Isolation and Purification of Chickpea (Cicer arietinum) Seeds Protein, Testing Their Antibacterial Activity, and Using to Extend The Shelf Life of Beef Patties

Abstract

Antimicrobial proteins (AMP) from chickpea (Cicer arietinum L.) seeds were isolated and purified using the saturation of (NH4)2So4 by 80% and gel filtration through Sephacryl S-200, the inhibition zone of the separated peak was 24, and 22 mm for growth of Escherichia coli and Salmonella typhimurium respectively. The molecular mass was 28385 Da estimated through Sephacryl S-200. The optimum pH for activity was 5.5. It was stable at 4.5-7.5, while it lost 21.07 and 55.65% from its activity at pH 3 and 8 respectively, the optimum temperature for activity was 35°C and it was stable at 35°C for 60 min, while it lost all inhibitory activity at 65°C for the same time. The use of AMP at 100 mg resulted in an inhibition zone of 37± 2.92, 35±1.68, 32±2.33, and 33±2.09 mm, with a significant difference at (P≤0.05) against E. coli and S. Typhimurium, Staphylococcus aureus, and Bacillus cereus, respectively. The use of AMP to extend the shelf life of beef patties at 100 mg.kg-1 resulted in a decrease in the total count of bacteria, as it reached 7.4×102±0.18, 4.6×102±0.22 and 2.8×102±0.19 CFU.g-1, while it was 7.4×102±0.23, 8.2×102±0.31, and 9.5×102±0.27 CFU.g-1 in the control sample during a storage period of 0, 3, and 6 d at 4°C. It was observed that there was no significant difference in the control treatment and AMP added on 0 d, while a significant difference was observed at (P≤0.05) for treatments at a storage period of 3 and 6 d at 4°C.