Recycling of yeast multifunctional autolysates and extracts in the food industry

Recycling of industrial waste is one of the most crucial problems for the food industry. The forces of modern researchers are focused on solving this problem and using the biopotential of spent resources. Residual yeast from fermentation industries, in particular brewing, is of particular interest among the variety of food production waste. This is due to the extremely rich chemical composition of the yeast cell, and the possibility of obtaining a wide range of ingredients that exhibit both biological activity and technologically significant properties. Spent brewer's yeast is rich in proteins and carbohydrates, as well as vitamins B and minerals. The protein fraction, which accounts for 45–60% by dry weight (dw), contains all essential amino acids in sufficient quantities, which allows considering this secondary material resource an excellent source of protein with high biological value and a well-balanced AA profile. The carbohydrate fraction, comprising approximately 40% by dw, consists of intracellular carbohydrates (such as simple sugars and glycogen) as well as cell wall polysaccharides (such as β-glucan and α-mannan). Special emphasis is placed on the cell wall components due to their significant multidirectional biological activity and technologically important properties. Thus, β-glucan and α-mannan, along with emulsifying, sorbing and stabilizing properties, exhibit antioxidant and antimicrobial activity, immunomodulatory and prebiotic properties. This review presents an analysis of yeast autolysates and extracts sources as well as the influence of cultivation conditions and production methods on their chemical composition

Residual brewing yeasts as a source of beta-glucans

Residual brewing yeast is one of the main solid wastes in brewing. Using residual brewing biomass as a source of biologically active substances is an important way of recycling these brewing by-products. According to the literature S. cerevisiae is considered as the promising source of polysaccharides, particularly beta-glucans. Beta-glucans are structural polysaccharides of the yeast cell and perform immune stimulating properties. At the same time, there is too little information about the content of these polysaccharides in brewing yeast of the genus Brettanomyces. The objects of this study were yeast cultures of Saccharomyces cerevisiae and Brettanomyces bruxellensis. In this work, the cultivations of the yeasts were carried out to compare them as possible sources of beta-glucans. The yeasts were cultivated in a simple periodic culture using a laboratory fermenter (Biostat A, Sartorius). As a result, the content of beta-glucans in the yeasts S. cerevisiae and B. bruxellensis biomass was measured by enzymatic method (Megazyme, Ireland). According to the obtained data, the yeast B. bruxellensis contains a higher amount of beta-glucans than the yeast S. cerevisiae

Proteomics Answers Which Yeast Genes Are Specific for Baking, Brewing, and Ethanol Production

Yeast strains are convenient models for studying domestication processes. The ability of yeast to ferment carbon sources from various substrates and to produce ethanol and carbon dioxide is the core of brewing, winemaking, and ethanol production technologies. The present study reveals the differences among yeast strains used in various industries. To understand this, we performed a proteomic study of industrial Saccharomyces cerevisiae strains followed by a comparative analysis of available yeast genetic data. Individual protein expression levels in domesticated strains from different industries indicated modulation resulting from response to technological environments. The innovative nature of this research was the discovery of genes overexpressed in yeast strains adapted to brewing, baking, and ethanol production, typical genes for specific domestication were found. We discovered a gene set typical for brewer’s yeast strains. Baker’s yeast had a specific gene adapted to osmotic stress. Toxic stress was typical for yeast used for ethanol production. The data obtained can be applied for targeted improvement of industrial strains

Valorization of residual yoghurt whey by lactic acid production: An optimized process

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