海湾扇贝低温无水保活过程中营养成分和生化特性的变化

Changes in nutrient compositions and biochemical characteristics of bay scallop Argopecten irradians during keep-alive under free water at low temperature

在4℃条件下,采用充氧保湿处理海湾扇贝Argopecten irradians无水保活20 d,测定无水保活过程中海湾扇贝的营养成分、糖原、乳酸含量,以及总挥发性盐基氮（TVB-N）、游离脂肪酸（FFA）、硫代巴比妥酸（TBA）和盐可萃取性蛋白氮（EPN）等指标的变化。结果表明：在低温充氧保湿条件下,随保活时间的延长,海湾扇贝的水分、粗蛋白质和粗脂肪含量略微下降,粗灰分含量上升,但均无显著性差异（P〉0.05）;糖原含量和EPN值呈下降趋势,且在11～20 d的保活过程中均显著降低（P〈0.05）;乳酸含量呈上升趋势,且在11～20 d的保活过程中显著升高（P〈0.05）;TVB-N值呈上升趋势,且在15～20 d的保活过程中显著升高（P〈0.05）,但保活20 d时的TVB-N含量仍低于鲜、冻动物性水产品卫生标准（GB2733—2005）中对海产贝类的TVB-N可接受限0.15 mg/g;FFA、TBA值均呈上升趋势,但上升趋势平缓,变化幅度小,且无显著性差异（P〉0.05）。研究表明,在充氧保湿条件下,低温无水保活20 d的海湾扇贝营养损失和品质风味变化均较小,且保持着良好的鲜活状态。

The changes in levels of glycogen,lactic acid,total volatile basic nitrogen（ TVB-N）,free fatty acid（ FFA）,thiobarbituric acid（ TBA） and salt extractable protein nitrogen（ EPN） were determined in keeping-alive bay scallop Argopecten irradians preserved under conditions of moisture-aerobic treatment（ free water） for 20 d at temperature of 4 ℃. The results showed that moisture,and contents of crude protein and crude fat were decreased slightly,and ash content increased in the keeping-alive bay scallop during free water moisture-aerobic treatment as time elapse,without significant difference（ P〉0. 05）. Both glycogen content and EPN values were found to be significantly decreased during 11-20 d keeping-alive process（ P〈0. 05）. The lactic acid contents,however,were significantly elevated（ P〈0. 05）,especially during 11-20 d keeping-alive process. TVB-N value was shown to be significantly increased during 15-20 d keeping-alive process（ P〈0. 05）,within the acceptable TVB-N threshold（ 0. 15 mg / g） in seafood shellfish in China on the 20 th day of the keeping-alive process. Both FFA and TBA values were shown to be increased gently,without significant difference（ P〉0. 05）. The findings indicated that there were little nutritional loss and changes in quality and flavor,maintaining a good fresh condition,in the keeping-alive bay scallop during free water at low temperature.