Effect of icing time on the quality of shrimp (Litopenaeus vannamei)

Shrimp is one of the highspoilage seafood that keeping its quality after harvesting is the most important problems to aquatic product industry. The aim of this study is to evaluate the effect of icing on the quality and shelf lifeof Litopenaeus vannamei. After harvesting, shrimp was dipped in sodium metabisulphite solution. Then, divided in immediately icing and 2 hours delay icing treatments. Microbial (MBC, PTC), chemical parameters (PV, TBA, TVB-N) and sensory analysis were measured at 0, 3, 6, 9, 12 and 15 days. The psycrotrophic bacteria and mesophilic counts of 2 hours delay were more than those of the immediately treatment. The mesophilic counts were more than psycrotrophic bacteria in the first days of storage but the psycrotrophic bacteria more increase in comparison to mesophilic during storage. Chemical parameters of immediately icing treatments had a slower growth than the 2 hours delay. Sensory index reduced during storage. Results of this research show that immediately icing was significantly effect on shelf life of Litopenaeus vannamei. Then the shelf life of shrimp was 9 and 12 days in 2 hours delay and immediately treatments respectively.