The Processing Technology Of Wine-lees Fish

The wine-lees carp, one traditional freshwater fishes in china, enjoys wide acceptancedue to its unique taste. Currently, the wine-lees fish on the market commonly use black fish orgrass fish as raw material, and its production cycle was long, more in a workshop manner.The silver carp is one of four traditional freshwater fishes in china and its yield was very large.Because of its fleshy texture and soil smell，the processing rate was kept at low level and thesales was far lag behind other fish species。By using silver carp as wine-lees fish’s rawmaterial, the production’s costs could be effectively reduced and the values of wine-lees fish’sindustrial application could be greatly improved.Firstly, the contents of raw materials for producing wine-lees fish, the silver carp andwine-lees liquid, were analyzed and nutritionally evaluated. The curing process andpre-drying technology were also systematically studied. By using indicators of curing rate,texture and NaNO2contents, the properties of wine-lees fish produced by dry curing andindustrial wet curing were compared. Our results showed that the curing rate of wet curingwas slower than that of dry curing, but the texture of former product was less affected by thecuring and its NaNO2content was less. Based on this result, the wet curing was optimized,and the optimum parameters were as follows: the concentration of curing liquid was15%,solid-liquid ratio of1:1，curing temperature4℃，processing time12h, with the curing end fishsalt content at about6%. By using drying rate and fish color value as indicators, the wine-leespre-drying parameters were determined: hot air drying at60oC for19hours. the pre-dryingend, with the fish water content at about55%.Secondly，the wine-lees process was studied. Buy using reducing sugar, salt content,amino nitrogen, total acid, pH and moisture as indicators, the process of vacuum wine-leestechnology was studied and compared to traditional wine-lees processing. The optimumvacuum wine-lees processing parameters was chosen as follows: processing temperature of15oC, vacuum degree of0.08MPa, and processing time of8days. Compared with traditionalwine-lees technology, the vacuum technology significantly increased the formation ofwine-lees flavor and reduced wine-lees time. By comparing the contents in fish and wine-leesliquid and the analysis of flavor in wine-lees fish, it was found that the vacuum wine-leesincreased the penetration of flavor substances into the fish meat and improve the formation offlavor of win-lees fish.Finally, the preservation of wine-lees fish was studied. The effect of drying temperature,time, fish moisture, and water activity on the texture, flavor substances and sensory qualitywas studied. The second drying technology before sterilization was chosen as follows: coldair drying for14h. By determining the sterilization cure and F-value cure, the sterilizationprocess of wine-lees was chose as follows:121°C high-pressure steam sterilization for13.5min. By using this sterilization process, the bag of product did not inflate after10days ofpreservation, and the sensory quality was well kept. Compared with commercial wine-lees fish product of well-known brand in the market,the product met the standards of wine-lees fish products standard. Furthermore, the NaNO2and salt content of our wine-lees fish product was much lower than that of commercialproduct. Thus, our wine-lees fish was a product of good flavor and good security.