The investigation on the anti-bacterial power of bioactive peptides obtained from enzymatic hydrolysis of pumpkin (Cucurbita pepo) oil cake protein

Nowadays a large part of microorganisms are going to become resistant against common antibiotics. In this study the effect of bioactive peptides obtained from enzymatic hydrolysis of pumpkin oil cake protein as natural anti-microbial agents was examined. In this research pumpkin (Cucurbita pepo) oil cake protein was hydrolyzed by pepsin, trypsin and alcalase. Optimum treatments were selected based on DPPH radical scavenging activity and anti-microbial activity of total and diluted extracts (1/2, 1/4, 1/8 and 1/16) were evaluated against Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus and Escherichia coli. peptides produced by 1% pepsin, 30 ˚C and 2h hydrolysis (P3012), 1% pepsin, 35 ˚C, 3.5h hydrolysis (P35135), 1% alcalase, 50 ˚C, 3.5h hydrolysis (A50135), 2% alcalase 50 ˚C, 3.5h hydrolysis (A50235), 1% trypsin, 35 ˚C, 5h hydrolysis (T3551) and 1% trypsin, 45 ˚C and 5h hydrolysis (T4551) were selected as optimum treatments. Total extracts of P3012, T4551 and A50135 showed an appropriate inhibitory effect on tested bacteria while total extract of T3551 had no inhibitory activity against pathogens. The minimum inhibitory concentration of P35135 was 1/2­ against Bacillus, 1/8­ against Escherichia and 1/16 against Listeria. Minimum inhibitory concentration of A50235 was 1/4 on Staphylococcus and Bacillus and1/8 against Listeria. Based on the results, enzymatic hydrolysis can be employed as an effective approach to produce natural anti-oxidative and anti-microbial agents.