Effect of Carbon Dioxide Modified Atmosphere Packaging (MAP) for Extension of Shelf-life of Chilled Freshwater Shrimp

This work evaluated the effect of air- and modified atmosphere-packaging (MAP) on the shelf life of chilled freshwater shrimp, which is widely distributed in China and Japan. Freshwater shrimp were stored in air and under modified atmosphere packaging (M1: 80% CO2/20% N2, M2: 50% CO2/50% N2, M3: 30% CO2/70% N2) at 4 ℃ for up to 12 days. Microbiological, physico-chemical, changes in degree of depression and sensory attributes were measured. The results showed that total viable counts (TVC) reached the limiting value (7.0 log CFU/g) after 4, 10, 10 and 8 days of storage under aerobic, M1, M2 and M3 packaging conditions, respectively, while the sensory values (odor) with the trend for TVC. During the storage, the total volatile basic nitrogen (TVB-N) content of chilled freshwater shrimp in MAP packaging was lower than that in air-packaging, especially the M1 and M2 Group. However, the M1 group of modified air box depression significantly higher than the others, affecting the appearance of the product. And the M1 group had the lower elasticity values in comparison with those freshwater shrimp of M2 Group. In conclusion, 50%CO2 concentration packaging prolonged the shelf-life by at least 6 days when stored at 4°C. Our results provide practical information to extend the shelf-life of chilled freshwater shrimp, which will benefit the industry by reducing unnecessary waste.