Development of probiotic carriers using microbial transglutaminase-crosslinked soy protein isolate incorporated with agrowastes

Probiotics are live micro-organisms that exert beneficial effects on their host. A high survival rate during gastrointestinal transit and storage is often desirable. The main aim of this study was to develop protective carriers for probiotics via the use of enzymatically crosslinked soy protein isolate incorporated with agrowastes such as banana peel, banana pulp, cempedak rind and cocoa rind.Addition of agrowastes significantly (P < 0.05) reduced the strength and pH and darkened the colour of the gel. Sodium dodecyl sulfate polyacrylamide gel electrophoresis indicated that microbial transglutaminase induced crosslinking in the carrier network, while scanning electron microscopy showed that agrowaste addition resulted in a denser, finer and thinner protein network. Controlled release and swelling tests of the carriers in simulated gastric and intestinal fluids showed a low release under gastric conditions but a high release under intestinal conditions. The viability of Lactobacillus acidophilus FTDC 1331 incorporated in carriers containing agrowastes was more stable during storage at 4 °C for 28 days compared with the control (P < 0.05).The results of this study showed that agrowastes could be utilised as new probiotic carriers for enhanced gastrointestinal transit and storage.