Optimization of the Bioactivation of Isoflavones in Soymilk by Lactic Acid Bacteria

Soybeans and soy-based products contain isoflavones which can be used for nutraceutical medical applications. In soybeans in unfermented soy foods, are normally present as glycosides. Isoflavone glycosides enzymatically converted to isoflavone aglycones, thus releasing the sugar molecule. The effective absorption of humans requires bioconversion aglycones through activity enzyme β-glucosidase. objective was assess capacity 42 bacterial strains (belonging Lactobacillus, Streptococcus Enterococcus) produce β-glucosidase activity. strain that showed highest (Lactobacillus plantarum 128/2) then optimization genistin daidzin commercial soymilk their aglycone forms genistein daidzein. contribution process parameters (temperature, inoculum size, time) efficiency such bioactivation tested. Lactobacillus 128/2 able completely bioactivate under following conditions: 25 °C temperature, 2% size 48 h time. These results confirm suitability lactic acid bacteria provide an interesting candidate (L. 182/2) food industries perform this transformation.