Fortified Protein Concentrate Based on Milk Whey

Utilization and processing of milk whey have become a pressing problem for the dairy industry as a result of unprofitable production methods and the poor energy-saving industrial technologies. Milk whey is a valuable raw material that contains more than 200 organic and mineral components. It can be processes into products with useful biological properties. The article describes a new fortified protein curd whey product obtained with magnesium thermal coagulation of proteins and fermented with a complex lactobacillus starter. The curd whey was obtained by acid-rennet coagulation as a by-product of cottage cheese with a fat mass fraction of 9%. After +35–40°C in water bath, fat and casein powder were removed in a cream separator. The permeate was obtained by thermal denaturation at 92 ± 1°C with a 10% MgCl2×6H2O solution in concentrations of 2–42 g/L. The protein was then subjected to vacuum filtration. The fermentation of whey proteins involved a complex starter culture of four Lactobacillus strains. The research relied on standard physicochemical and microbiological methods. The optimal mode for thermal magnesium denaturation of milk whey was 92 ± 1°C for 5–10 min with 18 g/L MgCl2. It yielded 25.0 g/L protein with 2.4 mg/g magnesium. When the magnesium concentrate of thermally precipitated whey proteins was fermented with the complex starter culture, it activated the proteolysis process, as well as provided the targeted physicochemical and sensory properties. After freeze-drying at –40°C for 18–20 h, the powder obtained was rich in living lactobacilli cells (1–3×107) and contained 907 mg/100 g magnesium. The new method made it possible to turn whey wastes into a magnesium-containing concentrate of thermally precipitated proteins with increased biological value. Its qualitative indicators provide a wide range of possibilities in various areas of the food industry.