Evaluation of antibacterial and antioxidant activities of Sesame (Sesamum indicum) meal protein hydrolysate produced by Bacillus coagulans (IBRC 10807) fermentation

In this research, sesame meal protein hydrolysate (SPH) was obtained from the sesame protein after hydrolysis by Bacillus coagulans. At first, the peptide concentration test was performed at different times to confirm the protease activity of B. coagulans. The chemical composition and total amino acid contents of sesame meal were determined. Fermentation conditions were optimized using response surface methodology (RSM). The results showed DPPH radical scavenging up to 70%, reducing power up to 0.779, and inhibitory activity against Staphylococcus aureus up to 78%, Escherichia coli up to 60%, Listeria monocytogenes up to 80% and Clostridium perfringens up to 85%. The antioxidant activity of the optimal sample was investigated at concentrations ranging from 10 to 50 mg/mL. The results demonstrated that 50 mg/mL of the SPH had the highest antioxidant activity. Analysis of amino acids by HPLC revealed that glutamic acid and glycine had the highest concentrations, and all essential amino acids were detected. SEM analysis showed smaller heterogeneous particles of protein hydrolysate, which confirmed the hydrolysis process during fermentation. FTIR results showed that different functional groups were formed, which confirmed the hydrolysis of sesame protein. Generally, sesame protein can be a good source in the fermentation system by B. coagulans to produce hydrolysate with antimicrobial and antioxidant properties.