Department of Food Microbiology, Central Food Technological Research Institute, CSIR, Mysore, India.
Int J Food Sci Nutr. 2011 Mar;62(2):111-20. doi: 10.3109/09637486.2010.513680. Epub 2010 Nov 23.
Isoflavones significantly contribute to human health and disease prevention, and exist as glucosides and aglycones. The β-glucosidase enzyme that hydrolyzes glucosides to aglycones is very sensitive to molecular structure, and thus the profile of the isoflavones can affect their rate of hydrolysis. Soymilk was fermented with Lactobacillus acidophilus B4496 (La), Lactobacillus bulgaricus CFR2028 (Lb), Lactobacillus casei B1922 (Lc), Lactobacillus plantarum B4495 (Lp) and Lactobacillus fermentum B4655 (Lf) for 48 h at 37°C. β-Glucosidase activity was determined using p-nitrophenyl β-D-glucopyranoside as a substrate and the hydrolysis was carried out in soymilk. During fermentation, maximum growth was seen at 24 h with Lb, Lc, Lp and Lf and at 48 h with La. Polyphenol content ranged from 12.98 to 17.90 at 24 h and from 12.44 to 15.24 mg/100 ml at 48 h of fermentation. All the lactic acid bacteria produced β-glucosidase enzyme, which hydrolyzed isoflavone glucosides to aglycones at a significant level (P < 0.05) in the fermented soymilk.
异黄酮对人类健康和疾病预防有重要贡献，存在于糖苷和苷元形式。水解糖苷生成苷元的β-葡萄糖苷酶对分子结构非常敏感，因此异黄酮的形态会影响其水解速度。将豆浆与嗜酸乳杆菌 B4496（La）、保加利亚乳杆菌 CFR2028（Lb）、干酪乳杆菌 B1922（Lc）、植物乳杆菌 B4495（Lp）和发酵乳杆菌 B4655（Lf）在 37°C 下发酵 48 小时。使用对硝基苯-β-D-吡喃葡萄糖苷作为底物测定β-葡萄糖苷酶活性，并在豆浆中进行水解。在发酵过程中，Lb、Lc、Lp 和 Lf 在 24 小时达到最大生长，La 在 48 小时达到最大生长。多酚含量在 24 小时时为 12.98 至 17.90，在 48 小时时为 12.44 至 15.24mg/100ml。所有乳酸菌都产生β-葡萄糖苷酶，可在发酵豆浆中显著（P<0.05）水解异黄酮糖苷为苷元。
