechanism of this method consists of three distinct stages: the formation of immiscible phases, the deposition of wall material around the target compound and, finally, shrinkage and solidification (Roman et al., 2022). This method has been widely used to encapsulate different natural pigments, either alone or in combination with other techniques, with the aim of improving the stability and delivery of these compounds. A notable example is the work of Agarry et al. (2022), who used complex coacervation and a vibrating nozzle to encapsulate Spinach (Spinacia oleracea) chlorophyll. Using whey protein isolate and chitosan as carriers, the authors obtained chlorophyll particles with an acceptable green color and high encapsulation efficiency (94.9–96.1%). In addition, these particles showed greater stability to light and pH compared to unencapsulated chlorophyll.

Similarly, the combination of complex coacervation and lyophilization produced stable chlorophyll micropoarticles, as reported by Jin et al. (2023). The formulations that included pectin as an encapsulating agent exhibited improved recovery rates, as well as a better bioaccessibility index. In a similar way, Mihalcea et al. (2023) used emulsification, complex coacervation and lyophilization to microencapsulate red grape extracts (Cabernet cultivar). The powders obtained showed a good retention rate of polyphenols and flavonoids and also showed greater stability of the bioactive compounds during in vitro digestion.

Other methods

The literature demonstrates a wide range of microencapsulation techniques for natural pigments, in addition to the approaches already discussed. Examples include ionic gelation in the microencapsulation of anthocyanins (Manokari et al., 2024), fluidization for betalains (Morales-Huerta et al., 2023) and nanoemulsion microencapsulation of anthocyanins (Zhang et al., 2024). In addition, the combination of new methods, such as ionic gelation and double emulsion, ionotropic gelation and freeze drying, and rotary side spray fluidized bed, has generated satisfactory results in compound retention, stability and bioaccessibility, indicating great potential for success in food applications (Table 2) (Yang et al., 2022; Ozcan et al., 2024; Żurek et al., 2024).

The effectiveness and versatility of microencapsulation techniques and their combinations, as demonstrated, depend critically on strict control of their parameters. Thus, each of the mentioned techniques makes it possible to modulate specific characteristics of microparticles, such as size, morphology, controlled release capacity and resistance to oxidation. Obtaining microparticles with specific characteristics requires precise control of various process parameters, such as the inlet and outlet air temperatures of the spray-drier, the residence time and rotation speed of the fluidized bed, and the concentration of polymers in the feeding solution. In electrostatic processes, the voltage applied are critical variables that influence morphology, particle size and encapsulation efficiency. In addition, precise control of temperature and pressure during freezing and freeze-drying is essential to ensure the stability and maintenance of the encapsulated material’s properties (Table 3).

Table 3.

Applications of natural plant pigments in foods

Pigment	Plants	Food matrix	Main conclusions of the study	Reference
Anthocyanins	Illawarra Plum	Yogurt	Stable pink color	(McCullum et al., 2024)
	Cornelian cherry fruits (Cornus mas L.), red cabbage (Brassica oleracea L. var. capitata L. f. rubra, var. Garance), chokeberry t (Aronia melanocarpa)	Bread	Higher content of anthocyanins and antioxidant activity compared to wheat bread	(Czubaszek et al., 2023)
	Juçara palm fruit (Euterpe edulis Mart.)	Fermented milk	Better product color stability	(Silva Crozatti et al., 2023)
	Black rice (Oryza sativa L. indica)	Noodles	It increased the hardness and elasticity of cold steamed noodles, delayed their retrogradation, promoted resistant starch content and conferred antioxidant capacity	(Zheng et al., 2022)
	Chagalapoli (Ardisia compressa K.)	Isotonic beverage	The pigments proved to be suitable for application in isotonic drinks	(Antonio-Gómez et al., 2023)
	Purple basil leaf	Jelly candies	Damaged the color and appearance of the jellies	(Ozcan et al., 2024)
	Blackberries (Rubus fruticosus) and elderberries (Sambucus nigra L.)	Gum candy	Higher content of phenolic compounds and antioxidants	(Mohammadi et al., 2024)
	Poppy-pollen (Papaver bracteatum)		The color indices and sensory perception of fortified gummy candies have been improved	(Sarabandi et al., 2023)
	Violet grape	Gelatin	The encapsulating matrix retained the color for 30 days	(Romanini et al., 2023)
	Wine (Vitis vinífera L.) and blueberry (Vaccinium corymbosum)	Chocolate	Wine powder reduced the predominance of cocoa butter in white chocolates	(Gaona et al., 2024)
	Black carrot (Daucus carota ssp. sativus)	Ice cream	Improved the sensory characteristics of ice cream	(Shamshad et al., 2023)
	Roselle (Hibiscus sabdariffa)	Gummy candy	Gummies obtained using 6% concentration of the above powder gave the highest overall sensory scores	(Younesi et al., 2023)
	Prickly pear (Opuntia ficus-indica)		Good visual acceptance of the encapsulated natural color pigment incorporated in the gums	(Mehta et al., 2024)
	Red cabbage (Brassica oleracea L.)	Aluar	Successfully increased your overall quality	(Sakulnarmrat et al., 2021)
	Hibiscus sabdariffa L.	Sunflower oil	Increased phenolic content and antioxidant capacity	(Toprakçı et al., 2024)
		Corn oil	Corn oil increased phenolic content
Carotenoids	Bacupari (Garcinia brasiliensis)	Margarine	The color tone of the margarine, added with pigmented microcapsules, did not change significantly over the storage time	(Souza et al., 2024a, b)
	Guaraná (Paullinia cupana)	Oatmeal paste	Increased the onset and peak temperature of starch, and decreased its enthalpy	(Pinho et al., 2023)
	Renealmia alpinia (Rottb.) Maas	Yogurt	Yellow color with non-significant changes in antioxidant activity and acceptable sensory attributes up to 28 days of storage	(Jimenez-Gonzalez et al., 2022)
	Guava (Psidium guajava L.)		The color characteristics were maintained during the storage period	(Otálora et al., 2022)
	Sea buckthorn (Hippophae rhamnoides)	Mayonnaise	Improved the Carotenoid content and antioxidant activity of sauces	(Roman et al., 2022)
	Annatto seeds (Bixa orellana L.)	Isotonic tangerine soft drink	The stability of the drink during storage under accelerated conditions (heat and light), and the half-life was more significant than when unencapsulated norbixin was used	(Tupuna-Yerovi et al., 2021)
Betalains	Beetroot (Beta vulgaris L.)	Yogurt	The inclusion of powders obtained from yogurt led to a reduction in the syneresis value	(Yousefi et al., 2022)
	Pitahaya (Hylocereus megalanthus)	Gummy candy	It favored the total dietary fiber content, as well as the gumminess and chewiness of the food matrix	(Otálora et al., 2023)

Applications of pigmented microcapsules in food

To organize the discussion on the applications of microencapsulated pigments in food systems, the studies were grouped into four main categories: dairy products, bakery products, confectionery products and oils/beverages. This division was based on the similarities between the food matrices and the frequency of use reported in scientific literature.

Dairy products

The fortification of dairy products with bioactive compounds represents a promising approach to promoting the health and well-being of consumers. By adding these compounds to these foods, it is possible to improve the nutritional profile of the products and give them functional properties that can benefit intestinal health and the immune system. The literature presents several studies that demonstrate the application of natural pigments and elucidate their main implications (Fig. 2).

Fig. 2.

Applications of natural pigments in food matrices

The incorporation of freeze-dried Illawarra plum anthocyanin into yogurt formulations resulted in a stable pink color, attributed to the presence of anthocyanins, with a high concentration of phenolics and greater antioxidant activity (McCullum et al., 2024). Furthermore, plum powder improved the physical characteristics of Greek yogurt without compromising its quality during 28 days of refrigerated storage. Similar results were found in the application of microcapsules rich in anthocyanins from juçara (Euterpe edulis Martius) in fermented milk (Silva Crozatti et al., 2023). In chocolates, the inclusion of mycoencapsulated anthocyanins from Vitis vinifera L. cv and blueberry, (Vaccinium corymbosum) provided a more complex and balanced sensory profile, mitigating the predominance of cocoa butter (Gaona et al., 2024). Likewise, the addition of anthocyanins extracted from black carrots in ice cream formulations significantly improved the sensory characteristics of the product, making it more attractive to consumers (Shamshad et al., 2023). However, during storage, it was revealed that there was a slight decline in the concentration of constituents due to exposure to oxygen and interaction with other food ingredients.

Different sources of carotenoids have been explored for coloring dairy products. The addition of bacupari (Garcinia brasiliensis) microcapsules to margarine proved to be effective in maintaining the desired shade during storage (Souza et al., 2024a, b). In the study carried out by Otálora et al. (2022), it was demonstrated that the incorporation of microencapsulated guava pulp in Opuntia ficus-indica mucilage or Aloe vera in Greek yogurt resulted in a product with higher lycopene content (352–346 mg/kg), antioxidant capacity and dietary fiber content (8–12%). Furthermore, the yogurt presented a natural and stable color throughout the storage period, compared to commercial yogurt containing synthetic sunset yellow coloring. It was also demonstrated that the use of natural sea buckthorn carotenoids in mayonnaise provided significant improvements in its properties, such as color, texture and antioxidant activity, without compromising sensory acceptability (Roman et al., 2022).

Bakery products

In baking, the incorporation of microencapsulated extracts from plants such as carnelian cherry, red cabbage and chokeberry in bread formulations resulted in a significant increase in the anthocyanin content (0.46 mg/g) and antioxidant capacity of the final products, without compromising their sensory acceptability (Czubaszek et al., 2023). During simulated digestion, a decrease in the concentration of anthocyanins was noted, especially after the intestinal digestion phase. Acylated anthocyanins from red cabbage showed greater digestive stability than carnelian anthocyanins from cherry and chokeberry. In a similar study, the incorporation of pigmented red cabbage microcapsules into aluar proved to be an effective strategy to improve the quality and stability of this food. According to Sakulnarmrat et al. (2021), the presence of anthocyanins present in red cabbage contributed to the increase in antioxidant capacity, delaying lipid oxidation and prolonging the shelf life of the product. The combination of pasta, black rice and chelating agent resulted in a product with improved functional and nutritional properties. According to Zheng et al. (2022), the addition of black rice and chelator delayed starch retrogradation, resulting in steamed noodles with greater elasticity and less hardening after cooling. Furthermore, noodles naturally colored by black rice anthocyanins showed an increase in resistant starch content and antioxidant capacity, giving them functional properties and potential health benefits. The presence of the chelating agent contributed to the stability of anthocyanins and to the formation of complexes with the phenolic compounds of black rice, intensifying the color and activity of the final antioxidant product.

Confectionery products

In confectionery products, in addition to their aesthetic function, pigments also contribute to the characteristic flavor and aroma of many foods and are also capable of providing greater antioxidant capacity. This characteristic offers an important advantage in terms of extending the shelf life of food products and preserving their nutritional value, preventing deterioration due to oxidation.

Mohammadi et al. (2024) evaluated the potential of blackberry and elderberry extracts in fortifying gummy bears. The results indicated a significant increase in the phenolic content (2.58–2.82 mg GAE/30 g), antioxidant activity and anthocyanins in gummy candies formulated with natural extracts, highlighting the potential of these fruit in promoting health. In recent studies, the use of pigmented microcapsules, anthocyanins and betalains (betaxanthin) from Iranian poppy and prickly pear flowers in gummy candy formulations has shown to be a promising alternative. Younesi et al. (2023) observed that the addition of pigmented microcapsules at concentrations of 4–6% provided stable coloring, high sensorial acceptance, higher levels of total dietary fiber, as well as improved the gumminess and chewiness of the food matrix. Sarabandi et al. (2023) and Mehta et al. (2024) corroborated these results, showing that natural pigments contributed to intensifying the color and improving the sensory perception of gummy candy, without causing negative changes in the appearance of the product. On the other hand, Ozcan et al. (2024) reported undesirable changes in the appearance of jelly candies fortified with purple basil leaf emulgel spheres, indicating that there was an interaction between the pigment and the components of the formulation, significantly influencing the stability of the pigment and in the characteristics of the final product.

Oils and beverages

The application of natural dyes in beverages, for example, offers a series of advantages, such as the possibility of giving attractive colors to products, in addition to providing health benefits, since many of these dyes have antioxidant and anti-inflammatory properties. In this context, Antonio-Gómez et al. (2023) investigated the influence of microencapsulation on the stability of chagalapoli anthocyanins in isotonic beverage, subjected to different temperatures. The results demonstrated that, at 4 °C, there was no significant difference in the stability of anthocyanins, regardless of the form of addition. However, at 25 °C, microencapsulated anthocyanins showed greater degradation compared to free anthocyanins, during beverage storage. In contrast, the addition of norbixin microcapsules to tangerine isotonic soft drinks gave to it its characteristic orange hue, without exceeding regulatory limits (Tupuna-Yerovi et al., 2020). The microencapsulation of norbixin significantly increased its stability, with a half-life approximately 13 times longer when compared to the free form, when subjected to accelerated storage conditions.

In addition to their application in isotonic drinks, anthocyanins have also been explored in other food matrices. Toprakçı et al. (2024) demonstrated that the addition of hibiscus microparticles to sunflower and corn vegetable oils promoted a considerable enrichment in phenolic compounds, mainly anthocyanins, and consequently, a significant increase in the antioxidant capacity and phenolic content (0.072–0.084 mg GAE/g) of these oils, in addition to an improvement in around 5% in oxidative stability, highlighting the potential of anthocyanins as antioxidants in lipid matrices.

Functional and biological properties of natural pigments

Faced with the growing aggravation in the population’s state of health, influenced by various biotic and abiotic factors, recent studies have highlighted the potential of plant sources as reservoirs of bioactive compounds with beneficial properties for human health (Monteiro et al., 2025a, b). Among these compounds, the natural pigments present in plants are widely recognized not only for conferring a characteristic color to fruits, vegetables and other plants, but also for performing relevant biological functions (Souza et al., 2025a, b; Monteiro et al., 2025a, b). These pigments have been extensively studied and show significant antioxidant activity, as well as anti-inflammatory, anti-cancer, anti-mutagenic and chemopreventive effects, proven in in vitro studies, animal models and clinical trials. Compounds such as carotenoids, anthocyanins and betalains have also stood out for their anti-diabetic properties, making them promising candidates for the formulation of functional foods aimed at preventing and controlling metabolic diseases (Enache et al., 2020; Feitosa et al., 2023).

Several studies have highlighted the powerful antioxidant activity of carotenoids, which can prevent oxidative damage to DNA, proteins and lipids, as well as acting as antigenotoxic agents (Carneiro et al., 2017). Additionally, these compounds also demonstrate neuroprotective effects, attenuating memory loss and oxidative stress in brain tissues, and contribute to maintaining cell viability, preventing necrosis and apoptosis processes (Jantsch et al., 2023). In addition, carotenoids have a positive influence on the immune system, promoting endogenous antioxidant responses and modulating defense mechanisms against inflammatory and infectious processes (Bonadiman et al., 2021). These properties prove their potential as bioactive ingredients in nutraceutical formulations and functional foods aimed at preventing chronic and degenerative diseases.

Anthocyanins, particularly in their microencapsulated form, have revealed a wide range of beneficial biological properties. Numerous studies have shown their outstanding antioxidant activity (Oo et al., 2024; Figueiredo et al., 2023; Oliveira et al., 2023a, b), often associated with promoting cardiovascular health. In addition, they exhibit antidiabetic effects by inhibiting the enzymes α-amylase and α-glucosidase, contributing to glycemic control (Enache et al., 2020). Other reported functional properties include anti-obesity, hypocholesterolemic, anticancer, anti-inflammatory, bacteriostatic, neuroprotective and positive modulation of the intestinal microbiota (Feitosa et al., 2023). Although these effects are well documented in in vitro and in vivo studies, more studies are still needed to confirm their effectiveness.

Betalains, in turn, have shown remarkable antioxidant activity in different biological models (Carreón-Hidalgo et al., 2022). In HT-29 human cells, pretreatment with betalains significantly reduced oxidative damage to DNA induced by hydrogen peroxide, suggesting a potential cytoprotective effect (Esatbeyoglu et al., 2014). Additional evidence suggests that these pigments inhibit lipid peroxidation, neutralize lipoperoxidases and prevent the breakdown of heme, playing an important role in protecting gastrointestinal cells during digestion (Gengatharan et al., 2015). In vivo tests showed that oral administration of betalains in irradiated mice dose-dependently increased the activity of antioxidant enzymes, such as superoxide dismutase and glutathione peroxidase, in organs such as the liver, spleen and kidney (Wroblewska Juskiewicz & Wiczkowski, 2011). Human studies have also found an increase in systemic antioxidant capacity after consuming juice rich in betalains. This evidence reinforces the ability of betalains to modulate the cellular redox balance, making them promising candidates in the formulation of functional foods aimed at preventing diseases associated with oxidative stress (Carreón-Hidalgo et al., 2022).

The evidence presented corroborates the promising role of these compounds as bioactive ingredients in the formulation of functional foods and nutraceuticals aimed at preventing and controlling chronic and degenerative diseases, as well as conditions associated with oxidative stress. Although the results obtained so far are encouraging, future research, especially in food systems and with a focus on bioavailability and long-term effects in humans, is essential to consolidate the safe and effective application of these compounds in promoting health and improving quality of life.

Sensory impacts of natural pigments on consumer perception

Sensory analysis is essential to evaluate the acceptability and quality of foods, adapting methodologies and scales to the objectives of each study. Different methods, such as hedonic tests, temporal dominance of sensations (TDS) and quantitative descriptive analysis, are used with trained and untrained panels, highlighting their flexibility in evaluating pigments and food products (Table 4).

Table 4.

Sensory impacts of the application of natural pigments in foods on consumer perception

Sensory test	Pigment	Food matrix	Number of panelists	Scale	Attributes analyzed	Reference
Acceptance Test	Chlorophyll	Nooodles	Ten trained members including 5 women and 5 men aged 20 to 24	with the total score of 100 points	Color, surface, palatability, toughness, stickiness, smoothness and taste	(Zhang et al., 2023)
Hedonic scale	Anthocyanins	Gummies	Fifty participants (18–55 years; 26 men and 24 women) participated	1-disliked extremely, to 9-liked extremely	Texture, taste, colour, and overall impression	(Mohammadi et al., 2024)
Hedonic scale	Anthocyanins	Jelly candies	20 equal gender panelists	Very dislike, dislike, and very like	Appearance, texture, color, aroma, chewiness, and overall acceptance	(Ozcan et al., 2024)
Temporal Dominance of Sensations (TDS) and hedonic scale	Anthocyanins	Chocolate	43 painelist	1-dislike extremely to 9-like extremely	Sourness, bitterness, sweetness, astringent, melting, fruitiness, cocoa, grainy, fatty, unctuous, wine-like, cocoa butter and preference	(Gaona et al., 2024)
Hedonic scale	Anthocyanins	Gummy candy	18 panelists of equal genders	1-Very dislike to 5-very like	Color, chewiness, adhesiveness, hardness, taste and overall acceptance	(Younesi et al., 2023)
Hedonic scale	Carotenoids	Mayonnaise	20 untrained tasters with ages ranging from 25 to 55 years (80% women and 20% men)	-	Color, aroma, taste, consistency, texture, smell, aftertaste, spreadability, and acceptability	(Roman et al., 2022)

In your study, Zhang et al. (2023) carried out a sensory analysis of noodles with added chlorophyll-rich microcapsules, using a panel of ten trained consumers. The evaluation, carried out on a 100-point scale, considered attributes such as color, surface, palatability, toughness, stickiness, smoothness and taste. Color, a fundamental aspect of consumer preference, was significantly influenced by the addition of chlorophyll microcapsules. Concentrations between 0.1% and 0.5% gave the noodles an attractive green hue, associated by many consumers with healthy and nutritious products. However, the 1.0% addition resulted in an excessively dark green color, which was considered unpleasant by some tasters. Regarding palatability and flavor, the formulations with chlorophyll microcapsules presented higher scores than the control sample, indicating an improvement in the overall sensorial quality of the product. The noodles with 0.5% microcapsules obtained the best evaluation, suggesting that this concentration represents an excellent balance between visual perception and flavor, resulting in a more attractive product for consumers.

In a similar study, Mohammadi et al. (2024) carried out a sensory evaluation of gummies with the addition of anthocyanins from blackberry (BB) and elderberry (EB) extracts, using a 9-point hedonic scale and 50 participants to evaluate texture, taste, colour, and overall impression. Although the gummies with added anthocyanins (BB and EB) had slightly lower color scores than the commercial control, there were no significant differences between the anthocyanin samples. Regarding flavor, texture and general acceptability, no statistical differences were observed between the tested formulations and the control, indicating that the addition of anthocyanins did not compromise the sensorial acceptance of the product. Taster ratings ranged from "I liked it slightly" to "I liked it a lot", with all formulations exceeding the 70% acceptability threshold. Thus, all gum formulations achieved satisfactory sensory acceptance.

Younesi et al. (2023) in turn, evaluated the color, chewiness, adhesiveness, hardness, taste and overall acceptance of gummy candies fortified with microcapsules rich in Roselle anthocyanins (Hibiscus sabdariffa), using a 5-point hedonic scale and 18 panelists. The color of the gummies was significantly influenced by the concentration of the microcapsules, with the formulation with 4% powder showing the most intense and attractive red color. Concentrations greater than or less than 4% resulted in a dull red, less desirable shade. The hardness, gumminess and chewinessof the gummy candies were not significantly affected by the different concentrations of microcapsules. Regarding flavor, the formulation with 6% powder obtained the highest score, without presenting astringency or other unpleasant flavors. In a recent study carried out by Ozcan et al. (2024), Jelly candies were fortified with purple basil leaf extract rich in free anthocyanins (PBLE) and with emulgel beads containing PBLE. Using a hedonic scale with 20 panelists, the authors evaluated the Appearance, texture, color, aroma, chewiness, and overall acceptance of jellies with anthocyanins. Jelly samples enriched with emulgel spheres beads greater hardness, stickiness, flexibility and chewiness compared to samples with free PBLE. Although the color and appearance of the jellies fortified with encapsulated PBLE were slightly affected, these samples obtained the highest sensory acceptance scores.

Dynamic sensory analysis, such as TDS, is ideal for evaluating products with phenolic compounds due to persistent sensations such as bitterness and astringency. TDS allows you to identify the sequence of dominant sensations during consumption, providing a detailed view of sensory evolution over time. In a study conducted by Gaona et al. (2024), the dynamic sensory profile of chocolates enriched with red wine and anthocyanin-rich blueberry microcapsules was evaluated using the TDS and a 9-point hedonic scale with 43 consumers. TDS analysis revealed that the sensation of cocoa butter was predominant when tasting the control samples. However, the addition of red wine and blueberry microcapsules promoted a significant change in the sensorial profile, with a reduction in the dominance of cocoa butter and the emergence of new sensations, such as wine, fruity and sweet, especially at the beginning of the tasting. The sweet sensation, in turn, remained dominant throughout most of the evaluation, possibly due to the higher sugar content in white chocolates. The results indicate that the incorporation of powders rich in natural pigments can modulate the sensorial profile of chocolates, offering consumers more complex and diversified taste experiences, without significantly compromising the overall acceptance of the product.

In a study carried out by Roman et al. (2022), the sensory profile of mayonnaise enriched with sea buckthorn carotenoid microcapsules was evaluated by an untrained panel. Using a hedonic scale and 20 untrained tasters, attributes such as color, aroma, taste, consistency, texture, smell, aftertaste, spreadability, and acceptability were evaluated. The Mayo 2 sample, with 5% encapsulated extract, presented the highest scores in all evaluated attributes. However, differences between samples were not statistically significant for most attributes, such as texture, aroma, aftertaste and spreadability. The tasters noticed a clear difference in color, with Mayo 2 being more yellowish. The enriched mayonnaise was evaluated as having a balanced aroma and color, as well as a pleasant consistency.

The studies covered in this section demonstrated that the sensorial quality of dairy products, bakery products, confectionery products and oils with the addition of different microencapsulated pigments are influenced by several factors, including the type of pigment, level of inclusion and the type of product to be incorporated. The importance of employing the appropriate sensory test when carrying out sensory analysis is highlighted. The choice of sensory test is an important factor, highlighting that trained evaluators should not perform hedonic tests due to their objective approach and limited number of participants. Other studies used a very small number of consumers in their sensory analyses, although it is recommended to use between 80 and 100 consumers as a basic sample size. These limitations raise doubts about the significance of conclusions based on these sensory results, and future research on natural pigments in food products should approach sensory analysis with greater rigor (Souza et al., 2025a, b).

Notably, certain attributes such as color and flavor stand out as determining attributes in consumer preference. The strong visual influence of color on the perception of freshness, naturalness and healthiness explains this preference, especially in products enriched with green (chlorophyll) or red/purple pigments (anthocyanins). Similarly, the improvement in flavor and the absence of unpleasant notes, such as astringency or bitterness, increased acceptance, especially when the concentrations of pigments balanced visual appeal and taste. These results indicate that consumers value both the functional benefits of natural pigments and the emotional and perceptual stimuli they provide. Therefore, future research should deepen the understanding of these sensory and psychological factors in order to optimize the development of new products.

Recent years have seen exponential growth in interest in natural pigments, driven by the growing demand for healthier and more natural foods. Figure 3, a network visualization map generated using the VOSviewer software, with keywords from journals indexed in different databases (Web of Science, Scopus, SpringerLink, Wiley Online Library), reveals extensive collaboration between different areas of knowledge in this field. Each circle on the map represents a term or keyword, with the size of the circle indicating the frequency of use of that term in the publications. In addition, the distances between words play an important role in interpretation: the smaller the distance between two keywords, the greater the number of co-occurrences between them (Lv et al., 2021).

Fig. 3.

Network visualization map of publications on natural pigments, namely, (A) grouping of co-occurrence keywords and (B) publication trends from 2021 to 2025

Over the five-year period, a variety of articles were identified, concentrated in four large groupings: microencapsulation, application, evaluation of pigment stability, optimization of extraction and molecular studies on synthesis and degradation. Studies show that microencapsulation is an effective tool for stabilizing and preserving the functional properties of these pigments, expanding their applications in food products. This technology significantly improve the solubility, thermal stability and lightfastness of pigments, allowing their incorporation into a wide range of foods without compromising sensory and functional quality. At the same time, genetic studies have deepened the understanding of the molecular mechanisms that regulate the biosynthesis and degradation of natural pigments in plants. Although it is an emerging field, it has been possible to verify great discoveries, opening new perspectives for the optimization of processes that improve the stability of these compounds. Although the advances are notable, there is still great potential to explore the interaction between pigments and external factors such as light, temperature and pH, with the aim of developing more effective strategies to minimize degradation and extend the shelf life of products.

In recent years, there has been growing scientific interest in understanding how the human body absorbs and uses natural compounds present in foods. As shown in Fig. 3B, that presents a temporal space, using a color scale to represent the average year of occurrence of the keywords (ranging from dark blue, indicating terms predominant in previous years, to yellow, representing more recent terms). It can be seen that terms such as “spray drying”, “microencapsulation”, “anthocyanins”, and “chlorophyll” are in blue-green colors, indicating that they were central topics in previous years, reflecting an initial focus on encapsulation techniques and model compounds. On the other hand, terms such as “bioavailability”, “biaccessibility”, “digestion”, “Natural dye”, ‘proteomics’ and “ultrasonication” appear in yellowish tones, suggesting a recent trend towards deeper research into the functionality of bioactive compounds, especially with regard to their stability in food matrices, behavior during digestion and strategies to improve their effectiveness in the body (between 2023 and 2024). This temporal transition reveals a thematic evolution in the area, with a progressive shift from a technological emphasis to a more integrative approach, considering biological and nutritional aspects.

The combination of genetic engineering and biotechnology techniques with the optimization of extraction and encapsulation processes has the potential to increase the production and stability of pigments, making them more accessible and economically viable for the industry. Despite numerous studies, there are still challenges to be overcome, such as optimizing extraction processes and understanding the interactions between pigments and components of the food matrix. Future research should focus on exploring new sources of natural pigments, developing more efficient delivery systems, and evaluating the effects of ingesting pigment-enriched foods on human health.

Although there are numerous studies on the applications of natural pigments in food matrices, few studies have addressed the sensory aspects and consumer perception regarding products enriched with natural pigments, which represents an important gap, given that consumer acceptance is essential for the commercial success. Future studies should prioritize sensory analysis of products formulated with natural pigments, including hedonic and descriptive tests that identify key attributes of accessible use. Furthermore, new applications can be explored in vegan products and functional drinks, aligning with health and sustainability trends in the food market.

Author contributions

Lorrane Ribeiro de Souza: Writing – review & editing, Writing – original. draft, Visualization, Software, Investigation. Estela Côrrea de Azevedo: Writing – review & editing, Writing – original draft, Visualization, Software, Investigation. Juliete Martins Dutra: Review and editing. Wallace Carlos de Sousa: Writing – review & editing, Writing – original draft, Visualization, Investigation. Elisângela Elena Nunes Carvalho: Writing – original draft, Software Clarissa Damiani: Conceptualization and Supervision. Eduardo Valério de Barros Vilas Boas: Conceptualization and Supervision.

Data availability

The datasets generated during and analyzed during the current study are available from the corresponding author upon reasonable request.

Code availability

Not applicable.

Declarations

Conflict of interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. This work is original and has not been submitted or considered for publication in any other journal.

Ethical approval

All authors of this manuscript have read and approved its final version and are fully aware of its submission to the Food Science and Biotechnology.

Consent for publication

All authors have given their consent for publication.