Preparation Of Seasoning Based On River Crab Segmentation Processed Products

River crab,also called Chinese mitten crab(Eriocheir sinensis),is one of the important freshwater aquaculture economic crabs in China.It is not only delicious but also of high nutritional value,which is deeply favored by consumers.However,fresh river crabs cannot be supplied to the market for a long time due to the limitation of growing season and lifespan.Therefore,during the market season of river crabs,some small-sized river crabs are segmented and processed into quick-frozen products such as crab claws,crab legs,crab meat,and scraps.At present,the utilization of these quick-frozen products is relatively single,especially scraps and crab meat.With the improvement of people's living standards,nutritious and delicious natural aquatic condiments are being favored by consumers.Therefore,the new-type aquatic condiments by using the segmentation processed products can not only increase the added value of the river crab products,but also open up a new path for the comprehensive utilization of river crab segmented-processed products.Firstly,the nutritional quality of frozen river crab scraps and frozen crab meat were evaluated.Secondly,taking frozen river crab scraps as the raw materials,a new aquatic condiment,namely river crab sauce,was developed through proteolysis and Maillard reaction flavouring technology,and its preparation process was optimized by orthogonal experiments.Thirdly,using frozen crab meat as the raw material,a flavor crab meat sauce with high taste and high nutritional value was developed combining with traditional soybean paste,and its preparation process was optimized by using response surface optimization experiments.Finally,the shelf lives of the two new condiments were predicted by rapid food testing methods.The results are as follows:(1)Frozen crab scraps contain higher fat and protein,with a fat content of 9.74%and a protein content of 13.80%.Fat contains a variety of unsaturated fatty acids that are beneficial to human health,with high nutritional and medicinal values.The protein have a wide range of amino acids,among which the content of umami amino acids is rich.Frozen crab meat is a typical high-protein and low-fat food with a protein content of up to 16.84%.The proportion of essential amino acids and non-essential amino acids in protein is close to the ideal protein model recommended by WHO / FAO,which can well meet the needs of human body.In addition,frozen river crab scraps and frozen crab meat are rich in macro elements and some trace elements,which are necessary for the human body.In general,frozen river crab scrapsand frozen crab meat have high nutritional value and are worthy of further development and utilization.(2)The preparation process of river crab sauce was designed,and the enzymatic hydrolysis conditions of river crab scraps were optimized by single factor and orthogonal experiments.The optimum enzymolysis conditions of river crab scraps were: enzyme content is 650 U/g,reaction temperature is 45?,p H is 10.5,solid-to-liquid ratio is 1: 4,and reaction time is 4 h.Then the sensory score was used as an indicator,and the preparation process was optimized by single factor and orthogonal experiments.The optimum preparation process of river crab sauce was determined as follows: 100 m L of Maillard reaction solution(containing amino acid nitrogen 0.532 g),7% MSG,6% salt,7% white sugar,0.05% I+G,2.5% starch,0.2%carrageenan,2% cooking wine and 0.1% caramel color(the ingredients are all added on the basis of Maillard reaction solution,according to the proportion of reaction solution).The sensory,physicochemical,and hygienic indexes of the crab sauce were initially established,and the product was found to meet the relevant standards through analysis.(3)Combining crab meat with traditional soybean paste,the technological process of flavored crab meat sauce was designed,and the processing technology was further optimized by single factor and response surface experiments.The optimum formula of flavored crab meat sauce was determined as 1: 4.38 main material ratio,6.31% white sugar,6.86% millet pepper and 41.41% vegetable oil.The sensory,physicochemical,and hygienic indexes of the crab meat sauce were initially established,and the product was found to meet the relevant standards through analysis.At the same time,the effects of different sterilization methods on the sensory quality of crab meat sauce were studied.The results showed that ultrasonic and high temperature sterilization reduced the hardness and viscosity of crab meat sauce,while pasteurization and microwave sterilization could maintain the original texture of crab meat sauce.Microwave and high-temperature sterilization significantly reduced the color and sensory score of crab meat sauce,while pasteurization and ultrasonic sterilization could well maintain the original color and sensory score of crab meat sauce.Therefore,pasteurization and ultrasonic sterilization can effectively maintain the original sensory quality of crab meat sauce.(4)During storage at 37?,45? and 55?,the main factors affecting the shelf lives of the two new condiments are different.During the storage of river crab sauce,due to the action of a small amount of microorganisms,amino acids in the system are decomposed to generate TVB-N.Therefore,using the TVB-N content in the crab sauce as an indicator,the shelf life was predicted by the mathematical model,and finally the shelf life of the crab sauce was 185 days.Flavored crab meat sauce has a large amount of vegetable oil added during the production process,so the oxidation of grease is an important factor affecting the shelf life of crab meat sauce.Using the AV and POV as indicators,the shelf life of the flavored crab meat sauce was predicted by the mathematical model,and the shelf life of the flavored crab meat sauce was 261 days.