The Gel Properties Of Freashwater Fish Surimi Gel And The Changes Of Myofibrillar Protein During Gel Fornation

The production of freshwater fish in China is high nowadays,and the freshwater fish were increasingly popular because of their high quality nutrients.The research on freshwater fish and surimi products had received extensive attention.However,at present,the research of freshwater fish involved fewer orders and species.The orders and species of the freshwater fish started to fossilization,and fish diseases about the current species of the freshwater fish were gradually increasing.The 30 species of freshwater fish were included as research objects,aiming to provide a basis for the development and utilization about new species of freshwater fish,and to provide people with a better source of dietary freshwater fish.Thirty species of freshwater fish in five orders were selected,It contained 12 species of freshwater fish from Cypriniformes,11 species of freshwater fish from Perciformes,4 species of freshwater fish from Siluriformes,2 species of freshwater fish from Acipenseriformes,and 1specie of freshwater fish from Anguilla rostrata?In the Cypriniformes,the freshwater fish of Cyprinus carpio,Carassius auratus,Megalobramaamblycephala,Aristichthys nobilis,Ctenopharyngodon idellus,Hypophthalmichthys molitrix,Cirrhinus Molitorella,Mylopharyngodon piceus,Myxocyprinus asiaticus,Culter alburnus Basilewsky,Aristichthysnobilis were selected.In the Perciformes,the freshwater fish of Lateolabrax japonicus,Lepomis gibbosus,Ophiocephalus argus,Siniperca chuatsi,Oreochromis spp,Scortum barcoo,Perca Fluviatilis,Lucioperca lucioperca,Macculochella peeli,Epinephelussp,Channa maculata were selected.In the Siluriformes,the freshwater fish of Leiocassis longirostris,Ietalurus Punetaus,Silurus asotus,Pelteobagrus fulvidraco were selected.In the Acipenseriformes,the freshwater fish of Polyodonspathala,Polyodon spathula were selected.In the Anguiliformes,the freshwater fish of Anguilla japonica Temminck et Schlegel was selected.After removing the skin of 30 species of freshwater fish,the basic nutrients of fish muscles,including protein,moisture,ash and fat content,were measured.The basic nutrients of muscles in different species and in different orders about the freshwater fish were compared and analyzed.The systemic clustering analysis method was used to systematically evaluate the basic nutrients of 30 species of freshwater fish.The muscle of 30 species of freshwater fish were made into surimi products through salt washing,water washing,beating,low temperature gel,high temperature gel,gel forming and so on.The difference of gel strength between 30 species of freshwater fishsurimi was analyzed.The 30 species of freshwater fish surimi gel characteristics,breeding yield and economic benefits were considered comprehensively,seven species of freshwater fish were selected.The freashwater fish of Ctenopharyngodon idellus,Cirrhinus molitorella,Oreochromis spp,Aristichthys nobilis,Pelteobagrus fulvidraco,Hypophthalmichthys molitrix and Lateolabrax japonicus were included.The gel properties of seven species of freshwater fish surimi in the process of surimi gel were analyzed.The main indicators were gel strength,texture,elasticity,hardness,chewiness,whiteness and water holding capacity.The effect of the preparation process of surimi on the gel properties of surimi had been analyzed.The Myofibrillar proteins of 7species of freshwater fish during the process of surimi were extracted.The changes in disulfide bonds and hydrophobic interactions in myofibrillar proteins during gel formation were measured.The results were as follows:(1)The difference in protein content and ash content between the five different orders of freshwater fishes was statistically significant.The difference in water content and fat content between the five different orders of freshwater fish was not statistically significant.The protein content in the Perciformes and in the Anguilla rostrata was higher than that of the Cypriniformes,the Siluriformes and the Acipenseriformes.The ash content in the Cypriniformes was higher than that of thePerciformes,the Siluriformesthe and the Anguilla rostrata.There was no significant difference in the ash content between the Cypriniformes and the Acipenseriformes.The protein,moisture,ash and fat contents of the12 species of freshwater fish in the Cypriniformes were16.65~20.26g/100 g,73.29~78.67g/100 g,0.08~3.597g/100 g,1.19~6.08g/100 g,respectively.The protein,moisture,ash and fat content of the 11 species of freshwater fish in the Perciformes were 17.25~20.31g/100 g,65.47~75.95g/100 g,0.77~1.65g/100 g,0.10~13.02g/100 g,respectively.The protein,moisture,ash and fat contents of the 4 species of freshwater fish in the Siluriformes were 15.80~19.39g/100 g,67.60~77.89g/100 g,1.06~1.329g/100 g and 1.66~5.94g/100 g,respectively.The protein,moisture,ash and fat contents of the 2 species of freshwater fish in the Acipenseriformes were 17.77~17.80g/100 g,67.26~77.13g/100 g,1.05~1.40g/100 g,3.67~3.70g/100 g,respectively.The30 species of freshwater fish were clustered into 3 categories by cluster analysis.The first type was Oreochromis spp,Lucioperca lucioperca,Polyodon spathula,Pelteobagrus fulvidraco,Cyprinus carpio,Megalobrama amblycephala,Leiocassis longirostris,Ctenopharyngodon idellus,Culter alburnus Basilewsky,Mylopharyngodon piceus,Anguilla japonica Temminck et Schlegel,Channa maculata,Carassius auratus,Aristichthys nobilis,Ctenopharyngodon idellus,Lateolabrax japonicus,Lepomis gibbosus,Percafluviatilis,Aristichthysnobilis,Cirrhinus molitorella,Ietalurus Punetaus,Hypophthalmichthys molitrix,Myxocyprinus asiaticus,Siniperca chuatsi.The second type was Silurus asotus,Polyodonspathala,Scortum barcoo,Epinephelussp.The third type was Macculochella peeli.The content and proportion of protein,moisture,ash and fat in the same type of freshwater fish were similar.The content and proportion of protein,moisture,ash and fat in different types of freshwater fish were quite different.(2)For the different species of freshwater fish,the same process was used for the surimi products.Among them,the gel strength of 30 freshwater fish gel was between 882.47-6513.35 g.mm.In this experiment,the gel strength of the Ctenopharyngodon idellus,the Ietalurus Punetaus,Siniperca chuatsi were better than other species of freshwater fish,the gel strength of the Pelteobagrus fulvidraco was the lowest.Among the 30 species of freshwater fish,these species of freshwater fish had a gel strength of more than 4000 g.mm,such as Ctenopharyngodon idellus,Ietalurus Punetaus,Siniperca chuatsi,Oreochromis spp and Aristichthysnobilis.The gel strength was between 3000-4000 g.mm,including Ophiocephalus argus,Polyodonspathala,Mylopharyngodon piceus,Scortum barcoo and Anguilla japonica Temminck et Schlegel.There were differences in gel strength between different orders and different species of freshwater fish after the surimi gel forming.(3)The gel strength,hardness,chewiness and whiteness of the 7species of freshwater fish after high temperature gel passing through the the low temperature gel were significantly higher than those of the low temperature gel.The gel strength,hardness,chewiness and cohesiveness of the Oreochromis spp surimi in the low-temperature gel stage and high-temperature gel stage were higher than that of Ctenopharyngodon idellus,Cirrhinus molitorella,Aristichthys nobilis,Pelteobagrus fulvidraco,Hypophthalmichthys molitrix,Lateolabrax japonicus.The whiteness of Ctenopharyngodon idellus was the highest.During the two-step heating stage of the seven species of freshwater fish gel,the differences in gel strength,hardness,elasticity,chewiness and cohesion were statistically significant.In combination with the above indicators,among the above seven species of freshwater fish,the Oreochromis spp surimi had the highest quality synthetically.(4)The hydrophobichydrophilic interactions of the seven species of freshwater fish surimi during the gel formation process were significantly increased in the low temperature gel stage and the high temperature gel stage.The difference in hydrophobichydrophilic interactions between the different species of freshwater fish surimi was statistically significant.Among the seven species of freshwater fish surimi,the greater the hydrophobichydrophilic interactions was,the greater the gel strength was.The disulfide bonds increased during the gel(5)formation of the seven species of freshwater fish surimi gel forming,and increased significantly in both the low temperature gel and the high temperature gel stage.