Plant proteases and anti-bacterial substances in Allium sativum L. varieties

Allium sativum L. protease still remains largely understudied although new varieties of garlic appear quite often, e.g., lanang garlic. This study tested the antibacterial effect of garlic and the effectiveness of various A. sativum proteases as meat tenderizers. The research involved powder extracts of four varieties of A. sativum: kating, lanang, black garlic, and sin-chung. The degradation kinetics was defined based on the Lineweaver-Burk equation. The degradation zones were measured using sodium dodecyl sulphate poly acrylamide gel electrophoresis (SDS-PAGE). Scan electron microscopy served to test the changes in meat connective tissue. Lanang demonstrated the largest inhibition zones against Escherichia coli (9.75 ± 0.15 mm) and Staphylococcus aureus (1.04 mm). Sin-chung protease degraded beef protein with the highest Vmax of 0.1818 μg/μL/min at 10–22 KDa (small peptide, troponin C, and troponin I), 25–40 KDa (myosin light chain, troponin T, α- and β-tropomyosin, actin), and 100–140 KDa (protein C). The same garlic variety degraded mutton meat protein at 10–17 KDa (small peptide) and 25–40 KDa (myosin light chain, troponin T, α- and β-tropomyosin, actin) with Vmax of 0.1135 μg/μL/min. All four A. sativum proteases proved to be quite effective meat tenderizers.