青虾离水后15℃贮藏温度下品质的变化

The quality change of freshwater shrimp stored at 15 ℃ when get out of the water

综合研究青虾离水15℃贮藏温度下p H、挥发性盐基氮(TVB-N)、脂肪氧化(TBA)值、菌落总数、游离氨基酸值、质构及感官值的变化。结果表明:青虾品质开始下降出现在离水4 h左右,虾肉部位TVB-N含量增加到16.21 mg/100 g,硬度值下降41%,感官值下降到7.1分;离水6 h后青虾品质开始恶化,虾头TVB-N含量为20.13 mg/100 g,菌落总数显著性增加,硬度与弹性显著下降且感观评定得分已小于6.3分,接近腐败级。同时,青虾体内必需氨基酸、鲜味氨基酸及药效氨基酸随贮藏时间延长呈显著性下降趋势。通过综合分析这些指标可得出青虾离水后15℃环境下6 h内加工比较适宜。

The quality parameters of freshwater shrimp stored at 15 ℃ away from water were studied such as p H,total volatile basic nitrogen（ TVB-N）,lipid oxidation（ TBA）,total number of colonies,free amino acid values,texture and sensory score.The results showed that the quality of shrimp began to decline at about 4 h,with the TVB-N value of the shrimp head increased to16.21 mg/100 g,hardness value dropped to 41% and sensory score dropped to 7.1. After 6 h the shrimp quality began to deteriorate,TVB-N of shrimp head was 20.13 mg/100 g,the total number of colonies was increased,hardness and elasticity decreased and sensory score dropped to below 6.3 points,which indicated the shrimp was almost rotten. At the same time,the content of essential amino acids,flavor amino acids and effective amino acids in shrimp meat decreased significantly with prolonged storage time.From these comprehensive index,it can be conjectured that shrimp should be processed within 6 h after getting out of the water at the temperature of 15 ℃.