The combination of microbiological, biochemical, and quality index methods in quality evaluation of pacific white shrimps (Litopenaeus vannamei) preserved at 0°C

Abstract

In this study, the sensory, microbiological, and biochemical qualities were used to examine the quality of Pacific white shrimps (Litopenaeus vannamei) preserved at 0°C during a 10-day period. The sensory quality was evaluated by a quality index (QI) that resulted from a quality index method (QIM) scheme. Meanwhile, the total viable count (TVC) and K-value were used to assess the microbiological and biochemical qualities of the shrimp. On day 9, the results from TVC and QIM have shown that the shrimp showed signs of spoilage, corresponding to a log CFU/g of 6.4 and a QI of 21.37, which is unacceptable to consumers. The QI increased linearly with storage days therefore the remaining shelf-life of the shrimp was estimated from a linear regression equation. In particular, this study found a linear relationship between QI, K-value, and hypoxanthine content. Furthermore, hypoxanthine itself could be considered as an independent quality index like the K-index. In conclusion, the quality of Pacific white shrimp was categorized into four different classes: excellent, good, acceptable, and moderately acceptable, based on its sensory and biochemical quality indicators.