The Development Of Sesame Protein And Peptide

The defatted sesame cake was used as the raw material. The extraction, purificationprocess of sesame protein and preparation of sesame peptides was studied. On the basis ofthis further study was conducted on the influence of different degree of hydrolysis ofsesame polypeptide features, in order to provide the theory basis for processing andcomprehensive utilization of sesame protein and polypeptide. The principal contents are asfollows：1. The alkali extraction and acid precipitation process conditions of preparation ofsesame protein were studied. The optimum parameters are as follows: extractiontemperature55℃, pH value10.5, extraction time2.5h, solid-liquid ratio1:12. Verificationtest was performed under this condition, the protein extraction yield was68.21%.2. The optimum conditions of ultrasonic assisted extraction of alkali extraction andacid precipitation of sesame protein was: extraction temperature50°C, pH10.0, extractiontime120min, solid-liquid ratio1︰10, ultrasonic power180w. Verification test wasperformed under this condition, the protein extraction yield was82.36%. Conpared withthe pure alkali extraction and acid precipitation of68.21%, the protein extraction yield ofultrasonic assisted extraction imcreased by14.15%.3. The optimum conditions of the sesame protein purification of using glucoamylaseenzyme was: enzymolysis temperature60°C, enzymolysis pH values4.0, enzymolysis time30min, glucoamylase dosage80U/g, solid-liquid ratio1︰10. Verification test wasperformed under this condition, the protein purity was82.85%, the protein extraction yieldwas78.52%. On this basis, the influence of glucoamylase treatment for many times onsesame protein purity and the extraction rate was studied, the results indicated that: the bestglucoamylase enzymatic hydrolysis was two times, then the sesame protein content was86.10%, the extraction yield was72.26%.4. Four kinds of more effective protease was selected to prepare sesame polypeptide.After determination of protease activity and hydrolysis experiments, the results indicatedthat: enzymolysis effect of alkaline protease was the best. The optimum technological conditions of preparation of sesame peptide by alkaline protease enzymolysis was:enzymolysis temperature50℃, enzymolysis pH10.0, enzymolysis time4h, enzyme dosage4500u/g, substrate concentration3%. three parallel verification experiment was performedunder this condition, the average degree of hydrolysis was20.30%.5. The sesame protein was used as the raw material to study the changes of differenthydrolysis degree of sesame peptide functional properties. The results indicated that: Withthe increase of hydrolysis degree, the solubility, water holding capacity, oil holdingcapacity, emulsification capacity, foaming capacity and viscosity of sesame polypeptidehad a certain degree of increase, but the emulsion stability decreased, foaming stabilityincreased under acidic conditions, decreased under basic conditions. Wherein the solubilityand foaming capacity were the minimum at the isoelectric point (pH4) and higher underthe conditions of departing from the isoelectric point; Water holding capacity and oilholding capacity reached the maximum at40℃, decreased under the conditions of deviate40℃; with increasing pH emulsification capacity continued to rise; emulsion stabilityreached the maximum at pH4, decreased deviating from the condition; foam stabilitydecreased gradually, had a small increase at pH2and5; Within the scope of the pH1~11,viscosity increased when pH less than7and decreased when pH more than7.