Improving the quality assessment for Pacific white shrimp (Litopenaeus vannamei) stored at 0 °C

The quality of Pacific white shrimp stored at 0 °C during the 10 days was evaluated by the combination of sensory, microbiological and biochemical measurements. Quality index methods (QIM) have been developed to evaluate sensory attributes of shrimp. Total visible count (TVC), K value, histamine, and pH are used to assess microbiological and biochemical indices. The results of TVC and QIM showed that shrimps showed signs of spoilage (lg cfu = 6.4; quality index (QI) = 21.37), which is unacceptable to consumers on day 9. QI quality score increased linearly with storage days. The remaining shelf life of shrimp was estimated from the linear regression equation. The results have found the linear regression equations between the QI, histamine, K value, and hypoxanthine. In addition, the results also showed that hypoxanthine could be considered as an independent quality index such as the K index. The quality of Pacific white shrimp could be classified into four grades: excellent, good, moderately acceptable, and just acceptable basing on the results of sensory and biochemical evaluation.