Modified Atmosphere Packaging (MAP) on Nutritional Stability and Quality Retention of Oyster Meat (Crassostrea virginica) During Frozen Storage

摘要

The effect of modified atmosphere packaging (MAP) on nutritional stability and quality retention of oyster meat (Crassostrea virginica) during frozen storage was investigated. Fresh oyster meat (300 g) was cryogenically frozen, placed in trays, and film sealed in (1) 100% CO2 (MAP-CO2), (2) 100% N2 (MAP-N2), and (3) 100% air (AIR) followed by 180 days of frozen storage (–20 °C). Oyster meat quality (color, moisture, pH, drip loss, lipid oxidation, and texture) and nutritional stability (amino acid profile and volatile compounds) were evaluated. AIR and MAP-N2 samples showed similar quality parameters after 180 days. In MAP-CO2 samples, oysters’ meat pH decreased due to CO2 absorption, texture increased, and packages collapsed. MAP with CO2 and N2 were effective in reducing lipid oxidation. In all samples, the amino acid composition remained stable, and most of the volatile compounds identified came from the degradation of n-3 polyunsaturated fatty acids. Trimethylamine (seafood spoilage indicator) was not identified in any treatment. This study demonstrated that oyster meat in MAP with high nitrogen content maintained its freshness and quality during frozen storage.