Study On Improvement Of Functional Properties Of Silver Carp Myofibril Proteins By Soy Protein Isolate

With the rapid development of aquaculture production, freshwater fish processing lagphenomenon became a bottleneck of affecting the development of freshwater fisheries. Thetopics are on how to improve the characteristics of myofibrillar protein (MPI) of low-valuefreshwater fish-silver carp. Soy protein isolate (SPI), as one of functional food additives withwide range of applications, after heat treatment, transglutaminase treatment, mixed withmyofibrillar protein.By studying the changes in the gel properties to find the best gellingparameters, to give full play of auxiliary and improve of SPI to protein gel properties. The resultsof this paper are valuable for reasonable use of SPI and improving the quality of surimi-basedproducts. This study consists of three parts:Chapter I. By different denaturation temperature and denaturation time, SPI was mixed withMPI in different ratio to prepare heat induced gel. By measuring the gel strength, water-holdingcapacity and rheological properties of the mixed-protein system, to analysis the effect of thermaldenaturation soy protein isolate to mixed gel properties. The results show the soy protein isolatewith thermal denaturation can not only improve the gel strength and water-holding capacity ofthe hybrid protein gel system, but also can improve modulus of elasticity. Among, after SPI isdenatured at100℃for180min, two mixed with one to four to get the best mixed gel strengthand water-holding capacity.Chapter II. It was studied by SDS-PAGE, protein turbidity determination and determinationof protein solubility that the gelation reaction of mixed myofibril (MPI) and soy protein isolate(SPI) catalyzed by transglutaminase (TG) at the different temperatures. The results show thereare substantial amount of cross-linking among SPI subunits, MPI components, and their mixtureswith TG treatments. So, they can form some polymers which will make for elastic gel forming.Chapter III. Take the mixing ratio of the MPI and SPI, TG enzyme concentration, ionicstrength as factors, the research level of each factor was determined by single factor test.Through the three factors three level response surface analysis, optimal interaction parameters ofthe TG enzyme was determined: mixing ratio of the MPI and SPI is3:20; TG enzymeconcentration is0.46gTG/g蛋白质; ionic strength is0.05mol/L. This regression model canprovide basis for rational development and utilization of SPI and freshwater surimi products.