BIOTECHNOLOGY OF SOYA MULTI-COMPONENT FUNCTIONAL INGREDIENTS

The materials of the article present analytical and scientific-practical results of research of soy multi-component functional ingredients. Soy extract (or soy milk) is a valuable and cheap source of protein and other nutritious and biologically active components, like lipids, vitamins, mineral elements, isoflavones, flavonoids, saponins etc. But the presence of indigestible oligosaccharides and a bean flavor limit the consumption of soy milk. The soy oligosaccharides are known to be prebiotic for intestinal microbiota, particularly for probiotic microorganisms that hydrolyze them with the enzyme α-galactosidase. Isoflavones are known as phytoestrogens since they are similar to human estrogen in structure and function, and are recommended to prevent many hormonedependent diseases. In soy beans and unfermented soy products, isoflavones are present mainly as biologically inactive glycoside conjugates. Biologically active aglycones of soy isoflavones are substances that are assimilated by human organism from soy products faster and in higher amounts than their corresponding glycosides. The members of intestinal microbiota are predicted to play an important role also in the metabolism and bioavailability of isoflavones since they, synthesizing β-glycosidase, cause hydrolysis of glycoside components, thus releasing the bioavailable and biologically active form of aglycone. In this work, we estimated the potential of some Lactobacillus and Bifidobacterium strains to synthesize α-galactosidase and β-glycosidase, and to reduce respectively the amount of galactooligosaccharides and to convert isoflavones into their active forms, when growing in soy milk. Simultaneously, the profile of soy milk fermentation by the chosen probiotics was studied, as well as the proteolytic activity and accumulation of lactic acid by those probiotics, i. e. the possibility to produce soy-based polyfunctional fermented food products was investigated.