Study On The Processing Technology Of Refrigerated Prepared Food Of Bighead Carp

The bighead carp is very abundant in China, which has been known as one of the fourmost important freshwater fish. However, the processing utilization rate of bighead carp isvery low and there are some disadvantages of few varieties of processed products and lowyield in the deep processing of fish products. With the accelerating pace of life, prepared foodhas gradually gotten people’s favour, which provides a new research direction for the bigheadcarp’s further processing. Therefore, the processing technology of refrigerated prepared foodof bighead carp was studied in this research to provide theoretical and practical guidance forthe processing and production of bighead carp. The main contents were as follows:In this research, the bacteria-reducing technology was studied. The effects of ClO₂concentration and pretreatment time on the aerobic plate count, color and odor of fish steakwere studied. The results showed that: when treated with40mg/L ClO₂solution for25min,the aerobic plate count of fish steak was reduced by89.3%. Moreover, this treatment had littleinfluence on the quality of fish steak.Secondly, the technology of curing and seasoning was studied. The effects of curingtemperature, salt concentrations, curing time and the liquid solid ratio on the quality of steakwere studied. The results demonstrated that: low temperature was conducive to maintainproduct health conditions. Higher salt concentrations can significantly increase the curing rate,and reduce the curing time. On the other side, the higher salt concentrations can lead to loweramino nitrogen content, and then finally led to bad flavor. The optimal conditions were as thefollowing: the curing temperature,4°C; the salt concentration,8%; the proportion of liquidand solid,3:1; the bloating time,6h. The optimal seasoning recipe was established byorthogonal experiment: monosodium glutamate concentration,1%; powdery capsicumconcentration,0.6%; ginger concentration,1%.Also, the technology of pan-frying was studied. The effects of pan-frying temperatureand time on the quality of fish steak were studied. The results showed that pan-frying processcould significantly improve product quality, hardness, and chewiness, and endow the productwith special flavor and good appearance. The best pan-frying conditions were as follows:each side of fish steak pan-fried5min at180°C. And the effects of pan-frying process onfatty acid composition and volatile flavor compounds were analyzed. The resultsdemonstrated that: the fatty acid composition of fish steak had greatly changed before andafter pan-fried. After pan-frying, saturated fatty acids （SFA）, monounsaturated fatty acids（MUFA） and polyunsaturated fatty acids （PUFA） accounted for23.33%,38.05%and38.54%of the total fatty acids whereas these percentages were15.19%,45.21%and39.56%beforepan-frying. And total53compounds were identified from fried steaks, including23kinds ofhydrocarbons,13kinds of alcohols,7kinds of aldehydes,4kinds of ketones,2kinds of estersand4kinds of heterocyclic compounds. The oxidation and decomposition of lipid andMaillard reaction of protein were the necessary condition for formation of characteristicflavor of pan-frying steak.Lastly, the technology of sterilization was studied. The effects of sterilization conditions on the quality of fried product were studied. The changes of aerobic plate count, TVB-N,TBA, pH, and sensory quality during storage were studied. The best sterilization conditionswere as follows: the sterilization temperature was100°C; the sterilization time was30min.Under these conditions, the production had an attractive color and luster, goluptious flavorand delicious taste. In addition, it could be stored up to49days under4°C, and20days under10°C, meeting the refrigeration prepared food demand.