The Effect Of Preservation Of Carp Surimi Added Natural Preservatives During Superchilling Storage

In the freshwater fishery in our country, the account for carp surimi has large proportion, and its industry value is very important. At present, there are about95%of freshwater fish with ice or fresh ways to enter into the market. As the content of freshwater fish is high, its freshness drops fast, and spoilage easily after its butcher. Traditional freezing preservation method can make protein denaturation easily, and dry consumption, it will lead to changes in flavor, its commercial value decreases as well. So we need to find a new preservation method to improve its freshness. The object of this work was to improve the preservation of freshwater fish with super-chilled and added natural preservatives, improve its edible quality and thus coextension super-chilling preservation technology, promote the development of fishery. In this experiment, the carp surimi was used as research object, the change of its quality characteristic and myofibrillar protein were researched with mixed natural preservatives. The result were as follows:1. The carp surimi were storaged under4℃and-1℃in the fridge. During20days (4℃storage was only12days), microbiological and physicochemical indicators were investigated to evaluate the effect of preservation every4days. The results showed that, after8days storage, the group of cold storage (4℃) has gone bad, but the group of super-chilling has extend shelf-life to12-16days. At16th day, its total bacterial count was6.69log cfu/g, pH value was6.92, a*value was11.96, TVB-N value was19.45mg/100g, TBARs value was1.12mg/kg. Meanwhile, myofibrillar protein solubility and sulfhydryl group were determined to evaluate the effect of preservation every4days. The results showed that the data of protein of the group of cold storage (4℃) ranged quickly, and the data of protein of the group of super-chilling ranged slowly. But the change of protein changed quickly in the late storage (during16-20days).2. The carp surimi which was added different content chitosan, lysozyme and Vc respectively were storaged at-1℃in the fridge. During20days, microbiological and physical and chemical indicators were investigated to evaluate the effect of preservation every4days. The results showed that with certain increasing amount of preservatives, TVB-N value and TBARs value decreased significantly (P<0.05) compared with the control group. Over this range, the data was increased on the contrary. This showed that natural preservative could delay some extent carp surimi spoilage.3. The carp surimi which added mixed three preservatives were storaged at-1℃in the fridge. During24days, microbiological and physicochemical indicators were investigated to evaluate the effect of preservation every4days. The results showed that the preservatives mixed, the preserving effect was better than any of the single ones (P<0.05). The optimizing ratio was that chitosan was0.97%, lysozyme was0.48%, Vc was0.41%.4. The carp surimi which added optimizing ratio of the three preservatives were storaged under-1℃ in the fridge, its shelf-life could extend to20-24days. At24th day, its total bacterial count was6.33log cfu/g, pH value was6.74, a*value was12.56, TVB-N value was20.58mg/100g, TBARs value was1.06mg/kg. Myofibrillar protein solubility was51.89%, the total sulphur content was54.26umol/g, active sulphur content was1.15%. This can delay the deterioration of carp surimi, so as to the shelf-life, at the same time can gain more economic benefits.