Changes in active compounds and biological activities during fermentation of soy-powder milk by the mixtures of probiotics lactic acid bacteria

Abstract

This study evaluated changes in γ-aminobutyric acid (GABA), isoflavones, and antioxidant activities during fermentation of soy-powder milk (SPM) by Lactobacillus brevis WCP02 and Lactobacillus plantarum P1201 starters. The levels of glutamic acid (GA) were significantly increased during first 24 h of SPM (100.38 → 290.13 mg/100 g) then decreased after 72 h of SPM to 177.91 mg/100 g. The GABA contents obviously increased from 32.05 mg/100 g to 76.22 mg/100 g between 0 and 72 h of SPM. Levels of isoflavone-glycosides, including daidzin, glycitin, and genistin, significantly decreased (746.23 → 24.04 μg/g, 183.52 → 76.00 μg/g, and 980.72 → 10.08 μg/g, respectively), as levels of isoflavone aglycones, such as daidzein, glycitein, and genistein, significantly increased (52.03 → 577.01 μg/g, 12.95 → 66.48 μg/g, and 38.62 → 462.42 μg/g, respectively) during fermentation of SPM. The antioxidant activity and inhibitory effect on digestive enzyme (1 mg/mL) also considerably increased during fermentation of SPM: DPPH (30.23 → 88.50%), ABTS (59.71 → 74.54%), and hydroxyl (65.51 → 76.10%) radical scavenging activities and pancreatic lipase (8.00 → 34.53%) and α-glucosidase inhibition (12.38 → 45.38%) activities. Copyright ? The Korean Society of Food Preservation. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.