Effects of freeze and frozen storage on changes of quality of Eriocheir sinensis

The effect of freeze and frozen storage on Eriocheir sinensis was studied by evaluation of the characteristics of protein,the contents of free amino acids and flavor nucleotides,the activity of Ca²⁺-ATPase and the thawing loss rate.The results showed that E.sinensis had freeze resistance but no frozen storage resistance and the elasticity decreased after 2 weeks' frozen storage.The contents of free amino acids and flavor nucleotides,the activity of Ca²⁺-ATPase and the thawing loss rate changed significantly during frozen storage.After frozen storage of 12 weeks,the contents of free amino acids and flavor nucleotides,the activity of Ca²⁺-ATPase decreased by 25.3%,100%,and 41.6% respectively,compared with those of fresh crabs.While the thawing loss rate increased by 9.2%.The high activities of autolytic enzyme and ATP correlative catabolic enzyme accelerated the decomposition of protein and ATP correlatives at common freezing(-20℃).The protein of E.sinensis was easy to be denatured,which resulted in serious protein denaturation and thaw loss of crab meat.The reason that E.sinensis had no frozen storage resistance might have connection with its autolytic enzyme and ATP correlative catabolic enzyme.