Impact of prebiotics on equol production from soymilk isoflavones by two Bifidobacterium species

Abstract

The influence of commercial prebiotics (fructo-oligosaccharides and inulin) and sugars (glucose and sucrose) on enhancing equol production from soymilk isoflavones by Bifidobacterium longum BB536 and Bifidobacterium breve ATCC 15700 was evaluated in vitro . Sterilized soymilk was inoculated with each bacterial species at 37 °C for 48 h. The growth and β-glucosidase enzyme activity for the two Bifidobacterium species in soymilk throughout fermentation were assessed. The highest viable count for B. breve (8.75 log CFU/ml) was reached at 36 h and for B. longum (8.55 log CFU/ml) at 24 h. Both bacterial species displayed β-glucosidase activity. B. breve showed increased enzyme activity (4.126 U) at 36 h, while B. longum exhibited maximum activity (3.935 U) at 24 h of fermentation. Among the prebiotics screened for their effect in isoflavones transformation to equol, inulin delivered the highest effect on equol production. The co-culture of B. longum BB536 and B. breve ATCC15700 in soymilk supplemented with inulin produced the highest level (11.49 mmol/l) of equol at 48 h of fermentation process. Level of daidzin declined whereas that of daidzein increased, and then gradually decreased due to formation of equol when soymilk was fermented using bifidobacterial. This suggests that the nutritional value of soymilk may be increased by increasing bioavailability of the bioactive ingredients. Collectively these data identify probiotics and prebiotic combinations suitable for inclusion in soymilk to enhance equol production.

Effects of different strains fermentation on the sensory and nutritional properties of soy‐based yogurt

“…lactis is an anaerobic bacterium, and studies have shown that anaerobic bacteria were more conducive to the metabolic transformation of soy isoflavone and equol 40 . One study 41 used Bifidobacterium to ferment soy milk and investigated the conversion of isoflavone into equol in the process of fermentation. The findings revealed that the content of soy isoflavone first decreased and then increased, and the content of equol gradually increased in the fermentation process, which matched the findings of the present study.…”

Improve the antioxidant activity and viability of B. longum and B. animalis subsp lactis in fermented soy and almond milk

“…In our study, both B. longum, and B. lacts maintained the viability of 6.9 and 7.4 log cfu/mL during 21 days of storage for both soy and almond milk and their combination. Mustafa et al (2020) found that the growth lactis strain increased TPC. Further decreases in TPC and TFC during the last two weeks of storage suggest degradation of polyphenol by Bifidobacterium.…”

Production of antioxidants through lactic acid fermentation: current developments and outlook

“…The colonic microbiota will conduct further hydroxylation and biotransformation to produce equol (Hsiao et al, 2020). Equol is an isoflavone derivative with estrogenic activity (Mustafa et al, 2020). The increase of antioxidant capacity was related to the change of isoflavone aglycone proportion.…”