Effect of freezing on the amino acid profile Changes and some quality index of cultured pacific white shrimp, Litopenaeus vannamei during frozen storage

Effects of frozen (-18°C) storage (6months) on the amino acid profile and sensory quality of pacific white shrimp، Litopenaeus vannamei were investigated. The results indicated that storage in freezing resulted in changes on amino acid profile as essential amino acid significantly decreased (P<0. 05). Regarding non-essential amino acid، change all of them was evident except for Glycine and Tyrosine. Also total amino acid reduction was about 8. 37 percent. The increase in duration caused a decrease in moisture (from 74. 82 to 70. 87%) and increase in drip loss (from 16. 18 to 25. 88) but didn،t change in Atherogenic index (AI) and Thrombogenic index (TI). Significant changes in colour، odour properties and overall of the cocked shrimp were observed but no significantly altered were observed in flavour and tast of them (P>0. 05)، however these products were safe and sensorially acceptable even after 180 days of storage at -18°C.