Enhancement of isoflavone aglycone, amino acid, and CLA contents in fermented soybean yogurts using different strains: Screening of antioxidant and digestive enzyme inhibition properties

• Published in: Food chemistry 2021-03, Vol.340, p.128199-128199, Article 128199
• Main Authors: Hwang, Chung Eun, Kim, Su Cheol, Kim, Du Hyun, Lee, Hee Yul, Suh, Hyun Kwon, Cho, Kye Man, Lee, Jin Hwan
• Format: Article
• Language: English
• Subjects: Amino acid; Amino Acids - analysis; Antioxidant activity; Antioxidants - analysis; Antioxidants - pharmacology; Digestion; Enzyme inhibition; Enzyme Inhibitors - analysis; Enzyme Inhibitors - pharmacology; Fermentation; Glycine max - microbiology; Isoflavone; Isoflavones - analysis; Isoflavones - pharmacology; L. brevis; L. plantarum; Linoleic Acids, Conjugated - analysis; Soybean; Species Specificity; Yogurt - analysis; Yogurt - microbiology
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.128199

•Soy-powder yogurts (SPYs) were fermented by L. brevis and L. plantarum strains.•Total isoflavones in SPYs were significantly reduced with the increase of aglycones.•Amino acids increased remarkably with the predominant composition, ornithine.•SPYs exhibited higher CLA and GABA contents than soy-powder milks (SPMs).•Antioxidant and digestive inhibition effects markedly increased after fermentation. This study was the first to evaluate changes in isoflavone, amino acid, conjugated linoleic acid (CLA), antioxidant effect, and digestive enzyme inhibition during fermentation of soy-milk to soy-yogurt with L. brevis and L. plantarum. Total average isoflavones were reduced (1318.2 → 971.1 μg/g) with an increase of aglycones (60.2 → 804.9 μg/g, genistein > daidzein > glycitein) in soy powder yogurts (SPYs). Amino acids increased considerably, as did ornithine (average 4.1 → 551.0 mg/g), and CLA showed high variations from not-detected (ND) to 0.5, 0.9 mg/g (cis-9, trans-11) and ND to 0.3, 0.2 mg/g (trans-10, cis-12). Digestive enzyme inhibitions (α-glucosidase, α-amylase, and pancreatic lipase) displayed high activities (average 50.6 → 67.2, 5.2 → 46.4, 10.6 → 51.4%). Moreover, the antioxidant abilities against radicals were elevated as follows: ABTS > DPPH > hydroxyl (average 63.5 → 86.5, 50.2 → 70.3, 39.3 → 55.2%). Specifically, SPY using mixed strains exhibited the greatest enzymatic inhibition and antioxidant capacities.