冻结及冻藏温度对小龙虾品质的影响

Effect of Frozen and Freezing Storage Temperatures on the Quality of Red Swamp Crawfish

为探究冻结及冻藏温度对小龙虾品质的影响,将小龙虾热烫后置真空包装盒内,灌水并抽成真空,分别于3个冻结温度(-20,-40和-55℃)的冰柜内冻结至中心温度为-15℃,再置于2个冻藏温度(-20,-40℃)的冰柜中冻藏24周,测定小龙虾的汁液流失率、持水率、剪切力、pH值、TVB-N值、水分状态和肌肉组织的显微结构。结果表明:-20℃与-40℃和-55℃两种冻结温度的小龙虾肌肉组织对比,其肌纤维被破坏程度较轻,虾肉持水率较高,汁液流失率、剪切力、pH值、TVB-N值较低。与-40℃相比,在-20℃冻藏的小龙虾的肌纤维完整性较低,孔隙较大,结构从紧密变成松散,虾肉的持水率、结合水和不易流动水含量较低,汁液流失率、剪切力、自由水含量、pH值和TVB-N值均较高。结论:冻结及冻藏温度影响小龙虾的品质。

The red swamp crawfish preboiled were placed in the plastic box filled with water,then the boxes with crawfish were vacuumed,followed that the crawfish were frozen in the ice locker at-20,-40,and-55℃,respectively.After the center temperature of which were-15℃,the frozen crawfish in boxes were stored at-20 and-40℃for 24 weeks.Juice leakage,water holding capacity(WHC),shearing force,pH value,TVB-N value,moisture state,and myofibrillar microstructure were measured to investigate the changes in quality attributes of red swamp crawfish during freezing storage,and the effect of frozen and freezing storage temperatures on quality attributes.The results showed that,compared with-20℃,muscle fibers of red swamp crayfish frozen at-40℃and-55℃are more slightly damaged,and the crayfish meat has higher juice leakage,lower shearing force,pH value,and TVB-N value and WHC.Compared with-40℃,the muscle fibers of red swamp crayfish stored at-20℃has weaker integrity,and the muscle structure is changed from compact to loose.In addition,the crayfish meat has higher juice leakage,shearing force,pH value,and TVB-N value as well as lower WHC and percentage of bound water and immobilized water.These results indicate that the quality attributes of red swamp crayfish were affected by frozen and freezing storage temperatures,which may provide scientific guidance for the supply of red swamp crayfish throughout the year.