The Study On Desalination Technology And Functional Properties Of Silver Carp Protein Hydrolysates

Silver carp is the fish species of biggest production in china,which is rich in good protein,however,its processing accounts for 5%.Now,the processing technique for Silver carp is to mix a certain proportion of the Silver carp fish and organs,which enzymolyze the protein to the peptide of small molecule by enzyme of internal source in Silver carp. This reaction needs constant alkalinous enviroment,and acid are added to demulsifiy after enzymolysis,which make the salinity of protein powder to 25.97%.this paper is to obtain ion-exchange resins for desalination of Silver carp proteolysis liquid by static selection with protein powder as material,base on this the process for desalination of Silver carp proteolysis are optimized and nutritive peculiarity,physicochemical property and functional property of protein powder before and after desalination are compared and analyzed.The main research results are:1.The selection for anion and cation exchange resin. Eight resin are choosed for experiment including 001×7,001×16,D113,D151, 201×4,201×7,D201,D301 and measuring the basic functional index including exchanging capacity and water content. the best cationic and anion resin are 001×16 and 201×7 for silver carp protein hydrolysates by static selection with retention rate of protein and desalting rate as index.2.The study on the effect of desalination process index on silver carp protein hydrolysates desalination. The effect of flow rate, raw material concentration,ambient temperature,column order and column size on desalination are studied using the rate of protein retention and desalination as an indicator.The result show that the optimum technology is:the flow rate is nine times the column volume/h,the raw material concentration is 20%,the ambient temperature is 15℃,the volume ratio of Ion-exchange resin is 2:1,and the effect for going through anion resin first and then the cationic resin is better,at that time,the retention rate of protein is 91.35%,the sodium removal rate is 87.54% and the dechlorination rate is 85.67%.3.Study on the change of basic composition of silver carp protein hydrolysates before and after desalination.before desalination, the moisture, protein, fat, ash, chloride ion, sodium ion are 4.58%,49.89%,10.72%,28.78%,15.87%,10.1%. after desalination, rate are 6.61%,77.33%,6.37%,6.80%,2.38%,1.42% respectively, and salinity are down by 8.68%, protein up by 27.44%.4.The of protein peptide molecular weight distribution and functional property of silver carp protein hydrolysates including water holding capacity, oil absorption, emulsifying capacity,emulsion stability,foaming, bubble stability and viscosity are compared before and after desalination. The protein molecular weight is 80-3500Da before desalination and 80-2000 Da after. The silver carp protein hydrolysates have good water holding capacity, oil absorption, emulsifying capacity, emulsion stability,foaming, bubble stability and viscosity, and the functional property of carp protein powder have little change after the desalination.