Quality changes of shrimp (Pandalus borealis) stored under different cooling conditions

The influence of different cooling techniques and storage temperatures (-1.5 degrees C or 1.5 degrees C) to prolong the shelf life of shrimp was evaluated by semsory analysis, physical methods, chemical analysis, and microbial analysis. Storage in liquid was more effective than flake ice or brine mixed with flake ice in delaying spoilage of the shrimp by slowing down microbial growth and formation of total volatile basic nitrogen (TVB-N) and trimethylamine (TMA). Total viable counts (TVC) showed that bacteria grew most quickly in shrimp stored in flake ice and in brine mixed with falke ice, followed by those in liquid ice at 15 degrees C and -1.5 degrees C, respectively. Lowest counts were observed in shrimp stored in liquid ice at -1.5 degrees C where the lag phase of growth was apparently ectended at the beggining of storage. Principal component analysis (PCA) showed a good correlation between quality indicators related to microbial growth, TVC, pH, TVB-N, TMA, responses of an electronic nose and sensory evaluation.