Use of Lysozyme, Nisin, and EDTA Combined Treatments for Maintaining Quality of Packed Ostrich Patties

Abstract

The antimicrobial effectiveness of lysozyme, nisin, and ethylene diamine tetraacetic acid (EDTA) combination treatments (Mix(1): 250 ppm lysozyme, 250 ppm nisin, 5 mM EDTA; Mix(2): 500 ppm lysozyme, 500 ppm nisin, 5 mM EDTA) on bacterial growth of ostrich patties packaged in air, vacuum, and 2 different modified atmospheres (MAP(1): 80% O(2), 20% CO(2); MAP(2): 5% O(2), 30% CO(2), 65% N(2)) was evaluated. Moreover, the lipid oxidation was evaluated as well as color and sensory characteristics. The growth of total viable counts and lactic acid bacteria were strongly inhibited by the antimicrobial treatments in all the running time (Inhibition Index >97%) whereas for Enterobacteriaceae and Pseudomonas spp. lower inhibition indices from 12% to about 28% were observed. The lipid oxidation was more pronounced in the control respect to the treated meat patties. Moreover, the mixture at low concentration of lysozyme and nisin showed the best antioxidative effect. High concentrations of lysozyme and nisin showed the greatest color loss. Also, off-odors for the untreated patties developed faster than the treated samples. Great interest is developing in food bio-preservation, because of the ever-increasing needs to protect consumers' health and to valorize the naturalness and safety of food products.