Inhibition of Listeria monocytogenes and Aeromonas hydrophila by plant extracts in refrigerated cooked beef

Refrigerated ready-to-eat foods are becoming increasingly popular but are often vulnerable to contamination and subsequent growth by psychrotrophic foodborne pathogens. Consequently, there is a need for additional methods to assure the safety of these foods. Beef slices prepared from roasted whole sirloin tips were used in the study. Nine plant extracts were evaluated for ability to inhibit the growth of two psychrotrophic pathogens (Aeromonas hydrophila and Listeria monocytogenes) in refrigerated cooked beef. Results indicated that only eugenol (clove extract) and pimento extract significantly inhibited the growth of A. hydrophila and L. monocytogenes. However, L. monocytogenes was not as sensitive as was A. hydrophila to both treatments, especially to pimento extract. These results suggest that plant extracts might be useful as an antimicrobial in cooked ready-to-eat meat.