低温液体速冻对软壳三疣梭子蟹冻藏期间肌肉生化特性的影响

Effect of cryogenic liquid quick-freezing on the biochemical properties of soft shell swimming crab( Portunus trituberculatus) muscle during frozen storage

为明确低温液体速冻对软壳三疣梭子蟹的保鲜效果,通过对持水力、pH、TBA值、肌动球蛋白盐溶性、Ca2+-ATPase活性、巯基含量等理化指标的测定,研究了软壳三疣梭子蟹经-25、-35和-50℃液体速冻处理后在-20℃冻藏过程中生化特性的变化情况。结果表明:随着贮藏时间的延长,三个处理组的pH先减小后增大,TBA值持续上升,其他指标皆呈现逐渐下降的趋势,且在贮藏期前60d内肌动球蛋白盐溶性及Ca2+-ATPase活性差异不显著(p>0.05),但之后开始出现显著差异(p<0.05);在贮藏30d后,三个处理组的巯基含量快速下降且差异显著(p<0.05),-25℃处理组极显著低于-50℃处理组(p<0.01)。综合分析各项指标可知液体速冻温度越低,软壳梭子蟹在冻藏过程中肌肉品质下降越小。

In order to confirm the effect of cryogenic liquid quick-freezing on preservation of soft shell swimming crab.The changes of biochemical properties of soft shell swimming crab muscle during the frozen storage period of 90 days at-20℃ with liquid quick-freezing under-25,-35 and-50℃ were studied by measuring the solubility of actomyosin,-SH content, Ca2＋-ATPase activities, WHC, pH value and TBA value.The result indicated that. the solubility of actomyosin,-SH content and Ca2＋-ATPase activities decreased with prolonging of the frozen storage period from the treatment groups;pH decreased＇first and then increased i TBA value ascended persistently;in the first 60 days of the frozen storage period, the solubility of actomyosin and Ca2＋- ATPase had no significant difference（p 〉 0.05） and appeared significant difference later （ p 〈 0.05 ） among the three treatment groups. - SH content declined rapidly and emerged significant difference（p 〈0.05）between the different treatment groups after 30 days.At the same time,the group at-25℃ was lower significantly than the group at-50℃（p 〈0.01 ）.Therefore, the temperature of liquid quick-freezing is lower,the slower deteriorated in soft shell swimming crab muscle.