Effects of microbiota dynamics on the color stability of chilled beef steaks stored in high oxygen and carbon monoxide packaging

The microbiota influence on meat color stability of chilled beef steaks under two modified atmosphere packaging (MAP) systems was studied: HiOx-MAP (80% O-2/20% CO2) and CO-MAP (0.4% CO/30% CO2/69.6% N-2). Steaks were stored for up to 20 days at 2 degrees C. Headspace gas composition and color stability were evaluated. High-throughput sequencing analyses were performed to characterize bacterial community dynamics. For HiOx-MAP steaks, Pseudomonas spp. became the dominant species, and an increased oxygen consumption caused by these bacteria contributed to metmyoglobin (MetMb) formation from day 10. Functional analysis based on 16S rDNA sequencing predicted higher abundance of genes related to amino acid and lipid metabolism in HiOx-MAP bacterial communities compared to CO-MAP bacterial communities, which probably accelerated meat discoloration. Lactic acid bacteria dominated in CO-MAP steaks, in which Lactobacillus spp. and Lactococcus spp. contributed to improve redness and chroma, and reduce MetMb%, respectively. These findings help our understanding of color stability in CO-MAP steaks in comparison to HiOx-MAP steaks as influenced by the microbial community.