Research On The Production Technology For Phosphopeptide And Its Functional Properties

This article was one part of the doctor fund topic-Study on the extraction of phosvitin and then preparation of phosvitin phosphopeptide through hydrolization that was charged by Professor Liu Jingbo in Agronomy Department of Jilin University. The powder of yolk was used as the material and the preparation technology of phosvtin was the main study object. Through twice enzymolysis, the crude phosvitin prepared according to a proper extracting condition was hydrolyzed, then the phosphopeptide that can contain more calcium was prepared. The results in different phases were list as follows:(1) The extraction technology of phosvitin was investigated initially, the N-hexane and Alcoholic was chosen as the extracting organic solvent. The non-water-soluble protein and the fat residual were the study target, and then the optimizing parameters in the processing of extraction were as follows: volume ratio of Alcoholic and N-hexane was 1:3, water volume was 120ml, total volume of organic solvent was 260mL.(2) Ammonium sulfate precipitation procedure was investigated, however, the ammonium sulfate can't separate the purpose protein andhybridportein enough, and as a result, it can't be used to separate phosvitin. The N/P (molar ratio) and Sodium dodecylsulphate (SDS)-polyacrylamide gel electrophoresis (PGE) were used to calculate the relative molecular mass or other targets, finally, the phosvitin with a high purity was obtained. The N/P was 4.32.(3) Four kinds of prolease (parenzyme, Alcalse, alkaline proteinase 2709 and dispase) were compared, and then the proper prolease used in the first step of enzymolysis. In the first step of enzymolysis, the optimizing parameters were established according to an investigation of single factors and orthogonal experiment, what is more, the interaction of temperature and pH that can affect the enzymolysis was investigated. The optimizing parameters in the first step of enzymolysis were as follows: temperature 50℃, pH 8.0, enzyme volume 1.5mL, hydrolyzing time 4h, the interaction of temperature and pH were not significant. The degree of hydrolysis according to the optimizing parameters was 12.68%.(4) Trypsinase, alkaline proteinase 2709 and dispase were analyzed respectively, and then the dispase was chosen as the best enzyme to conduct the second step of enzymolysis. According to an investigation of single factors and multiple linear regression orthogonal experiment, the processing parameters were optimized and the regression equation was as follow:The significance level was 0.01 and the equation was fitting. Through a statistical test to multiple linear regressions, the significant factors were pH, enzyme volume, hydrolyzing time and the interaction of pH and temperature. The order of factors that contribute to the second step of enzymolysis was: enzyme volume> hydrolyzing time> pH. The optimizing parameters were: temperature 50℃, pH 7.0, enzyme volume 2.0g, hydrolyzing time 2.5h. The degree of hydrolysis in the second step of enzymolysis was 19.15%.(5) The calucium ethoxide precipitation method was used to purified Phosvitin phosphopeptide, N/P (mole ratio) was used as measurement index, the quadratic regression orthogonal combination design was used as tools, the best purification technical parameters of Phosvitin Phosphopeptide were optimized. The regression equation was:The significance level was 0.05 and the equation was fitting through F test. The optimal process parameters of the calucium ethoxide precipitation method were: the concentration of ethanol was 75%, the rate of ethanol extraction volume and the former PPP quality was 15:1; the N/P (mole ratio) of verification test samples was 15.67. It was same as the result 14.69 of regression equation. That proved the validity of the regression equation.(6) Some indexes of difference Phosvitin Phosphopeptide products were determined, such as contents of ash, contents of water, contents of total calcium, N/P (mole ratio) and contents of Phosvitin phosphopeptide. After first the content of phosphopeptide was 2.12%, N/P (mole ratio) was 21.45; after Second enzymolysis the content of phosphopeptide was 3.335%, N/P(mole ratio) was 21.25; by the calucium ethoxide precipitation method the content of phosphopeptide was 5.25%, N/P(mole ratio) was 15.98.(7) Extraorgan research experiments were carried out on the functional nature of Phosvitin phosphopeptide. Study found that Phosvitin phosphopeptide has effect of inhibit calcium acid phosphate and ferrous iron in precipitation; the influence of food processing conditions on the functional nature of Phosvitin phosphopeptide from two aspects of temperature and citric acid, the temperature has little impact on the Phosvitin phosphopeptide in the food processing, the functional nature of Phosvitin phosphopeptide was not change when it was heated 100℃for 30 minutes; Phosvitin phosphopeptide with citric acid has a certain synergy.