Fermented Milk Beverages Fortified with Soy Protein

Introduction. Fermented milk beverages with various vegetable additives expand the range of functional foods with probiotics, vitamins, and minerals. The research objective was to develop a new technology for fermented milk drinks fortified with soy protein. Study objects and methods. Heat-treated cow’s milk with Direct Vat Set bacterial starter served as the control sample, while the experimental samples featured fermented milk fortified with soy additives. The soy protein ingredient was obtained from powdered sprouted soybean. Soybeans were pre-germinated in a thermostat at 26°C for 24 h and blanched with steam for 15 min. After that, 1–9% of the soy substance was added to pasteurized milk and fermented at 38–40°C for 6–8 h. The resulting sample was tested for quality indicators and physicochemical composition. Results and discussion. The best sensory properties belonged to the sample with 5% mass fraction of the soy additive. As a result, the soy-fortified beverages entitled Bifivit and Immunovit had a better nutritional value: protein – by 1.92 and 1.79 g, fat – by 0.77 and 0.75 g, vitamin E – by 0.16 mg, choline – by 23.82 mg, potassium – by 149 mg, phosphorus – by 19 and 22 mg, calcium – by 25 and 24 mg, magnesium – by 22 and 23 mg, respectively. One portion (100 g) of these drinks contained over 15% of recommended daily intake of protein, vitamin B2, potassium, magnesium, calcium, and phosphorus. The content of lactic acid and bifidobacteria remained above the norm (1×108) both in fresh products and by the end of their shelf life. Conclusion. The article introduces a technology of new functional soy-fortified fermented milk drinks with improved chemical and sensory properties.

Investigation of Enzymatic Hydrolysis Kinetics of Soy Protein Isolate: Laboratory And Semi-Industrial Scale

Soy protein isolate is a worthy substitute for meat protein. However, its low level of digestibility limits its spread to new market niches. This problem can be solved by enzymatic hydrolysis of soy protein to peptides. Several research teams have already been solving this problem, but their results were obtained under laboratory conditions and do not provide information about the reproducibility of the results on an industrial scale. In this paper, we have compared the results of laboratory and semi-industrial experiments of enzymatic hydrolysis of protein. Also the kinetics of the reaction under different conditions is shown, and the final product is characterized. The obtained results of semi-industrial experiments can form the basis of industrial regulations for the production of soy protein hydrolysate as an easily digestible form of dietary protein for athletes and patients with digestive disorders.

Carbon Black Replacement in Natural Rubber Composites Using Dry-Milled Calcium Carbonate, Soy Protein, and Biochar

Recent discoveries have shown that calcium carbonate and soy protein interactions can be used to reinforce rubber composites with improvements on the effective crosslink density and moduli. However, the method to incorporate the soy protein into the rubber matrix may be costly to scale up, since it involves microfluidization and drying steps prior to rubber compounding. In this work, a simpler process involving dry-milled calcium carbonate and soy protein was used to explore filler blends of calcium carbonate, soy protein, biochar, and carbon black. By blending these filler materials in various ratios, rubber composite samples with 40–50% of the carbon black replaced by sustainable alternatives were made. These composites had essentially the same tensile strength, with better toughness and elongation properties relative to the carbon black control. These composites would reduce dependence on petroleum and be more amenable to the rubber composite compounding infrastructure.