不同规格虾夷扇贝捕后耐干露特性比较

为探究商品虾夷扇贝规格与其活品耐藏特性之间的关联,对春季上市虾夷扇贝的规格及质量进行分组,再将各组置于4 ℃下湿布覆盖进行3 d冷却干露贮藏,分别于0、1、2 d和3 d采样进行生化代谢指标分析。试验结果显示,市售春季虾夷扇贝依据壳长大致可分成(105.8±1.5) mm、(98.4± 2.3 ) mm及(90.5±1.7) mm 3个规格组,各规格单贝质量相差20~30 g;(98.4±2.3) mm组扇贝的肥满度及闭壳肌出成率较其他两组高,(90.5±1.7) mm组三磷酸腺苷初始含量最高,表明其捕后胁迫耐力好于较大规格扇贝,(90.5±1.7) mm组扇贝同样表现出更好的耐干露特性,干露3 d 三磷酸腺苷含量和核苷酸能荷均明显优于其他两组;糖原含量各组无明显差异。此外,各组扇贝冷却干露2 d后存活率均为100%,干露至第3 d各组开始出现死亡,其中(90.5±1.7) mm组扇贝耐干露特性最好;各组闭壳肌pH与体腔液pH差异不显著;氨基酸分析结果发现,甘氨酸和精氨酸是扇贝闭壳肌游离氨基酸中含量最丰富的氨基酸,其余游离氨基酸变化趋势不明显;体腔液含氮物中,氨含量较高,其余氨基酸含量均较低并在干露期间无明显变化趋势。

Comparison of Air Exposure Stress Resistances of Post-harvested Yesso Scallop with Different Sizes

Biochemical metabolic indices were analyzed in post-harvested yesso scallop Patinopecten yessoensis with shell length of (105.8±1.5) mm (large,L),(98.4±2.3) mm (medium,M) and (90.5± 1.7 ) mm (small,S) covered with wet cloth for 0 d,1 d,2 d and 3 d at 4 ℃ in spring in order to explore the relationship between commercial sizes and live storage stability of yesso scallop. The results showed that medium-sized scallop had obvious advantages over large-sized scallop and small-sized scallop in terms of condition factor and percentage of adductor. The maximal ATP content and high tolerance of air exposure were observed in the small scallop,which had significantly higher level of ATP content and aenylate energy charge (AEC) value than scallop in groups L and M ( P <0.05) when they were kept for 3 d,without significant difference in the glycogen contents in the scallop with various sizes. In addition,survival rate of 100% was found in all sizes of scallop exposed to air for 2 days,and death appeared to be observed in the scallop exposed to air for 3 days,with the highest survival rate in the small scallop. No significant differences in pH values in coelomic fluid and adductor during the post-harvest emersed-storage. The amino acid analysis revealed that there were significantly higher contents of glycine and arginine in the adductor than those of other free amino acids. There was rich in ammonia content in the coelomic fluid,and poor in other amino acid content,even without obvious change during the emersed-storage of the yesso scallop.