Effect of spent brewer's yeast β-D-glucan on properties of wheat flour dough and bread during chilled storage

Production of yeast cell wall polysaccharides-β-glucan and chitin by using food waste substrates: Biosynthesis, production, extraction, and purification methods

Food waste causes significant environmental and economic challenges worldwide, prompting many nations to prioritize its reduction and recycling. As a nutrient-rich material containing vitamins, proteins, and carbohydrates, it serves as a promising substrate for the cultivation of single-cell microorganisms like yeast. Yeast cell wall polysaccharides (YCWPs), particularly chitin and β-glucans, offer valuable applications in food, pharmaceuticals, and bioprocessing. This review highlights the biosynthesis, production, extraction, and purification of YCWP cultivated on food waste substrates. Key species including Saccharomyces cerevisiae, Pichia pastoris, and Candida spp. are discussed, with a focus on optimizing chitin and β-glucan yield through mechanical, chemical, and enzymatic extraction methods. In addition, the structural and functional properties of β-glucans and chitin in maintaining cell wall stability are explored, emphasizing their potential as prebiotics, dietary fibers, and biodegradable packaging materials. This review also examines the valorization of food waste in yeast cultivation, presenting a sustainable bioprocessing strategy for transforming waste into valuable bioproducts.

Beta-Glucans in Biotechnology: A Holistic Review with a Special Focus on Yeast

Beta-glucans (β-glucans) are polysaccharides with significant biological activity, widely recognized for their immunomodulatory, anti-inflammatory, and metabolic health benefits. Among various sources, yeast-derived β-(1 → 3), (1 → 6)-glucans have gained particular attention due to their potent bioactivity and diverse applications in biotechnology, pharmaceuticals, and functional foods. This review comprehensively examines yeast β-glucans, covering their biosynthesis, extraction, and purification from industrially relevant yeast strains, particularly Saccharomyces cerevisiae. The impact of fermentation parameters on β-glucan yield and structural properties is analyzed, highlighting advancements in optimizing microbial production. Furthermore, we discuss methods for characterizing yeast β-glucans, including analytical and bioassay techniques, and compare their physicochemical properties with those of β-glucans from other sources. Finally, this review explores the therapeutic potential of yeast-derived β-glucans, focusing on their role in immunomodulation and metabolic regulation and their emerging applications in biomedicine, functional foods, and industrial formulations. By synthesizing recent advancements, this work provides insights into the expanding utilization of yeast β-glucans and their potential for future biotechnological developments.

Advances in the valorization of brewing by-products

Beer is the most consumed alcoholic beverage worldwide, and its production involves the generation of a huge volume of by-products (i.e., spent grain, spent hop, and spent yeast). This review aims to highlight the main properties of these by-products as a valuable source of biomolecules (i.e., proteins, cellulose, hemicellulose, lignin, phenolic compounds, and lipids) and the biorefining methods used in the last decade for their valorization. The pros and cons of the technologies employed will be shown, highlighting which of them could be more ready for the transition to an industrial scale, and which applications (e.g., food and feed, bioenergy, biochemicals, and biomaterials) are the most feasible.

Yeast polysaccharides: The environmentally friendly polysaccharides with broad application potentials

Yeast cell wall (YCW) polysaccharides, including β-glucans, mannans, chitins, and glycogens, can be extracted from the waste of beer industry. They are environmentally friendly, abundant, inexpensive raw materials, and have shown broad biological activities and application potentials. The exploitation of yeast polysaccharides is of great importance for environmental protection and resource utilization. This paper reviews the structural features and preparation of YCW polysaccharides. The solubility and emulsification of yeast polysaccharides and the properties of binding metal ions are presented. In addition, biological activities such as blood glucose and lipid lowering, immune regulation, antioxidant, promotion of intestinal health, and promotion of wound healing are proposed, highlighting the beneficial effects of yeast polysaccharides on human health. Through modification, the physical and chemical properties of yeast polysaccharides are changed, which emphasizes the promotion of their biological activities and properties. In addition, the food applications of yeast polysaccharides, including the food packaging film, emulsifier, thickening agent, and fat alternatives, are focused and discussed.

Enhancing Gluten Network Formation and Bread-Making Performance of Wheat Flour Using Wheat Bran Aqueous Extract

Wheat bran possesses diverse nutritional and functional properties. In this study, wheat bran aqueous extract (WBE) was produced and thoroughly characterized as a functional ingredient and improver for bakery application. The WBE contained 50.3% total carbohydrate, 24.5% protein, 13.0% ash, 6.7% soluble fiber, 2.9% insoluble fiber, and 0.5% β-glucan. Notably, adding 7.5% WBE significantly increased the bread-specific volume to 4.84 cm3/g, compared with the control of 4.18 cm3/g. Adding WBE also resulted in a remarkable improvement in dough properties. The WBE-enriched dough showed increased peak, setback, breakdown, and final viscosities, along with higher storage and loss modulus. Scanning electron microscopy analysis further revealed that the WBE promoted the aggregation of protein and starch within the dough. The extractable gliadin to glutenin ratio increased with 5 and 7.5% WBE additions, compared with the control and 2.5% WBE addition. WBE did not significantly alter the starch gelatinization temperature or dough extension properties. These findings demonstrate that the inclusion of WBE in wheat flour is a promising approach for producing high-quality bread that is enriched with dietary fiber and protein.

Effect of different molecular weight β-glucan hydrated with highland barley protein on the quality and in vitro starch digestibility of whole wheat bread

Whole wheat bread has high nutritional value, but it has inferior baking quality and high glycemic index, which needs to be improved by methods such as adding protein and β-glucan. This study investigated the effects of β-glucan and highland barley protein of different molecular weights (2 × 104, 1 × 105, and 3 × 105 Da) and different hydrate methods (pre-hydrate and not pre-hydrate) on the characteristics of whole wheat dough and bread. The mixing properties and rheological properties demonstrated that β-glucan pre-hydrated with highland barley protein were able to reduce the dough tan δ, reduce the dough viscoelasticity, while enhance the gluten network structure and dough deformation resistance. Compared to the control sample, the medium molecular weight pre-hydrate bread had a better specific volume of 3.21 mL/g, lower hardness of 527.28 g. In vitro starch digestion characteristics and ATR-FTIR showed that low and high molecular weight pre-hydrate increased the short-range ordered structure of starch and reduced the starch digestibility, while not pre-hydrated medium molecular weight hydrate had the lowest level of starch digestibility.

Structural characteristics of β-glucans from various sources and their influences on the short- and long-term starch retrogradation in wheat flour

Beta-glucans possess the ability of retarding starch retrogradation. However, β-glucans from different sources might show various influences on retrogradation process and the structure-function relationships of β-glucans related to the feature still remains unclear. In the study, the β-glucans from oat (OG), highland barley (HBG), and yeast (YG) were selected. Each β-glucans formed aggregate as observed by atomic force microscopy. OG and HBG with a lower Mw aggregated more obviously and exhibited higher intrinsic and apparent viscosity. The two β-glucans showed more restraining effect on the short-term starch retrogradation in the sol-like test system (RVA) and the long-term starch retrogradation in the gel-like test system (DSC). However, YG with a higher Mw exerted a greater retarding effect on the short-term starch retrogradation in gel-like test systems (Mixolab and rheology). LF-NMR indicated that OG and HBG increased the population of less-bound water by wrapping around the starch. In summary, the structural characteristics of β-glucan (Mw and aggregation state) and experiment condition (solid content) jointly influenced starch retrogradation, because a lower Mw and higher aggregation capacity β-glucan interacted more readily with starch and inhibited more starch re-association due to the higher diffusion rate in the sol-like system.

Antibacterial, antioxidant and fruit packaging ability of biochar-based silver nanoparticles-polyvinyl alcohol-chitosan composite film

Silver nanoparticles were prepared by loading Ag+ into biochar of waste barley distillers' grains shell by reduction with trisodium citrate, and this silver-loaded biochar was introduced into polyvinyl alcohol-chitosan. Various analysis with Fourier Transform Infrared spectroscopy, X-ray diffraction, Thermogravimetric analysis, and water contact angle revealed that biochar-based silver nanoparticle was incorporated into the polyvinyl alcohol-chitosan film, the biochar-based silver nanoparticles-polyvinyl alcohol-chitosan (C-Ag-loaded PVA/CS) composite film had good thermostability and hydrophobicity. Through the analysis via disk diffusion method, the composite containing 3 % of biochar-based silver nanoparticles-polyvinyl alcohol-chitosan had high antibacterial activity (inhibition zone: 18 mm against E. coli and 15 mm against S. aureus), and the bacterial membrane permeability was measured, indicating that C-Ag-loaded PVA/CS composite film could destroy the cell membrane, release intracellular substances, and have high antioxidant activity. During the storage, the weight loss rate of the biochar-based silver nanoparticles-polyvinyl alcohol-chitosan plastic wrap group was 0.14 %, and the titratable acid content only decreased by 0.061 %, which had a good effect on extending the shelf life of blueberries. The C-Ag-loaded PVA/CS composite film could also delay deterioration of blueberries and prolong storage time. Overall, this composite film had potential in food packaging and extending food shelf-life aspects.

Preparation of hydroxypropyl starch/polyvinyl alcohol composite nanofibers films and improvement of hydrophobic properties

Starch-derived edible films have great potential as biodegradable food packaging and biomedical materials, in this study, we adopted a green method to prepare starch-based composite electrospun nanofibers films. The hydroxypropyl starches (HPS) were prepared to improve native starch solubility and properties, and a series of blend solutions were prepared with different HPS/polyvinyl alcohol (PVA) weight ratios. The comparison of the properties of HPS/PVA (HPA) nanofibers with different amylose contents were evaluated, and the fibers fabricated from hydroxypropyl high amylose starch (HP-HAS) had more continuous and homogeneous morphologies compared to the other starch fibers, it was also found that the addition of HP-HAS in the film has better mechanical properties than pure PVA film. Thus, to improve the hydrophobicity of the film, the HP-HAS/PVA (HPA(H)) nanofiber was selected for the hydrophobic study by the citric acid (CA) treatment. The hydrophobic surface was formed on the HPA(H) film by CA self-assembled coating with a water contact angle changed from 30.95° up to 100.74°. This study successfully prepared the modified starch/PVA composite nanofibers and established a simple method of self-assembled hydrophobic modification to improve water stability. Therefore, this green strategy is an alternative candidate in further study for food packaging and relative areas.

Effect of mulberry leaf polysaccharides on the baking and staling properties of frozen dough bread

BACKGROUND

Deterioration in frozen dough bread easily occurs in store, resulting in tremendous economic waste. Therefore, it is imperative to find natural additives to improve storage staling. The effects of mulberry leaf polysaccharides (MLP) were studied in terms of baking, retrogradation and microstructural aspects in frozen dough bread.

RESULTS

The incorporation of MLP improved the specific volume and reduced the hardness of bread during room storage, with 1% MLP showing the best results. The results of X-ray diffraction and Fourier transform infrared spectroscopy showed that crystallinity was decreased and the formation of double helical structure was inhibited with the incorporation of MLP. Meanwhile, the results of low-field nuclear magnetic resonance demonstrated that the addition of MLP was advantageous for retarding water migration and distribution, with reduced water loss. It can be seen intuitively from scanning electron microscopy that MLP improved the gluten network with a smoother and flatter system.

CONCLUSION

MLP improved the quality of bread during storage and delayed the degradation of internal structure, and can be used as an effective natural additive to improve the storage stability of baked food. 1% MLP showed the best results. © 2022 Society of Chemical Industry.

Improvement of the gel properties and flavor adsorption capacity of fish myosin upon yeast β-glucan incorporation

The potential effects of yeast β-glucan (YG) on heat-induced gel properties, microstructure and flavor adsorption capacity of fish myosin at different NaCl concentrations were investigated in this study. The incorporation of YG significantly improved the texture properties, gel strength, water holding capacity (WHC), storage modulus and loss modulus of myosin gels, especially at a high salt level, whereas the whiteness declined. Furthermore, myosin gels containing YG displayed a more compact and ordered three-dimensional network structure, accompanied by the increasing immobilization of water in gels. The binding abilities of gels to selected flavor compounds at high salt content were inferior to those at the low salt content. Regardless of the salt level, YG addition boosted the flavor binding capacity of gels, which might be attributed to the unfolding of the protein conformation by exposing more flavor-binding sites, as well as the porous sponge structure of YG with unique adsorption capacity.

Biotechnological Addition of β-Glucans from Cereals, Mushrooms and Yeasts in Foods and Animal Feed

Varied cereal plants including, mushrooms, yeast, bacteria and algae are important sources of β-glucans, and many extraction procedures have been used in order to recover these valuable naturally occurring polysaccharides. The rheological and molecular properties of β-glucans can be utilized to be incorporated into various foods and to offer properties extremely beneficial to human health. Their functional effects are mainly determined by their molecular and structural characteristics. Consumption of foods fortified and enriched with β-glucans can contribute to the treatment of certain chronic diseases. Reduced cholesterol, cardiovascular and diabetic risk and moderate glycemic response of foods have been recorded with the consumption of these biologically active compounds. In addition, β-glucans are characterized by anti-cancer, antioxidant, anti-inflammatory and antiviral activities. As β-glucans interact with the foods in which they are incorporated, this review aims to discuss recent applications with quality and nutritional results of β-glucans incorporation with foods such as beverages, dairy, bakery, meat and pasta products, as well as their addition in animal feeds and their uses in other fields such as medicine.

Spent Brewer's Yeast as a Source of Insoluble β-Glucans

In the brewing process, the consumption of resources and the amount of waste generated are high and due to a lot of organic compounds in waste-water, the capacity of natural regeneration of the environment is exceeded. Residual yeast, the second by-product of brewing is considered to have an important chemical composition. An approach with nutritional potential refers to the extraction of bioactive compounds from the yeast cell wall, such as β-glucans. Concerning the potential food applications with better textural characteristics, spent brewer’s yeast glucan has high emulsion stability and water-holding capacity fitting best as a fat replacer in different food matrices. Few studies demonstrate the importance and nutritional role of β-glucans from brewer’s yeast, and even less for spent brewer’s yeast, due to additional steps in the extraction process. This review focuses on describing the process of obtaining insoluble β-glucans (particulate) from spent brewer’s yeast and provides an insight into how a by-product from brewing can be converted to potential food applications.