Production and application of xanthan gum—prospects in the dairy and plant-based milk food industry: a review

Abstract

Xanthan gum (XG) is an important industrial microbial exopolysaccharide. It has found applications in various industries, such as pharmaceuticals, cosmetics, paints and coatings, and wastewater treatment, but especially in the food industry. The thickening and stabilizing properties of XG make it a valuable ingredient in many food products. This review presents a comprehensive overview of the various potential applications of this versatile ingredient in the food industry. Especially in the plant-based food industries due to current interest of consumers in cheaper protein sources and health purposes. However, challenges and opportunities also exist, and this review aims to identify and explore these issues in greater detail. Overall, this article represents a valuable contribution to the scientific understanding of XG and its potential applications in the food industry.

Introduction

In the food, medical, and other industries, polysaccharides of algae, plants and microorganisms are of great importance. Exopolysaccharides (EPS), which are high molecular weight carbohydrate polymers synthesized in cells and secreted by microorganisms, have been discovered since 1950 (Borges et al., 2008). These EPS differ in their biocompatibility, biodegradability, adsorption, and other physicochemical properties based on their source (Mahmoud et al., 2021). The Preparation of microorganism-based polysaccharides using bioreactors takes significantly less time than polysaccharides from algae and plants that dominate the market. In addition, EPS can be produced from industrial raw materials or waste materials as carbon sources (Donot et al., 2012; Kojić et al., 2016). Recent advances in technology and genetic engineering have led to improvements in the physicochemical properties and production of EPS, thereby widening its scope of application (Bhat et al., 2022; Steffens et al., 2022).

A few microbial polysaccharides, such as dextran, microbial cellulose, gellan gum, and xanthan gum, have been industrially produced commercially. XG has been widely used in the food industries because of its rheological properties in aqueous solutions (Freitas et al., 2011). It is a microbial exopolysaccharide produced by Xanthomonas spp. during aerobic fermentation (Palaniraj and Jayaraman, 2011). The gum shows tremendous thickening ability and provides the body for the materials attachment and therefore maintaining their consistency in food products (Freitas et al., 2011).

XG has received considerable attention recently owing to its possible use in the production of dairy and plant-based milk products. Milk and dairy products with low fat content, as well as products based on vegetable milk, have low colloidal stability. Sedimentation, separation, or syneresis can occur during storage. This separates the product into phases that are undesirable for the product quality. The use of stabilizers of a polysaccharide nature is necessary to improve the quality of such food products and their acceptability to consumers. It also allows for an increase in shelf life. The gum is an effective emulsifier and stabilizer that prevents the separation of ingredients, as well as a thickener, and has broad prospects in the production of food products based on milk and vegetable milk.

Current reviews on XG focus on detailed applications in the pharmaceutical and cosmeceutical industries (Nordin et al., 2020), delivery of therapeutic agents (Jadav et al, 2023; Tuteja and Nagpal, 2023), and oil recovery (Bhat et al., 2022). In addition, the biosynthesis and industrial production of xanthan were highlighted by Rashidi et al. (2023) in their review.

This review provides an overview of the major advances in XG production, including recent results on the genetic modification of X. campestris to improve the exopolysaccharide production as well as the use of cheaper carbon sources and general parameters for its production. It also includes general uses, with a focus on recent applications in dairy and plant-based dairy products.

Overview of xanthan gum

Xanthan is very effective as a thickener and stabilizer in a wide range of food products and has a number of advantages over other food hydrocolloids such as starch, modified starch, galactomannans such as guar gum and locust bean gum, carboxymethyl cellulose, etc., which are widely used as thickeners in the food industry. It can be used both hot and cold. It is also effective in preventing ingredient separation and can help prolong the shelf life of products (Urlacher et al., 1997). In addition, the gum is stable over a wide range of pH levels (2 to 12 pH), temperatures (− 18 °C to 120 °C), and is not affected by enzymes, making it suitable for use in various food products (Bak and Yoo, 2018; Dziezak, 1991; Saha and Bhattacharya, 2010).

Compared to guar gum, XG is more soluble in foods containing sugar or salt. Locust bean gum is also insoluble in cold water, unlike xanthan. Guar gum and locust bean gum are known to degrade and lose viscosity at high and low pH values and at high temperatures (Saha and Bhattacharya, 2010). One of the main disadvantages of xanthan is its high cost compared to other thickeners and stabilizers. Also, its production requires the use of genetically modified bacteria, which may be a concern for some consumers.

The safety of xanthan has been intensively investigated. Research conducted on the acute toxicity of orally administered xanthan in an animal model showed that there was no observed toxicity up to 20 g/kg body weight (Freitas et al., 2014). Up to 1% XG has been administered to rabbits to assess its effect on dermal irritation and sensitivity, but the results showed no irritation effects (Fiume et al., 2012).

A study was conducted to examine the toxicological effects of xanthan on humans. Over a period of 23 days, daily ingestion of 10.4–12.9 g of the gum did not result in any significant changes in plasma biochemistry, hematological indices, urinalysis parameters, glucose and insulin tests, serum immunoglobulins, triglycerides, phospholipids, HDL cholesterol, or breath hydrogen or methane concentrations. However, the study did reveal a 10% decrease in serum cholesterol levels and a notable increase in fecal bile acid concentrations following XG consumption. Additionally, the study confirmed that the gum acted as a bulking agent, affecting fecal dry and wet weight and transit time as expected from a dose-ranging study (Eastwood et al., 1987).

In infants less than 16 weeks, toxicological results showed that, the highest exposure of 312 mg/kg per day of xanthan used in food for special medical purposes does not raise a concern (EFSA Panel on Food Additives and Flavourings (FAF) et al., 2023).

Digestibility and calorimetric availability tests have been conducted and results indicate that XG is non-digestible in humans but improves the passage of food (Fan et al., 2008). According to Fan et al. (2008) xanthan may not be metabolized by the body and therefore does not contribute to daily calorie or macronutrient intake. The reason is that people do not produce xanthan hydrolyzing enzymes. However, currently it has been discovered that a significant number of people in industrialized countries have gut microbiota capable of digesting XG. This digestion process breaks down XG into monosaccharides, which are then fermented to produce short-chain fatty acids that can be utilized by the human body. Therefore, it is possible that XG could contribute to a person's overall calorie intake. The intestinal bacteria of the Ruminococcaceae family in human microbiomes, especially in developed countries, have acquired the ability to hydrolyze the main chain of xanthan. Some people have Bacteroides, intestinal bacteria that can consume oligosaccharides produced by Ruminococcaceae (Ostrowski et al., 2022).

XG has an estimated worldwide production of 30,000 tons per year and an increasing production rate of 5–10% per year (Jesus et al., 2023). Over the past years, the market value of the gum has steadily increased. In 2012 and 2013, its value was USD 173.3 and 176.3 Mn respectively. Recently, during the forecast period of 2023 to 2032, xanthan market is projected to experience a compound annual growth rate (CAGR) of 3.2%, resulting in a market worth approximately USD 1250 Mn by 2032. There is a significant increase in its value USD 901 Mn in 2022 compared to the previous value USD 650 Mn in 2021. The anticipated growth can be attributed to the rising demand for sustainably and ethically sourced products, which is expected to drive market expansion. However, the market share by application, 2022, food and beverages, oil and gas, pharmaceutical and cosmetic industries are the main shareholders (Xanthan Gum Market, 2023). China and Australia have become the main exporters of XG. There is a need to enhance the production of xanthan to meet the current demands. The main cost in the production of XG is the raw material; therefore, it is prudent to use industrial waste and agricultural waste as substrates to reduce the cost of production (Gunasekar et al., 2014).

XG production is sustainable and does not cause significant damage to the environment. It has a low carbon footprint (7.8 kgCO₂e/kg) compared to other foods and ongoing research is being done to optimize the production process (https://apps.carboncloud.com). Agro-industrial organic by-products are being explored as a sustainable alternative source of nutrients, and wastewater from food industries is being considered as a source of water for the fermentation process (Dey and Chatterji, 2023). However, transferring these approaches to an industrial scale is limited due to considerations of security of supply and raw material quality.

Chemical structure of xanthan gum

The molecule of xanthan is composed of linearly linked by β-1,4-glycosidic bonds β-d-glucoses that form the backbone. Every second glucose residue contained a side chain of three monosaccharide units (mannose, glucuronic acid, and another mannose residue). Approximately 50% of the terminal mannose residues contain pyruvate linked to mannose by a 4,6-ketal bond, and non-terminal mannose residues contain an acetate group, as shown in Fig. 1 (Kool et al., 2014). The conformation of this exopolysaccharide is significantly influenced by the acetyl and pyruvyl groups on its side chains. Specifically, acetyl groups stabilize the ordered conformation, whereas pyruvyl groups disrupt it (Yuan et al., 2022). The molecular weight and chemical composition depend primarily on the Xanthomonas strain, medium composition, and cultivation conditions.

Fig. 1.

Chemical structure of xanthan gum

The native XG structure is disordered when subjected to heat between the temperatures of 25 °C to 120 °C at a 1% concentration in water. On cooling, the helical structure is gained but not completely (Jeanes et al., 1961).

The polymer is stabilized by salt; hence the importance of salt concentrations in the efficiency of the gum (Pastor et al., 1994). The gum possesses a strong recrystallization stability because of its air binding force. (Nordin et al., 2020).

Xanthan gum producing bacteria (Xanthomonas spp.)

Xanthomonas spp., is a Gram negative phytopathogenic bacterium that infects cruciferous crops as well as brassicas. The bacteria are also noted for the production of exo-heterogeneous polysaccharides known as XG, which is of great industrial importance (Becker, 2015; Mansfield et al., 2012; Steffens et al., 2022). Modern biotechnology has helped establish a groundbreaking method by identifying the genes responsible for the synthesis of xanthan. Through genetic engineering, the gene responsible for the synthesis of xanthan, 12 genes within a cluster named gum, controlled by multiple promoters, have been identified (Alkhateeb et al., 2016). For instance, Steffens et al. (2022) has created a-two flagella mutants of X. campestris, which have proven to enhance xanthan production and higher xanthan viscosity. In addition, X. campestris CGMCC15155 has been genetically engineered to reduce the cost of downstream processing for xanthan gum production. These engineered bacteria have the ability to reduce the ethanol required during the downstream processing by 133.3%, with an improvement in the whiteness of the gum color (Dai et al., 2019). Moritz and colleagues (2019) have also produced seven xanthan variants by genetic modification of X. campestris LMG 8031. These variants possess good acetylation and pyruvylation patterns in the natural state, which improve their rheological functions in salt-free environments and in the presence of mono- and divalent cations. Using marker-less gene knockout and gene overexpressing procedures in X. campestris CGMCC15155, a variant xanthan was produced. The variants demonstrate that the terminal mannose containing the pyruvate group and internal mannose containing the acetyl group determine the secondary structure and the rheological properties of the gum. While the internal acetyl group provides stability for the helix structure of xanthan, the pyruvyl group provides the opposite (Wu et al., 2019). Other species of Xanthomonas including X. arboricola, X. axonopodis, X. vaculorium, X. citri, X. malvacearum, X. carotae, X. gummisudans, X. jugladis, X. fragaria, and X. phaseoli can be used in the production of XG industrially (Petri, 2015). However, the bacterial strain and carbon source have a significant effect on the quality and quantity of the gum produced (Rončević et al., 2019a) as shown in Table 1. The most commonly used bacterial species industrially is X. campestris.

Table 1.

Influence of bacteria strain and carbon source on xanthan yield

Bacteria strain	Carbon sources	Xanthan yield, g/L	References
X. citri subsp. Citri/NIGEB-386	Cheese whey	22.7	Moravej et al. (2020)
X. axonopodis pv. mangiferaeindicae	Glycerin	3.1	Gondim et al. (2019)
X. axonopodis vesicatoria	Hydrolyzed bread solution	14.3	Demirci et al. (2019)
X. campestris ATCC 13951	Winery wastewater	23.9	Rončević et al. (2019b)
X. campestris PTCC 1473	Pre-treated Elm wood	10.4	Jazini et al. (2018)
X. campestris MO-03	Sugar beet molasses (with chicken feather peptone supplements)	20.5	Ozdal and Kurbanoglu (2019)
X. campestris pv. campestris 1866 and 1867	Cocoa husk	4.5	da Silva et al. (2018)
X. campestris PTCC 1473	Broomcorn stem	8.9	Soleymanpour et al. (2018)
X. campestris PTCC 1473	Orange peel hydrolysate	30.2	Mohsin et al. (2018)

Production of xanthan gum

The desired properties of XG are maintained through preservation of a selected microbial strain, which is then expanded for large-scale production using a bioreactor. Growth and production are influenced by various factors including the type of bioreactor, mode of operation, culture medium composition, and dissolve oxygen concentration (Borges et al., 2008; Nasr et al., 2007; Papagianni et al., 2001; Rosalam et al., 2008). After fermentation, the bacterial cells are then separated from the broth. The gum is precipitated out of the broth and the product is dried, milled, and packaged into an airtight material to prevent water permeability (García-Ochoa et al., 2000b). Figure 2 depicts the production scheme of XG.

Fig. 2.

Flow chart depicting the production of xanthan gum

Factors affecting the production and properties of xanthan gum

Carbon sources

Cell growth and reproduction require the manufacture of various components through nutrient ingestion. Different cells use different carbon and energy sources due to varying internal chemical processes. XG structure is not affected by growth phases or medium alterations, but rather by changes inside chain structure, yield, and molecular mass(Davidson, 1978). The most used carbon sources are glucose and sucrose. Diverse bacterial cultures require different growth media and optimal conditions for production. As such, the nutrient requirements for the purpose of variations within the side chain and optimum conditions for the biosynthesis of xanthan have been established (Letisse et al., 2001). The carbon source concentration affects the yield of the gum; hence, a concentration between 2–4% is preferable (Palaniraj and Jayaraman, 2011; Funahashi et al., 1987). Growth inhibition may occur at high concentrations of carbon in medium.

When X. campestris was used in an experiment by Leela and Sharma (2000) using variant carbon sources, glucose, sucrose, maltose, arabinose, soluble starch, and potato starch has a high yield of XG between 9.754 and 14.744 g/L. Moderate yields were obtained from fructose, xylose, and galactose, between 5.232 and 7.129 g/L of xanthan. However, much lower yields were obtained from lactose, inositol, and sorbitol, between 1.008 and 1.502 g/L of the gum. Other carbon sources have been explored for xanthan production including cheese whey (25 g/L) (Silva et al., 2009), green coconut shell (5.5 g/L), passion fruit peel (6.7 g/L), corn cob (2.7 g/L), (Santos et al., 2016), and corn straw (8.37 g/L) (Jesus, et al., 2023), which are regarded as cheaper carbon sources using different Xanthomonas spp.

A report by Zhang and Chen, (2010) revealed that the preferred carbon source to produce XG was glucose in an experiment using xylose/glucose mixture media, where a little portion of the xylose was utilized. Table 1 provides other cheaper carbon sources used in the production of the gum.

Nitrogen sources

Nitrogen is an essential nutrient and is provided in the form of organic or inorganic molecules. Organic nitrogen sources, which include peptone, yeast extract, corn steep liquor and soybean meal are more expensive than the inorganic sources which include ammonium or nitrate salts (Nordin et al., 2020; Souw and Demain, 1979; Vuyst et al., 1987). Among these sources, yeast extract and peptone are the most appropriate for xanthan production (Bhatia et al., 2015; Chavan and Baig, 2016), while ammonium salts, an inorganic source, are appropriate for biomass accumulation (Letisse et al., 2001). Nevertheless, nitrate is preferred for maximum XG yield. The optimum carbon to nitrogen, C/N ratio during fermentation stage, 20 has been established by Soleymanpour et al. (2018). It has also been reported that higher nitrogen sources which are essential for cell growth and enzyme production were not relevant during the production of the gum (Khosravi-Darani et al., 2011; Moshaf et al., 2014). Controlling the level of nitrogen during the fermentation process is important for both economic efficiency and product quality. A higher level of nitrogen is needed for rapid cell growth in the initial phase, but it must be reduced later on to allow for a purer product and to save on raw material costs. This helps to promote the growth of bacteria and synthesis of XG (Kuppuswami, 2014).

Temperature

Temperature is also a principal factor in XG production. The variation of temperature mainly during the growth phase of the inoculum affects the production of the gum. For a maximum yield in production, the optimum temperature has been found to be between 28 and 30°C (Borges et al., 2008; García-Ochoa et al., 2000b; Gumus et al., 2010; Kerdsup et al., 2011; Murad et al., 2019; Psomas et al., 2007; Silva et al., 2009). According to research, the temperature range for the cultivation of X. campestris is between 25–27°C which is slightly different from the temperature range to produce XG, 25–30°C (Infee Sherley and Priyadharshini, 2015; Murad et al., 2019). The viscosity of the gum is affected due to temperature variations. Temperatures between 25 and 35°C have shown an increase in gum production, however, the reverse may occur with further increase in temperature and cause a reduction in biomass production (Chavan and Baig, 2016; Infee Sherley and Priyadharshini, 2015). Above 34°C temperature during xanthan production may affect the molecular conformation, thus low acetate and pyruvate contents, low molecular weight on average leading to a less viscous aqueous solution (Casas et al., 2000). Below 25°C temperature produces gum with high acetate and a high molecular weight leading to high viscous aqueous solution (Lopes et al., 2015). It was reported that, best temperature to produce xanthan is dependent on the production medium (Shu and Yang, 1990).

pH

The pH during the production of XG is especially important as it affects the charge density of the gum. This changes the molecular interaction between the xanthan molecules and hence affects the viscosity of the gum (Murad et al., 2019; Rinaudo and Moroni, 2009). For X. campestris, the optimum pH during growth phase is between 6.0 to 7.5 while during the production of the gum is also between 7.0 to 8.0 (Esgalhado et al., 1995). According to García-Ochoa et al. (1996) a neutral pH is also good for the cultivation of X. campestris. Alkali including KOH, NaOH, or (NH)₄OH are preferred for an efficient production of xanthan when used to control the pH within the range of 6.0 and 8.0 (García-Ochoa et al., 2000a). For bacterial growth, a pH between 6.0 and 7.0 and temperature between 25–27°C is a favorable condition, while for gum production with better viscosity, a pH around 8.0 and 30°C temperature were reported to be preferable. The growth of bacteria was observed to have been affected by controlled pH with a significant effect on the production of xanthan (García-Ochoa et al., 2000a; Infee Sherley and Priyadharshini, 2015; Palaniraj and Jayaraman, 2011). Between a pH range of 6.0 to 8.0, it has been observed that the viscosity of xanthan was not affected. The acetyl group of the polymer is lost at a basic pH of 9.0 or more (Tako and Nakamura, 1984), while the pyruvic acid groups are lost at pH less than 3.0 (Bradshaw et al., 1983). According to research, alkali stress during gum production increases gum yield (de Mello Luvielmo et al., 2016). The decrease in the pH during the fermentation process to around 5.0 because of the acid group in the structure of XG may lead to a decrease in productivity (Borges et al., 2008; García-Ochoa et al., 2000b).

Agitation and aeration rate

Agitation and aeration rates are important during the production of XG due to the aerobic nature of Xanthomonas spp. Oxygen mass transfer decreases during the production process because of the extracellular deposition of xanthan (García-Ochoa et al., 2000a). Again, increasing viscosity during the production process disturbs the aeration in the media as well as the distribution and uniformity of nutrients (Palaniraj and Jayaraman, 2011). Studies have shown that the rate of oxygen dissolution is directly proportional to the production of gum (García-Ochoa et al., 2000a). It is very important to have oxygen level on high in the media for effeciency of the bacteria due to its aerobic nature (Donot et al., 2012). Therefore, it is necessary to always check the air flow rate and the agitation speed since they affect the production of xanthan (Borges et al., 2008). Nevertheless, too high aeration rate may cause hydrodynamic stress leading to cell damage and hence reduction in gum production. The prevent this problem, the mixing condition needs to be optimized (Freitas et al., 2011). Thus, due to the probability of cell damage using high speed of agitation, the speed should be kept optimal for an efficient production (Infee Sherley and Priyadharshini, 2015). Conversely, low agigattion speed may also affect the rate of oxygen dissolution leading to low production of gum. However, high agitation rate have a better effect on gum production than the time of fermentation, as it has been confirmed that 1000 rpm at 50 h of fermentation time has the highest productivity (Amanullah et al., 1998). In a laboratory experiment, gas–liquid mass transfer resistance has been overcomed using hydrogen peroxide as an oxygen source in the fermentation medium (Cheng et al, 2012).

Operation mode and fermentation time

In XG production, either batch or continues fermentation operation can be employed even though the former is highly efficient (75–80%) in converting substrate to gum but uses about 48 h during the entire process (Rosalam and England, 2006). During this period of fermentation, the viscosity of the medium increases and this disturbs the oxygen level in the medium leading to reduced gum production because of limiting nutrient accessibility (Infee Sherley and Priyadharshini, 2015). Again, unfavorable conditions for gum production may arise due to changes in the external environmental conditions during a longer period of fermentation (Rosalam and England, 2006).

By the optimization of fermentation conditions such as bioreactor, substrate type, and the strain used, higher yield of XG can be achieved (Nordin et al., 2020). Nevertheless, the fermentation period is related directly to the cell growth dynamics and substrate availability (Gilani et al., 2011; Letisse et al., 2001). The growth rate of the cell declines as the substrate is consumed completely and hence the process comes to a halt, therefore continuous fermentation is preferred in order maximize the time and the biosynthesis of xanthan. During the continuous fermentation process, there is an intermittent feed of culture medium that helps to achieve optimum and continuous nutrient availability (Infee Sherley and Priyadharshini, 2015; Rosalam and England, 2006), and has a substrate conversion efficiency to be between 60–70% (Becker, 2015). Research has revealed that continuous culture methods are greatly used in industries. This mode has the demerit of considerable risk of contamination and difficulty in maintenance of constant setup (Infee Sherley and Priyadharshini, 2015).

Enhancers of production

Various compounds are used to stimulate the quality and quantity of xanthan during its production. If an organic nitrogen source is being used, increasing in the nitrogen concentration enhances the formation pyruvate (Palaniraj and Jayaraman, 2011). In a study conducted by Cadmus et al. (1978), (NH₄)₂HPO₄ used as a nitrogen source proved to be the most preferred as it helps increase pyruvate content. Molina et al. (1993) has also reported that there has been an increase in yield and viscosity of XG with the addition of 1 g/l of corn steep liquor, as well as promoted the utilization of carbon source and hence reducing the cultivation time. Xanthomonas species are stimulated by organic acids present in growth medium. Citric acid added as a chelating agent during heat sterilization, prevents salt precipitation leading to an improved productivity of XG. Xanthan solubility in solutions is improved by the addition of acetic acid which is a weak carboxylic acid and easily dissolves the gum (Shehni et al., 2011). The conformational characteristics and stability of the polymer can be maintained by the addition of NaCl to the production medium before thermal treatment (Lutfi et al., 2019; Reinoso et al., 2019).

Recovery and purification of xanthan gum

XG is recovered and purified through an energy-intensive and costly process, alcoholic precipitation, which involves deactivating and removing bacteria cells, precipitating the biopolymer, and drying and milling it. This can be done through chemical treatment, mechanical means, or thermal treatment, but chemical treatment (alkali, or hypochlorite) may cause de-pyruvylation of the gum and enzymes used during fermentation must be removed. Pasteurization or sterilization of the fermentation broth is also necessary to kill bacteria cells. (Smith and Pace, 1982; Garcia-Ochoa et al., 1993). At a suitable condition of thermal treatment (80–130 ^o C, 10–20 min, 6.3–6.9 pH) of broth, the gum is dissolved without degrading and the bacteria cells gets disrupted (Smith and Pace, 1982). It has been reported that the viscosity of the fermentation is reduced with increase in temperature, this will allow for easy centrifugation or filtration of the insoluble. If the fermentation broth is highly viscous, usually, it is thermally treated or diluted with either water, alcohol, or a mixture of CaCl₂ and alcohol in a lower quantity not to precipitate the polymer (Garcia-Ochoa et al., 1993; Smith and Pace, 1982). The quantity of the reagent is dependent of the nature, thus the alcohols it contains. Resaerch reveals that for a total precipitation to occur, isopropanol, acetone, or alcohol can be used in 3 volumes to the broth (Rottava et al., 2009; Salah et al., 2010; Zhang and Chen, 2010). Lower alcohols such as ethanol required that less than or equal to 4 volumes of alcohol is used per broth volume (Borges et al., 2008). Xanthan can also be precipitated with 2 volumes of isopropanol as report by Gumus et al. (2010).

Applications of xanthan gum

Recently, naturally originated materials have gained a broad acceptability across all the spheres of human lives due to their abundance, effectiveness of costs, environmentally benign, and sustainability (Yue et al., 2018; Hasnain et al., 2019). Aside from this, XG has impacted the global market because of its simple production mechanisms and reproducibility. Owing its special rheological property, cold and warm water solubility, high and stable viscosity at low concentrations, it has received enormous consideration for various purposes. The helical conformation of XG made it possible to be used as pseudo-plastic and in suspension as well as in the recovery of industrial wastes (Habibi and Khosravi-Darani, 2017; Petri, 2015). It is used in the pharmaceutical industries, biomedical engineering, agriculture, and other related fields of science as shown in Table 2.

Table 2.

Applications of xanthan gum

Application	Quantity of xanthan (%, w/w)	Role	References
Agriculture	‒	Improve the rheology, stability, and the flow properties in fungicides, pesticides, and herbicides	Palaniraj and Jayaraman (2011)
Biomedical engineering	‒	Excellent water solubility, gelation, and biocompatibility are therefore used in drug delivery, protein delivery system, and tissue engineering	Petri (2015)
Pharmaceuticals	≥ 1.0	Stabilizer, binder, thickener, emulsifier, gelling or matrixing agent	Fu et al. (2019) and Bouyer et al. (2013)
Oil industry	~ 25.0	Water-based fluid viscosity control and maintenance, elevated temperatures and salinity less sensitivity, polymer flooding	Huang et al. (2020) and Jang et al. (2015)
Paper industry	–0.2	Rheology control and enhancement, suspension, and paper strength	Palaniraj and Jayaraman (2011)
Battery	~ 1.0	Used as a water-soluble binder for electrode materials to prepare safe and eco-friendly Li-ion batteries. For electrochemical performance enhancement	L´eonard and Job (2019)
Cosmetic industry	≥ 1.0	Rheological and flow characteristic enhancement of toothpaste, shampoo, liquid soap, and other cosmetic products	Saharudin et al. (2016) and Parente et al. (2015)
Wastewater treatment	–	Use with other nanofillers for effective adsorption, gelation, ecofriendly, swelling, thermal stability, and good mechanical strength	Ahmad and Mirza (2018), Ahmad and Mirza (2017), and Thakur et al. (2017)
Paints and coatings	0.1–0.4	Used as thickening, stabilizer, improve texture and surface affinity, and corrosion prevention	Palaniraj and Jayaraman (2011) and Babaladimath et al. (2018)

Food applications of xanthan gum

XG is a regulated food additive with maximum allowable levels established by food safety agencies such as the FDA and EFSA. The specific guidelines for its use in edible films and food packaging vary by country and agency. The EU has set a maximum level of 2000 mg/kg, while the FDA has set a maximum level of 0.5% by weight (Council of the European Union and European Parliament, 2008; Food and Drug Administration, 2023). It is important to label and declare xanthan as an ingredient to help those with allergies or sensitivities.

Xanthan, when used in foods, improves the fluidity, mouthfeel, and the adhesion of the product and therefore very suitable for thickening, stabilizing, and suspension in beverages. It can therefore be used in gravies and sauces, dairy foods, bakery, relish, syrup and toppings, beverages, food dressing edible films and packaging, as shown graphically in Fig. 3. The gum is also used as a gluten replacement in gluten-free products because it can partially replace gluten while maintaining product properties and is sold as a separate dietary supplement for keto/low carbohydrate diets.

Fig. 3.

Graphical representation of food application of xanthan gum

Dairy

In the dairy industry, xanthan gum is used as stabilizer with the blend of other gums such guar gum, locust bean gum (LBG), or both in the production of ice creams, sorbet, and milk chocolates. It is very productive in frozen dairy products such as yoghurts. When mixed with guar gum and locust bean gum, it improves the strength and flavor release in cheese spread. Economically mixing of the gum provides effectiveness in processing heat transfer, optimal viscosity, long-term stability, release of flavor, ice crystal control protection, and heat shock (Rosalam and England, 2006). Blends of guar, LBG, and xanthan improve the flavor release, slice ability, and the firmness of cream cheese. The syneresis is reduced in ice creams and thus improve consistency when xanthan is used (Suryawanshi et al., 2022). With galacto-mannans like guar gum, LBG, and the glucomannan konjac mannan, xanthan interacts synergistically. With guar gum, this increases viscosity, and with LBG and konjac mannan, it produces soft, stretchy thermally reversible gels. For a variety of frozen and chilled dairy products such ice cream, sherbet, sour cream, sterile whipped cream, and recombined milk, blends of XG, carrageenan, and galactomannans are good stabilizers. These affordable mixes may be purchased already prepared to offer the best viscosity, long-term stability, enhanced heat transmission during processing, and protection from heat shock (Ghebremedhin et al., 2021).

Beverages

XG is used in beverages prepared with fruit and serves as a support for pulps, maintenance of the suspensions. As such, it provides the materials in the beverages and squashes with body. Xanthan improves the mouthfeel and dissolves quickly even at low pH completely. For insoluble solutions, it provides them with a credible suspension and that makes it suitable for almost all beverages (Suryawanshi et al., 2022). Coconut protein is a byproduct of the manufacturing of commercial coconut oil, but its low dispersibility prevents it from being used in food. In order to further define the physicochemical characteristics of coconut protein and increase its solubility and dispersion at food-grade quantities of pH, NaCl, and xanthan, research was done. It was then revealed that by increasing the viscosity and the negative charge of the surface particles, 0.4% XG was added to a coconut protein solution to induce fluid-like behavior without precipitation. So, a 2% protein coconut protein-xanthan solution might be employed in the food business, such in protein beverages (Kaewmungkun and Limpisophon, 2023).

Bakery

During the periods of baking and storage, XG is used to elevate the water binding activity of baked products and refrigerated doughs in the bakery industry. It maintains a good gluten and starch network in dough during frozen storage conditions and hence improves the final bread quality (Ahmed et al., 2021). Xanthan can be blended with egg white powders as it helps to increase the surface tension, particle size, viscosity and interfacial adsorption well as decreasing surface hydrophobicity during the preparation of cake batter (Li et al., 2023). In gluten free and baked products, it improves the texture and volume. In an experiment by Chakraborty and colleagues on the selection and incorporation of hydrocolloids for gluten-free leavened millet bread, XG proves to be most suitable, rendering an acceptable bread structure (Chakraborty et al., 2020). Analysis of the frozen and cooked cheese bread dough's moisture content, pH, specific volume, and density was done in an experiment to develop cheese bread with the addition of guar and XG as a partial replacement for fat. Better qualities than guar gum or a combination of the two gums were obtained with the addition of xanthan. The formulations including XG had better texture, larger volume, and lower density, which are desirable qualities in baked bread. They also had higher moisture retention and better texture in the frozen dough. The treatments that included the gum and a 55% decrease in partial fat (soybean oil) improved the moisture, density, and specific volume of the baked bread and open the door to the development of low-calorie bread by largely replacing the fat content of conventional commercial formulations (Papalia et al., 2015).

Food packaging and edible films

As a result of the special pseudoplastic and physicochemical properties that contribute to the formation of films, XG can be employed as a material for food packaging (Raschip et al., 2020; Rukmanikrishnan et al., 2020). Again, its high stability in either cold or warm water, viscosity consistency at varying pH and temperature (thermal tolerance), makes it more appropriate in the manufacturing of packaging films. This polysaccharide has been used as a crosslinking agent to create nanofibers that reduce water vapor permeability, water solubility, and moisture content abilities (Maroufi et al., 2023). Practically, xanthan used as coatings for banana has improved on the shelf life and decreased the release of flavor during storage (Zheng et al., 2022). The non-toxic nature exhibited by the polymer makes it suitable for use as edible film production. There is also the possibility of improving the quality and the consumer acceptability of extruded snacks by replacing the fat used for coating and flavoring with this polymer (Graça et al., 2020). Xanthan and gellan gum-based nanocomposites have been created using zinc oxide as a nanoparticle. The zinc oxide nanoparticles were necessary to improve the transparency and the antimicrobial properties of the product. The nanocomposites exhibited higher ultra-violet light shielding, thermal stability, and water barrier property. This makes the product very useful as a food and pharmaceutical packaging material (Tao et al., 2016; Rukmanikrishnan et al., 2020). Composite films made of polyvinyl alcohol (PVA) and XG were prepared using the casting method. The addition of XG to PVA resulted in a decrease in moisture content, water solubility, and water vapor transmission compared to pure PVA films. The composite films exhibited superior food packaging capabilities compared to commercial plastic bags and completely decomposed in soil and water within 12 h, making them a potential alternative packing material that is renewable, sustainable, and environmentally friendly (Chen et al., 2022).

Food dressing

Almost every food after preparation is given “final touch” to improve its appearance. As such salad dressings, XG is employed to provide and improve a clean mouthfeel. It is also a perfect substitute for inconsistent starch and lower calorie salad dressings. In this case, offers stability during freeze–thaw, improves appearance, and provides body stability. Aside from the above, xanthan also improves upon the organoleptic properties when used in food dressing (Suryawanshi et al., 2022).

Sauces and gravies

In both acidic and neutral sauces and gravies, XG provides high viscosity even at low levels. In temperature fluctuations the viscosity in this case is extremely stable even at long term storage periods. These sauces and gravies with xanthan hold on to warm foods and are associated with great release of flavor and textural appearance (Suryawanshi et al., 2022). The rheological and sensory properties of dessert sauces thickened by starch-xanthan mixes has been assessed by Sikora et al. (2007). It has been revealed that less amount of xanthan (0.12%) blended with potato sauce, is needed to increase the thickening capacity of sauce to the desired effect.

Syrups and toppings

The enormous characteristics of XG in solutions is very keen and employed in syrups and toppings. Xanthan in buttered syrups and chocolate toppings provides a very great consistency and improves the flow ability due to its high viscosity. Products like ice cream, cooked meats, and pancakes appear thick and salivating when XG is used (Rosalam and England, 2006). A very great freeze–thaw stability, firm texture, and high overrun is associated with frozen no-dairy whipped topping concentrates (Suryawanshi et al., 2022).

Relish

XG improves on the overwhelming weight and efficiently takes off the loss of liquor during the handling stage in relish. Its usage in portion packed relish, aids in the maintenance of the seasoning, allow for even distribution of relish and liquor during filling and spattering is also prevented (Suryawanshi et al., 2022).

Dairy products and xanthan gum prospects

Milk and dairy products are the most important components of the human diet because of their high nutritional content. They provide the body with energy and high-quality protein as well as a wide range of essential micronutrients including magnesium, calcium, zinc, phosphorus, potassium and calcium. Milk and dairy products are also rich in vitamins such as the vitamins B, with a substantial amount of vitamin B₂ and the fat-soluble vitamins such as A, D, and E. (FAO, 2013). The major sources of dairy milk are cows, goats, sheep, buffalo, horses, and camels. They can be processed into other products such as yoghurts, cheeses, ice creams, and many others which possess different physicochemical properties.

Yoghurt is a fermented milk product, which has a microstructure composed of a 3D protein network consisting of casein micelles, water dipoles, fat globules and bacterial cells (Hassan et al., 2002). The casein network is relatively weak (Tidona et al., 2016) and hence the need for stabilizers to improve on the physicochemical properties. Different stabilizers can be used to improve the physicochemical properties of yoghurt (Anderson et al., 2002) including XG. For instance, xanthan can be used to improve the texture and stability of yoghurt by adding up to 1% of initial milk (Mehanna et al., 2020).

Also, XG can be modified to improve its properties when used in yogurt production. For instance, enzyme-hydrolyzed xanthan polysaccharide has also been proven to prevent syneresis and improve the viscosity, water-holding capacity, and texture of yoghurt when added up to 0.5%. Yoghurt quality was improved without adversely affecting organoleptic properties in an experiment to evaluate the effect of enzyme-hydrolyzed xanthan on yoghurt quality (Rafiq et al., 2020). In addition, the prebiotic potential of enzyme-hydrolyzed xanthan was investigated, and the results proved that it could be the best candidate for yoghurt production (Khalid et al., 2022).

Again, the addition of XG up to 0.01% improved and maintained curd tension during the yoghurt storage periods. In addition, the susceptibility of yoghurt to syneresis during storage decreased as a result of the addition of the gum, with no syneresis recorded at the beginning of the storage period (El-Sayed et al., 2002). During ten days of storage, samples with 0.01% XG exhibited the maximum viscosity in an experiment to determine the impact of gums on yoghurt properties. The syneresis of yoghurt samples was evaluated at 4°C and 25°C. According to these findings, samples containing gums showed reduced syneresis during storage. Samples with 0.01% xanthan showed strong resistance to syneresis during the storage period. The pH and total solid content of the samples containing xanthan did not change during the storage period. At the end of the storage period, the samples did not include any coliform groups, yeasts, or molds. In comparison to the other treatments, yoghurt treated with 0.005% XG had the highest sensory rating (Hematyar et al., 2012).

The stability of yoghurt products on the shelf is important for consumer acceptability, especially when fortified with other food ingredients. In general, hydrocolloids have the ability to stabilize these products and hence improve consumer acceptability. XG has been used synergistically with guar gum to stabilize β-carotene-loaded liposome dispersions in yoghurt. The mixture did not affect the liposome bilayer, but rather improved the stability of the product over time, even at low concentrations (Toniazzo et al., 2014). The use of xanthan and maltodextrin as encapsulant agents was also successful and applied in yoghurt production, even as it maintained the physicochemical properties, including pH, titratable acidity, humidity, and stability of the yoghurt during 40 days of storage (Antigo et al., 2020). When xanthan was used in addition to whey powder to stabilize foam in yoghurt smoothie, it was observed that the foam lasted for approximately 25 min with an appealing texture for customer attraction (Miano, 2022). Rosida et al. (2022) have also performed a work on the use of XG as a stabilizer for a symbiotic yoghurt ice cream made from ice cream mix and purple yam yoghurt (Dioscorea alata). The results revealed that 0.2% of the gum is needed to achieve the desired characteristics of the product, including viability of the probiotics.

Yoghurt, traditionally made from cow’s milk, can also be produced from other dairy milk sources, which may possess different physicochemical properties due to variations in nutritional composition. Park et al. (2019) assessed the impact of different gums on the textural and microbial viability of yoghurt made from goat milk. The results showed that, among other gums, XG enhanced the viscosity, firmness, consistency, and cohesiveness of the product during a four-week refrigerated storage. The gum also maintained the viability of the yoghurt culture and the probiotics used. Similar results were obtained by Ladjvardi et al. (2020) when camel milk was used to prepare yoghurt with xanthan.

The physicochemical properties and survival rate of probiotics in a bio-doogh (Iranian yoghurt drink) made up of wild thyme (Ziziphora clinopodioids) essence and XG were assessed. Bio-doogh is traditionally prepared from goat or sheep milk. These findings indicated that the addition of > 0.075% XG had no significant effect on the viability of the probiotics. However, 0.15% XG was required to improve the stability of the product (Ziaolhagh and Jalali, 2017).

Consumers are increasingly demanding low-fat products. There has been works to provide consumers with lower content products. For instance, research has shown that xanthan-modified fish gelatin could also be replacement for mammalian gelatin in low-fat stirred yoghurt with best rheological properties as reported by Yin et al. (2021).

Most dairy products contain up to 12% fat and are usually not preferred by consumers. Therefore, fat replacers were used in this case. Carbohydrate-based fat replacers are widely used because of their ability to form gels and trap substantial amounts of water in food systems (Akbari et al., 2019). Xanthan can be used as a fat replacement in fat-free dairy products. For instance, its use as a fat replacer in cheddar cheese has increased the cohesiveness and springiness of fresh cheddar cheese and has a positive effect on flavor release (Nateghi et al., 2012). Similar characteristics were obtained by Yang et al. (2012) for processed acid-coagulated cheese and cream cheese (Salari et al., 2017). Up to 0.07% XG can be used to produce low-fat white cheese with high consumer acceptability (Shendi et al., 2010). A low-fat mozzarella cheese supplemented with xanthan has improved fiber formation and string separation compared to other polysaccharides used, polydextrose, and starch (Oberg et al., 2010), which could increase product yield and solve problems associated with texture and functionality (Sattar et al., 2015). Alzamili and Al-Bedrani, (2022) also affirmed that when making low-fat, oshari-like cheese, xanthan was used to replace the fat, which increased the quality of the cheese.

XG can also improve other qualities of cheese made from cow milk including spreading ability and temperature stability. For example, it has been used to produce a softer and stickier cream cheese that has good spread ability with a wide range of temperature stability (Brighenti et al., 2019).

Cheese can also be produced from other dairy milks like buffalo milks. Murad et al. (2016) in an experiment to assess the impact of XG as a fat replacer using skimmed buffalo’s milk for low fat Kariesh cheese production discovered that, during 15 days of storage period, the gum has the potential to maintain the hardness and cohesiveness of this product. The inclusion of approximately 0.04% and 0.05% xanthan as a fat substitute improved consumer acceptability as well as the flavor of Kariesh cheese.

XG is not only used as an ingredient in cheese products but can also be used as an edible coating for the final product. Soleimani-Rambod et al. (2018) investigated the possibility of using xanthan and flaxseed mucilage as edible coatings for cheddar cheese. The results indicated that the free fatty acid composition of the product was affected by the edible coatings as well the pH, acidity, fat in dry matter, moisture, and protein content during 90 days of ripening. However, proteolysis, lipolysis, and sensory evaluation were not affected by the edible coatings or the growth of non-starter lactic acid bacteria and total mesophilic aerobic bacteria.

The role of hydrocolloids, including xanthan, in the improvement of the sensory properties of dairy beverages has been studied intensively by researchers. It has been revealed that xanthan as hydrocolloid could positively impact the creaminess, thickness, and fattiness sensation when used as an ingredient in dairy beverages (Ji et al., 2023). In addition, in some food products, such as keşkül, a dairy dessert, xanthan gum improves the hardness and gumminess of the product (Kadağan and Arslan, 2021). XG (0.325%) significantly influenced the stability and acceptability of acidified dairy cream. The gum masked the effect of the sensory perception of acidity due to the high viscosity provided (Sánchez-Ortega et al., 2017).

A study on the physical and chemical properties of gelatin-free desserts using 0.8% xanthan also revealed that the parameters obtained were comparable to those of a control sample containing gelatin. It was confirmed that creamy and pleasant consistency during chewing was improved by the addition of xanthan, which makes the product sensorially acceptable (Nepovinnykh et al., 2019). XG has also been used in a prebiotic dairy custard, a dessert of semi-solid consistency. Its effect on the product shows that the inclusion of xanthan up to 0.25% could prevent aggregation of inulin, a prebiotic in the custard, even as both inulin and xanthan polymer serve as a fat substitute, reducing the high fat content in this desert (Noreña et al., 2014).

Milk-derived protein ingredients are commonly used as food emulsifying agents, and hydrocolloids, such as XG, are added as stabilizers to develop low-fat emulsions. The rheological properties of oil-in-water emulsions (30% w/w) containing mixtures of milk proteins (sodium caseinate and whey concentrate) and xanthan were assessed. The results revealed that xanthan rheology outweighs emulsion rheology, even as the consistency of the emulsion was maintained during a month of storage, confirming the stability of the product (Vazquez-Solorio et al., 2011).

Xanthan has therefore been used in most dairy products, including yoghurt, cheese, dairy beverages, and desserts, as well as in other products from different milk sources, such as cows, buffaloes, goats, and camels. This has improved the quality of products, making them more appreciable by consumers, and hence a great future for the dairy industry.

However, there are growing concerns about the sustainability and ethical standards for the use of xanthan in the dairy industry. As consumers become more aware of environmental and ethical issues, a surge in demand for products derived from sustainable and ethical sources is expected. A global shift to a vegan diet is vital to saving the world from the worst effects of climate change, according to the United Nations. XG is produced without the use of animal products or by-products, making it suitable for vegan products such as plant-based dairy alternatives.

Plant-based milk products and xanthan gum prospects

The adoption of a dairy-free diet has been increasing in recent years, and plant-based milk products, commonly referred to as non-dairy milk alternatives, are gaining popularity. This is due to various reasons, such as milk allergy, lactose intolerance, hypercholesterolemia, and vegan diet (Mattison et al., 2020; Zheng et al., 2020). In addition, the vegan nutrition supply is also on the rise worldwide; hence, there is a need to explore plant-based milk and milk products (Santos et al., 2019; Yang et al., 2020).

Plant-based milk is produced from legumes, cereals, and oil seeds and is prepared in such a way as to resemble cow milk. Traditionally, plant-based milk is prepared by wet grinding the raw material and filtering the milk out of the coarse particles. The process is basically the same for all plant milk sources during processing, with subsequent removal of the residue, even on an industrial scale (Makinen et al., 2016).

Soy milk extracted from soybeans is one of the most consumed and preferred plant-based milks in the world, with a much better nutritional composition (Santos et al., 2019). It serves as a source of essential fatty acids and amino acids, and is free of cholesterol, gluten, and lactose. This means that it could be the best dietary source for vegetarians and lactose-intolerant populations (Toro-Funes et al., 2015). In addition, soymilk provides lecithin, isoflavone, vitamins, and other antioxidants that could help prevent anemia, cancer, and osteoporosis as well as alleviate menopausal syndrome (Fernandes et al., 2017).

Soy milk is typically an oil-in-water emulsion and presents a multicomponent system consisting of fats, proteins, and polysaccharides. These multicomponent may cause aggregation and separation of the phases. Therefore, relevant stabilizers are required to improve the stability (Dhankhar and Kundu, 2021). XG offers better compatibility with soy proteins with improved viscosity and hence stability in soy milk, even at a lower concentration of about 0.01% (Pang et al., 2020).

Fermented soymilk can improve the digestive gut environment and influence the gut microbiome. In this case, it could play a role in anti-aging by regulating the gut microbiome, as reported by Liu et al. (2020). Fermenting soymilk helps to reduce the undesirable beany flavor and enrich functional attributes (İçier et al., 2015; Li et al., 2014). One major physical setback of fermented soymilk is liquid-phase separation, which affects its texture and appearance. In the utilization of laboratory-produced xanthan in the manufacture of soy yoghurt, its inclusion of up to 0.005% has greatly influenced syneresis and the microstructure of the product. No syneresis was recorded in fresh samples with high sensory scores obtained from this product (El-Sayed et al., 2002). Among other hydrocolloids used in the preparation of soymilk yoghurt, xanthan has been proven to have a significant effect on the texture and rheological properties with increasing concentration in the product (Pang et al., 2019).

XG has also been used to manufacture other soymilk-related products. For instance, it (0.005 g per 100 g of milk) was used as a stabilizer in the development of blends of soy-maize milk yoghurt analogs and has improved enormously the product quality (Limbu et al., 2022). Low-fat ice cream was created using xanthan and soy protein hydrolysate in a ratio (8:92) to improve the stability of the product resistance to melting and sensory properties (Yan et al., 2021). In addition, soymilk containing 3% okara was used to create a probiotic creamy sauce using xanthan and guar gum. The results showed that the binary mixing of both xanthan and guar gum had the best possibility of having a high probiotic capacity and improved product quality (de Moraes Filho et al., 2018).

Other plant-based milk alternatives products are being developed recently from other plants, such as coconut, oat, wheat, rice, and almond, owing to lifestyle choices and medical reasons in recent times (Azi et al., 2020; Uruc et al., 2022). However, sedimentation, creaming, and syneresis can also occur during storage. This separates a product into phases that are undesirable for consumers. The ingredients, processing, and storage conditions during the production of plant-based milk products are crucial to the colloidal stability of the final product, which has a very short shelf life and limits its consumption (Makinen et al., 2016). Therefore, the use of hydrocolloids such as XG as a stabilizer is necessary to improve the final product and consumer acceptability.

The rapid evolution of plant-based milk and milk products is relatively new and challenging, particularly considering their physicochemical and sensory properties. Plant-based milk and milk products have relatively low viscosity and other challenging sensorial properties such as mouthfeel, off-color, and flavor (McClements et al., 2019). Sodium caseinate and xanthan have been used to improve the physical stability and consumer acceptability of tiger nut milk. Tiger nut milk systems enhanced with sodium caseinate and xanthan were superior to systems enhanced with guar gum in terms of increasing physical stability, particularly by producing systems with a higher temperature-stable viscosity. Tiger nut milk's sensory qualities and nutritional value both stand to benefit greatly from the inclusion of sodium caseinate and xanthan (Kizzie-Hayford et al., 2021).

Stabilizers are employed in the creation of plant-based yogurts to enhance their quality. In addition to enhancing texture, the use of pectin, XG, and maize starch contributed to the optimum viscosity and flow behavior of plant-based yoghurt. People who are lactose intolerant can use this product made from peanut, oat, and coconut milk as an alternative to cow milk because of its excellent sensory qualities, nutritional content, and physical and chemical features by the addition of xanthan (Nehaa et al., 2022).

The lack of a natural protein network in most plant-based milk and milk products, including millet and coconut, makes it difficult for it to be used in the production of traditional fermented milk products such as yoghurt. The xanthan polymer therefore provides this network within the product, thereby improving the product quality. For example, the addition of up to 0.15% XG to fermented millet and coconut milk improves its quality and organoleptic properties (Mauro et al., 2022; Song et al., 2020). Xanthan has also been used to stabilize plant-based fermented desserts. It resists mechanical stress, as reported by Madsen et al. (2021), when investigating the potential for developing a new plant-based fermented dessert, Chufa drink, produced using tiger nuts.

In the creation of vegan ice cream based on almond drink, it has been noted that a mixture of xanthan and locust bean gum used in the product had no significant effect on the physical parameters of the ice cream. However, they prevented recrystallization of the product and improved the organoleptic properties of the vegan ice cream (Kot et al., 2020). A recipe was also created for the brown rice milk-based vegan ice cream. The results indicated that the formulation with the highest approval in terms of physiological features and sensory assessment was the rice milk-based ice cream, which contained XG, guar gum, andcarrageenan. In this case, 0.15% inclusion of xanthan in this recipe improved the emulsification and consistency of the product (Mygdalia et al., 2023).

The use of XG in plant-based milk can also reduce the levels of aromatic compounds. Plant-based milk usually gives off flavors in the presence of aromatic compounds. According to research, α-pinene, β-myrcene, and D-lim-onene aromatic compounds have been lowered by the addition of xanthan to Pinus halepensis seed milk (Abbou et al., 2022).

Dairy analogs curd and kulfi have been developed by replacing cow milk with coconut and oat milk to meet the demands of consumers who do not want dairy products, where xanthan is used as a stabilizer (Kailaje et al., 2022). In addition, to provide a crème option for people who do not eat dairy-based products, plant-based milk was used, and xanthan was used as a stabilizer. This product can then be used in soups, sauces, smoothies, dressings, puddings, and frozen desserts (Kinkelaar and Palav, 2019).

In general, XG has a great future in plant-based milk and milk products due to its ability to improve on the physicochemical and sensorial properties. By incorporating xanthan into the formulation, plant-based milk and milk products achieve improved texture, stability, and sensory appeal, bringing them closer to the taste and experience of dairy milk. As such, intensive research should be done to provide the optimum application of the gum in different plant-based milk and products taking into account the production cost and quality of the product.

Prospects of xanthan in the dairy and non-dairy products

Currently, XG is widely used in the food industry and has good prospects. Owing to its multifunctionality, it does not only influences the rheological properties of food products but also varies the composition, creating new products, such as those that do not contain animal protein, low fat, lactose-free, gluten-free, etc.

The polysaccharide has recently received considerable attention due to its use in the production of dairy and plant-based milk products. Milk and dairy products with a low-fat content, as well as products based on vegetable milk, have low colloidal stability. Xanthan is an effective emulsifier and stabilizer that prevents the separation of ingredients, as well as a thickener, and has broad prospects for the production of food products based on milk and vegetable milk.

XG's compatibility with a wide range of ingredients commonly used in dairy and plant-based dairy products, including proteins, sugars, and flavors, is also an advantage for its use. Therefore, they are versatile and suitable for various compositions. With the growing popularity of plant-based milk alternatives and demand for dairy-free products, xanthan can play a critical role in improving the quality and organoleptic characteristics of these products, making them more appealing to consumers.

However, it is worth noting that some people may be sensitive or allergic to xanthan. Manufacturers should consider this aspect and provide alternatives for consumers with special dietary requirements or preferences. In addition, regulations and labeling requirements must be followed to ensure the proper use and declaration of the polymer in dairy and plant-based dairy products.

The market value of xanthan has risen over the years, and its production needs to be increased to meet demand. However, the main cost of production is the source of the raw materials. Therefore, it is necessary to use cheaper sources to reduce production costs. It is also necessary to intensify research on genetically modified xanthan-producing microorganisms to improve their performance and recovery in xanthan production. It is necessary to study its wide range of applications in the food industry, especially in dairy and plant-based dairy and milk products, in order to make more economically viable strategies for its use available, such as modifications, optimal inclusion levels in the food. As the demand for plant-based alternatives continues to grow, this polymer offers tremendous potential for the development of innovative and high-quality non-dairy products, expanding the choices available to consumers seeking a healthier, more sustainable lifestyle. It is also necessary to evaluate the influence of physiological and psychological responses, such as feelings of pleasure, hunger, and satiety, on the use of xanthan in plant-based milk and dairy products.

Declarations

Conflict of interest

Authors declare no conflict of interest.