Fortification of camel milk bio-yogurt with brewer’s spent yeast cell wall by-products: Effects on physiochemical properties, nutritive value, and sensory characteristics

The polysaccharides of the spent brewer's yeast cell wall of Saccharomyces cerevisiae are insoluble material in water and alkali solutions, which assumes its biological actions and limits its appliance range. In the present study, we applied a new ultrasound-assisted H2O2/ascorbic acid degradation method (IYP-UO) to improve the solubility of brewer’s spent yeast polysaccharides cell wall (β-glucan) and compared that with the traditional acid degraded method (IYP-A). This study aimed at determining the possibility of addition solubilized (IYP-UO β-glucan) at different ratios (0, 0.2, 0.4, and 0.8%) and effects on the improving physiochemical properties, and sensual characteristics of camel milk bio-yogurts during storage at 5°C. Compared with the IYP-A degradation method, the IYP-UO method was the most effective method to increase the total (1→3) (1,6)-β-D-glucan (%) and decrease the crude protein of the extracted samples. Fortified camel bio-yogurts with 0.4 to 0.8% of IYP-UO β-glucan accelerate the fermentation time, improved organoleptic parameters and increased viscosity, DPPH and FRAP activity compared to both the IYP and control bio-yogurt samples. This study provides an efficient ultrasound-assisted H2O2/ascorbic acid method as a new degradation green method for producing high solubilized and high purity yeast β-glucan from polysaccharides yeast cell wall β-glucan by-products. In addition, fortified camel bio-yogurts with solubilized β-glucan revealed an improvement in the physiochemical and sensory characteristics of camel milk bio-yogurts. Further studies on the functional properties are needed concerning the technological and physiological of milk products containing solubilized β-glucan.