Influence of hen egg white lysozyme N‐acetylmuramide glycan hydrolase on the antimicrobial activity and textural characteristics of high‐moisture mozzarella cheese

Abstract

This work explored the antimicrobial activity of hen egg white lysozyme N-acetylmuramide Glycan Hydrolase against Escherichia coli, Staphylococcus aureus, yeast and mold. Agar diffusion test (well variant) was used to check the qualitative antimicrobial activity of lysozyme. Moreover, minimum inhibitory concentration was tested using microdilution method. Colony count method was used to test the yeast and mold growth. The results showed that ML4 (0.08% lysozyme) yielded greater zone of inhibition growth (14.3 mm) for S. aureus. However, zone of inhibition growth for E. coli was very small (8.3 mm) for ML4 (0.08%). Moreover, during storage a reduction in E. coli growth was noticed. Lysozyme inhibited the growth of yeast and mold up to 20 days under refrigeration. The lysozyme also significantly influenced the texture parameters of mozzarella cheese. Results support the use of natural preservative hen egg white lysozyme to control the growth of S. aureus, yeast and mold in high-moisture mozzarella cheese. Practical applications The consumers pressure on cheese industry of using natural antimicrobial compounds is increasing day by day. It is due to the negative impact of synthetic preservatives on health and misuse of antibiotics that has resulted in the huge rise of foodborne pathogens that are resistant to antibiotics and several food processing and preservation methods. Lysozyme is an enzyme that can be used in the cheese industry as natural antimicrobial compound. Its application in high fat mozzarella cheese inhibits the growth of Staphylococcus aureus, yeast and mold under refrigeration storage.