Research on quality changes and indicators of Pandalus borealis stored under different cooling conditions

The quality changes of Northern shrimp, Pandalus borealis , stored in ice, liquid- ice or sal-t water mixed with ice, either at ambient temperature of - 1. 5 or 1. 5 e , were evaluated by using sensory assessment, physical methods, chemical and microbial analysis. Storage in liquid ice was more effective than ice or sal-t water mixed with ice, in delaying spo ilage of the shrimp. It was observed that the total volatile nitrogen ( TVB-N) content decreased during the first day in shrimp stored in liquid ice at both - 1. 5bC and 1. 5bC and its formation was further delayed for 3 days in shrimp stored at - 1. 5bC. In other groups the TVB-N content increased w ith time. The trimethylamine ( TMA) value increased gradually with storage time, in all samples, except for the one stored in liquid ice at - 1. 5e during the first day of storage. Total viable counts ( TVC) showed that bacteria grew most quickly in shrimp stored in ice and in sal-t water ice, followed by those in liquid ice at 1. 5 e or - 1. 5 e respectively throughout the storage period. Lowest counts were observed in sample stored in liquid ice at - 1. 5e where the lag phase of growth of bacteria was apparently extended at the beginning of storage. Principal component analysis ( PCA) and analysis of variance ( ANOVA) were performed to analyse the variation and correlation of indicators. The results show good correlation between some of the quality indicators, TVB-N, TMA, TVC, pH, NH3 response of electronic nose and sensory evaluation.