Study On Processing Technologies And Shelf Life Of Instant Prawns

The food structure changed from subsistence pattern to flavored, nutritious andconvenient type with the improvement of people’s living standards. Most traditional prawnproducts were fresh, frozen and dried products, etc, which could not be directly consumedand unable to meet modern consumers’ demand for flavors, convenience, etc. In this study,the processing and storage technologies of prawns were optimized by modern foodprocessing technology in order to develop flavored, casual and instant products.Prawn protein was glycosylation-modified with CMC-Na in the experiment. Themodification effect was best on the conditions of5mg/mL CMC-Na,60℃and20min. Theoptimum blanching conditions were determined by orthogonal tests and sensory analysis,which were2.0%salt concentration,1.0%citrate concentration and90s blancing time.The optimum drying conditions, which were60℃and2.5h, were determined bycomparing sample rehydration with sensory evaluation of different drying conditions.The determination point of shelf life were104CFU/g ACC and16.0mg/100g TVB-Naccording to the result of sensory evaluation. At the same time, the first-order kineticequations between ACC, TVB-N and storage time were developed, as well as theArrhenius equations between ACC, TVB-N diversification rate constant and storagetemperature, in order to predict theoretical value of ready-to-eat products of prawns at astorage temperature. The activation energy of reaction was85.19kJ/mol andpre-exponential factor was4.36×1013in ACC Arrhenius equation, which were74.56kJ/moland2.27×1011in TVB-N Arrhenius equation. The accuracy of kinetic model was verified at30、35、40and45℃.The absolute deviation between predictive value and actual value ofACC shelf life were6.45%、2.74%、11.32%and7.41%, which of TVB-N were6.45%、5.40%、11.32%、0. The theoretical shelf life of vacuum-packed instant prawn products wasdetermined as190.44days at20℃storage temperature by ACC Arrhenius extrapolation,which was102.53days at25℃storage temperature.The theoretical shelf life ofvacuum-packed instant prawn products was determined as155.04days at20℃storagetemperature by TVB-N Arrhenius extrapolation, which was93.19days at25℃storagetemperature.