Study On The Enzymic Hydrolysis Of Protein Of Silver Carp By-product

The ratio of meat of Silver carp was less than 40%, made the product of Silver carp highcost and low profit. In this thesis,firstly, we utilized the by-product of Silver carp such as fishhead. fish skin and fish bone and researched the proteolysis peptide of by-product that werehydrolyzed.The sample was defatted by extraction. This made DH. NR and TCA-NSI were better thanhydrolysates that before degrease.We adopted the regression model of three factors five levels two time rotaion pependicularregressive design.By F-inspection and Tinspecion and applied inspection, the model wasverified tha it reflected theoretically the intrinsic law on protein hydrolysis of by-product ofSilver carp, and coincided well with the practice. It could reflect the intrinsic relationship ofhydrolysis process and protein yield really With the design of rotaion regression, we verifiedtha three factors namely [E]/[S], pH-value and temperature were the main factors whichaffected the fact tha Alcalase hydrolyzed the protein of Silver carp by-product. Thecontribution of thee factors to protein yield was temperature > pH-value > [E]/[S]. Theoptimum hydrolysis condition of hydrolyzing the protein of Silver carp by-product byAlcalase was: [E]/[S]=3.33%,pH=8.54, T=58℃,time=90min.We also determined the distribution of the molecule weigh of peptide of hydrolysate bydifferent DH (degree of hydrolysis). With the increasing of DH, average MW (moleculeweight) of peptide of hydrolysate decreased, and the unhydrolyzed proteins or big peptidemolecules and amino acids were in the minority and the number of small peptide moleculesincreased.Composition of amino acid indicated tha by-produc was deficient in isoleuine,hydrolysates and meat were deficien in methionine and cysteine.Hydrolysates had excellent solubility Which better than the originals; Had fine heat stabilityand chill stability;Wiscosity was not affected by temperature;The bubble volume was 3.4~4.3times as that of initial's;The foam stability was decreased at acid condition;Hydrolysateswere no bitter and no fish flavor.Anti-fatigued test of little mouse suggested the following: After the little mouse drunk theprotein hydrlysate of by-product of Silver carp, the content of bloody lactic acid aftersporting decreased remarkably the content of bloody urea nitrogen decreased, time ofswimming test of the little mouse with weigh increased remarkaly, thus the resultS aboveilluStrate that the protein hydrlysate had the nOallle ani-fa tiped function.The optndum recipe of PePtide drink was the following: cOntent of acid 0.04%,content ofsugar 8%, fl -cyclodextrin 0.6%.POstgraduate: Zhao YuhngSpeciaIity: Food ScienceSuPendor: vice-pro f Kong Baohua...