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

The storage quality characteristics of fresh pork patties were investigated under 80% O 2 modified atmosphere packaging (MAP80:20 = 80% O 2 /20% CO 2) and 40% O 2 MAP with various CO 2 levels (MAP40:20 = 40% O 2 /20% CO 2 /40% N 2 ; MAP40:40 = 40% O 2 /40% CO 2 /20% N 2 ; MAP40:60 = 40% O 2 /60% CO 2). 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 O 2 levels from 80% to 40% significantly inhibited the lipid oxidation of patties but led to a lower (P < 0.05) color stability. Elevating CO 2 levels from 20% to 60% in combination with 40% O 2 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% O 2. However, increased CO 2 levels promoted lipid oxidation through reducing the antioxidant capacity of patties, which was attributed to a CO 2 -induced reduction in superoxide dismutase and glutathione peroxidase activities during storage rather than a pH reduction or changes in fatty acid composition. Overall, 40% O 2 /40% CO 2 /20% N 2 is a realistic alternative for pork patties to improve meat quality and extend the shelf-life to over 16 days. • The quality of pork patties was explored under HiOx-MAP with various CO 2 levels. • 40% O 2 combined with 40–60% CO 2 gave patties a similar color to 80% O 2 /20% O 2. • High levels of CO 2 promoted the lipid oxidation of HiOx-MAP pork patties. • CO 2 reduced superoxide dismutase and glutathione peroxidase activities in patties. [ABSTRACT FROM AUTHOR]