EFFECTS OF ZIZIPHORA CLINOPODIOIDES ESSENTIAL OIL AND NISIN, BOTH SEPARATELY AND IN COMBINATION, TO EXTEND SHELF LIFE AND CONTROL ESCHERICHIA COLI O157:H7 AND STAPHYLOCOCCUS AUREUS IN RAW BEEF PATTY DURING REFRIGERATED STORAGE

摘要

The effect of Ziziphora clinopodioides (0.1 and 0.2%) and nisin (250 and 500IU/g), both separately and in combination, on mesophilic, psychrotrophic and Enterobacteriaceae microorganisms and also on Staphylococcus aureus and Escherichia coliO157:H7 in raw beef patty during storage at refrigerated temperature for 9 days were evaluated. Carvacrol (64.22%), followed by thymol (19.22%), p-cymene (4.86%) and -terpinene (4.63%) were the most abundant components of the essential oil. Both the essential oil and nisin significantly (P0.05) affected the growth of psychrotrophic, Enterobacteriaceae and mesophilic bacteria and also S.aureus and E.coli O157:H7. Among the experimental groups, samples treated with 0.2% essential oil+500IU/g nisin showed the significant most rapid decrease (P0.05) in the number of tested microorganisms. Our findings indicate that the essential oil of Z.clinopodioides and nisin has a potential to be applied as an antimicrobial and preservative agent in food products, especially in beef patty.