Effects of CO2 on the physicochemical, microbial, and sensory properties of pork patties packaged under optimized O2 levels.

ABSTRACT

The storage quality characteristics of fresh pork patties were investigated under 80% O2 modified atmosphere packaging (MAP8020 = 80% O2/20% CO2) and 40% O2 MAP with various CO2 levels (MAP4020 = 40% O2/20% CO2/40% N2; MAP4040 = 40% O2/40% CO2/20% N2; MAP4060 = 40% O2/60% CO2). Packaged patties were stored for 16 days at 4 °C to monitor their physicochemical (pH, instrumental color, oxidative stability, and fatty acid profile), microbial, and sensorial changes. Results suggested that decreasing O2 levels from 80% to 40% significantly inhibited the lipid oxidation of patties but led to a lower (P < 0.05) color stability. Elevating CO2 levels from 20% to 60% in combination with 40% O2 significantly suppressed bacterial growth and total volatile basic nitrogen production, and thus rendered patties with a better sensory quality and a similar meat color to 80% O2. However, increased CO2 levels promoted lipid oxidation through reducing the antioxidant capacity of patties, which was attributed to a CO2-induced reduction in superoxide dismutase and glutathione peroxidase activities during storage rather than a pH reduction or changes in fatty acid composition. Overall, 40% O2/40% CO2/20% N2 is a realistic alternative for pork patties to improve meat quality and extend the shelf-life to over 16 days.