Study On The Processing Technology Of Instant Fresh Water Fish Products

Ctenopharyngodon idellus is the highest yield freshwater fish in China and one of the "four great fish".Grass carp has high protein content,low fat content,high unsaturated fatty acid content,and is not affected by seasonality,so it is popular with consumers.In China,although the yield of fresh water fish represented by grass carp is high,the processing rate is not high,and most of them are sold directly.Therefore,the research on the processing and production mode and product development of freshwater fish has become an inevitable trend to increase the added value of freshwater fish.In this paper,the effects of four kinds of pickling methods on the quality of grass carp were compared,and two pickling methods with fast pickling speed,high nutrition and safety quality were selected.Then four drying methods were used to dry the salted fish,and the effects of different drying methods on the quality of different salted grass carp were analyzed.Finally,two kinds of non fried instant fish products were developed by the selected processing technology,and the quality standards and volatile flavor substances of the two kinds of instant fish products were detected and analyzed.The main results are as follows:(1)Dry salting,wet salting,mixed salting and ultrasonic assisted salting were used to pickle grass carp,and the salting rate,basic nutrients,safety quality,sensory quality and other nutrients were analyzed.Among the four curing methods,ultrasonic assisted curing is the fastest.The protein and fat content of dried salted fish was the highest(16.28 g / 100 g,3.03 g / 100 g,respectively),a * value and B * value were larger,but the total color difference was smaller,the hardness and chewability were higher,and the total amount of essential amino acid and free amino acid was the highest(4.02 mg / g,16.28 mg / g,respectively).After ultrasonic assisted salting,the salt content and water content of fish meat were the highest(2.77% and 77.42%,respectively),the p H value,the total number of colonies and TVB-N content were the lowest,the L * value and B *value were higher,the hardness and chewability were the lowest,and the content of high-quality fatty acids(PUFA and n-3 PUFA)were the highest(58.40% and 10.58%,respectively).The performance of wet curing and mixed curing was not obvious.(2)The drying technology of vacuum,hot air,microwave and hot air microwave was used to dry the grass carp,and the drying rate,physical and chemical properties,sensory quality and other nutrients were analyzed.Under the four drying conditions,the drying rate of ultrasonic treated salted fish is the fastest,TBA value is small,hardness,elasticity and chewability are strong,color difference is big.Among the four drying methods,microwave drying is the fastest,taking about 3 hours,followed by combined drying,taking about 7 hours;after microwave drying,TVB-N content is the lowest(less than 30 mg / 100g),followed by combined drying and hot air drying,taking about 30 mg / 100g;after vacuum drying,TBA The results showed that the hardness,elasticity and chewability of salted fish were stronger,the brightness in color was higher,the redness was lower,the hardness,elasticity and chewability of salted fish were worse after vacuum drying,the redness in color was the highest;the high quality fatty acids were the most after vacuum drying,followed by combined drying.The total amount of free amino acids in salted fish was the highest after combined drying.(3)Using grass carp as raw material,two kinds of non fried instant fish products were developed by ultrasonic assisted salting and microwave hot air combined drying.Through single factor experiment and orthogonal experiment,the best ingredient combination of instant flavor pickled peppers and grass carp was obtained: 20% pickled peppers,6% pickled ginger,6% wet pepper,4% white sugar,4% white vinegar,2% salt,8% cooking wine,6% garlic were added in the pickling solution,7% pickled peppers were added after drying,and the best ingredient combination of instant flavor pickled tea flavored and drunk fish was obtained: 15% tea soup,10% liquor,25% were added in the pickling solution %Huadiao,3% salt,0.4% monosodium glutamate,1% Xieyang,3% sugar,6% tea added after drying.Two kinds of ready to eat fish products were confirmed to meet the nutritional and hygienic quality indicators.The composition and content of volatile flavor compounds in the two products are quite different.