Comparison And Study On The Nutritional And Sensory Qualities Of The Mud Crab(Scylla Paramamosain) From Different Sources,Growth Forms And Cooking Methods

Mud crab(Scylla paramamosain)is one of the most important economic crab specie in China.It is more and more popular in customers because of its unique flavor and high nutritional value.However,due to the different geographical and cultural environment,there are some differences in the nutritional quality of mud crabs cultured in those area.In addition,with the further development of the mud crab industry,the basic data supplement for the comprehensive and reasonable evaluation mud crab is actually demands,thus,the research on nutritional quality of mud crab in-depth are urgently.Moreover,the research on the butter crab,which is a special growth form of mud crab,has not been well conducted,the nutritional and sensory quality has not been explored,therefore,the preliminary understanding of the quality of butter crabs are urgently needed.Moreover,the most common method of cooking mud crab is boiling and steaming,while the sensory differences between mud crab cooked with boiling water and steam are rarely reported,thus,the relevant research is need conducted for customers to learn about more information.Firstly,the nutrient compositions of muscle,hepatopancreas,and gonad of three sourced mud crabs from the Bohai Sea,the East China Sea,and the South China Sea were analyzed in paper.Secondly,the sensory qualities were analyzed by sensory evaluation,E-nose,the taste activity value analysis,and volatile compounds analysis.Thirdly,the nutritional and sensory qualities of normal mud crab,precursor butter crab,and butter crab were analyzed preliminarily.Lastly,the sensory qualities of mud crab boiled with cold water,boiled with hot water,steamed with cold water,and steamed with hot water were compared.(1)the mud crabs from three sources all contained high ash contents,and the crude protein contents in muscle of them were all higher than 15%,and the crude protein contents in the gonad were all higher than 25%.The essential amino acid index(EAAIs)in the muscle of female mud crabs from three sources were all higher than 70,while the EAAIs in the muscle of male mud crabs from the East China sea and the South China sea were lower.The EAAIs in the hepatopancreas of mud crab from the Bohai sea and the South China sea were all higher than 60,while the EAAI in the hepatopancreas of female mud crab from the East China sea was less than 60.Meanwhile,the EAAI in the gonad of three sourced mud crabs were all higher than 70.The minerals contents in three sourced mud crabs were all abundant,moreover,the muscle and hepatopancreas of three sourced female mud crabs showed higher Zn content.The muscle and gonad tissue showed higher EPA,DHA,and polyunsaturated fatty acids(PUFA)content,while the EPA,DHA,and PUFA content in the hepatopancreas were lower than those of in the muscle and gonad.By comprehensive analysis,it can be concluded that the muscle of mud crabs from the Bohai sea and the East China sea,the hepatopancreas of mud crabs from Bohai sea,the gonad of the male mud crabs from the East China sea,and the gonad of the female mud crabs from the Bohai sea and the East China sea have better nutritional value.In summary,the nutritional quality of mud crab from the Bohai sea were relatively better.(2)The TAV analysis showed that the taste of muscle was sweet,and the major sources of the sweetness were Arg,Gly and Ala.The sweet and umami are the dominant taste of the hepatopancreas,the major source of the umami was Glu,and the major sources of the sweetness were Ala and Arg.Moreover,the taste of the sweet and umami in the gonad were also strong,the major source of the umami was also Glu,and the major source of the sweetness was Arg.The sum of the first and second principal components of muscle,hepatopancreas and gonad are all higher than 90%.Aldehydes were the major flavor sources in the edible tissues of mud crab,and many aldehydes were all presented in the edible tissues of the three sourced mud crabs.In addition,several unsaturated aldehydes were showed in the hepatopancreas,which resulted in the flavor of the hepatopancreas were more relatively unique.By comprehensive analysis,it can be concluded that the muscle of male mud crabs from the Bohai sea and the East China sea,the muscle of female mud crabs from the South China sea,the hepatopancreas of the male and female mud crabs from the East China sea,the gonad of male mud crabs from the Bohai sea,and the gonad of female mud crabs from the South China sea have better sensory quality.In summary,the overall sensory quality of mud crab from the Bohai sea and the East China sea were better.(3)The butter crab is a special growth form of mud crab without gonad.The edible tissues of normal mud crab,precursor butter crab,and butter crab all contained high ash and crude protein,and the crude fat contents in the hepatopancreas and gonad of three growth forms mud crab were all high.The essential amino acid contents and the EAAI in the muscle and hepatopancreas were higher than those of precursor butter and normal mod crab,while the essential amino acids content and the EAAI in the gonad of normal mud crab were higher than those of in precursor butter crab and butter crab.The mud crabs in three growth forms were all contained high minerals,and all of them could be considered as good mineral sources for consumption.The TAV analysis displayed that the dominant taste of muscle was sweetness,and the major source of sweetness from the free amino acid was Gly,Arg and Ala.The dominant taste of the hepatopancreas and gonad was sweet and umami,Glu contributed to the major umami taste,and Ala contributed to the major sweetness.The flavor of precursor butter crab and butter crab was better.In summary,the gonad of normal crab,and the muscle and hepatopancreas of precursor butter crab and butter crab had better nutritional quality.Moreover,the flavor of precursor butter crab and butter crab was better.(4)The sensory analysis of mud crab steamed with hot water,boiled with hot water,steamed with cold water,and boiled with cold water showed that the taste of muscle was sweetness,and the major source of sweetness in muscle were Arg,Gly and Ala.The sweetness and umami were the dominant taste of hepatopancreas,the major source of the umami from free amino acid was Glu,the major source of sweetness was Arg,and the major source of bitterness was Val.Moreover,the dominant taste in the gonad of male mud crab was umami,and that in female was sweet,the major source of umami was also Glu,the major source of the sweetness was Arg and Ala,and the major source of bitter was Lys and His.The sum of the first and second principal components in the mud crab cooked in four methods was all higher than 90%.The volatile compound analysis indicated that the major flavor source of the mud crab cooked in four methods was not only aldehydes,but N-containing compounds may also contribute to flavor.By comprehensive analysis,it can be concluded that the sensory quality of the male mud crab muscle steamed with cold water,the female mud crab muscle steamed with hot water,the male mud crab hepatopancreas steamed with cold water,the female mud crab hepatopancreas steamed with cold and hot water,and the male and female mud crab gonad steamed with cold water were better.In summary,the sensory quality of the mud crab steamed with cold water were better.