Lactobacillus paracasei CD4 as potential indigenous lactic cultures with antioxidative and ACE inhibitory activity in soymilk hydrolysate

The present study evaluates indigenous Lactic acid bacteria (LAB) isolated from different fermented foods for their fermentation efficiency in soymilk generating anti-oxidative and anti-angiotensin-converting enzyme (ACE) activity in soymilk hydrolysate. The efficiency of lactic cultures to ferment soymilk was evaluated by fermenting 100 mL of soymilk with 1% of lactic cultures, incubated for 24 h at 37 °C. The efficiency of fermentation was determined in terms of degree of hydrolysis of soymilk which ranged from 7.17 to 11.09% for different cultures. Further, the fermented hydrolysate fraction was evaluated for its free radical scavenging activity and ACE inhibitory activity. The fermented soymilk hydrolysate from Lactobacillus rhamnosus GG, Brevibacilllus aydinogluensis, Brevibacillus thermoruber resulted in higher free radical scavenging activity ranging from 62 to 67% as compared to unfermented control (18.4%). However, ACE inhibitory activity was observed only in the hydrolysate from the strains of Lactobacillus paracasei CD4 and B. thermoruber HM34. The principal component analysis of the antioxidative properties of different cultures indicated that the release of total phenolic content and increase in free radical scavenging activity is strain specific.