Inter-relationships between the metrics of instrumental meat color and microbial growth during aerobic storage of beef at 4°C

The objective of this study was to investigate the inter-relationships between changes in beef color and microbial growth when steaks from longissimus thoracis et lumborum muscles were overwrapped with polyvinyl chloride film and stored at 4 degrees C. At day 0, 4, 7 and 10 instrumental color (CIE L*, a*, b* and spectral scans) and microbial counts were measured. Bacterial communities were characterized through Terminal Restriction Fragment Length Polymorphism analysis. Both meat discoloration and microbial spoilage occurred at day 10. Total viable count, Enterobacteriaceae count and the relative abundance of Pseudomonas spp. and Acinetobacter spp. were significantly correlated with color metrics associated with discoloration. These findings indicate that meat discoloration and microbial growth may not be totally independent effects and changes in a*, Chroma and hue angle may be an indicator of meat spoilage under this specific storage condition. Meanwhile, Enterobacteriaceae and aerobic bacteria might play important roles in meat discoloration.