Bioactive property of soymilk fermented by agrowastes‐immobilized lactobacilli

Abstract

PurposeThis study aims to evaluate the effect of cell immobilization on bioactive property of lactobacilli‐fermented soymilk.Design/methodology/approachAgrowastes from durian (Durio zibethinus), cempedak (Artocarpus champeden), and mangosteen (Garcinia mangostana) were used as immobilizers for lactobacilli (Lactobacillus acidophilus FTDC 1331, L. acidophilus FTDC 2631, L. acidophilus FTDC 2333, L. acidophilus FTDC 1733, and L. bulgaricus FTCC 0411) in soymilk fermentation. Fermented soymilk was stored at different temperatures (4°C, 25°C and 37°C) for 168 h and sampled for analyses periodically.FindingsScanning electron micrographs showed that cells of lactobacilli were immobilized onto the matrix of agrowastes powder. The proteolytic activity was higher in soymilk supplemented with immobilized lactobacilli at 37°C and 25°C compared to that at 4°C. Soymilk fermented by cells immobilized on cempedak rind powder showed higher proteolytic activity (p<0.0001), followed by durian and mangosteen rinds powder (p<0.001). The highest ACE inhibitory activity was also found in soymilk fermented by cells immobilized on cempedak rind powder for all temperatures studied (p<0.0001). In addition, ACE inhibitory activity was higher in soymilk fermented at 37°C, compared to 25°C and 4°C (p<0.0001).Originality/valueThe results in the paper show that cell immobilization enhances the bioactive property of fermented soymilk, in terms of proteolysis and in‐vitro ACE inhibitory activity.