山羊乳酪蛋白酶解工艺研究

Study on enzymolysis technology of goat's milk casein

【目的】确定山羊乳酪蛋白的酶解工艺,为制备山羊乳酪蛋白活性肽奠定基础。【方法】选用中性蛋白酶、胰蛋白酶、木瓜蛋白酶和碱性蛋白酶,采用对比和正交试验方法,研究山羊乳酪蛋白单酶和复合酶的酶解工艺,测定山羊乳酪蛋白的总肽键物质的量,优选山羊乳酪蛋白的酶解工艺参数。【结果】山羊乳酪蛋白的总肽键物质的量为8.5379mmol/g。单酶中,胰蛋白酶和中性蛋白酶对山羊乳酪蛋白的水解度均较大,木瓜蛋白酶次之,碱性蛋白酶最小;胰蛋白酶对山羊乳酪蛋白的水解度最高,为14.67%,其适宜的酶解工艺为:加酶量2500U/g,pH7.5,50℃下酶解2h。复合蛋白酶中,中性蛋白酶和胰蛋白酶复合及中性蛋白酶、胰蛋白酶和木瓜蛋白酶3酶复合时的水解度均较大,2种复合酶的水解度、平均肽链长度和平均相对分子量分别为17.34%,21.16%;5.77,4.73和692,567。【结论】在最佳酶解工艺条件下,单酶中,胰蛋白酶和中性蛋白酶对山羊乳酪蛋白水解度均较大,复合酶中,中性蛋白酶、胰蛋白酶复合及中性蛋白酶、胰蛋白酶和木瓜蛋白酶3酶复合时的水解度均较大。

[Objective] Enzymolysis technology of goals milk casein（GMC） was studied in order to provide a theoretical foundation for the preparation of peptides derived from GMC. [Method] GMC was hydrolyzed with its single and complex enzyme,single enzyme including neutral protease（N）, trypsin（T）,papain（P） and alkaline protease（A） ,and the content of amino nitrogen and total peptide bond amount of substance and degree of hydrolysis of GMC were determined to optimize enzymolysis technology parameter for GMC. [Result] The total peptide bond amount of substance of GMC was 8. 537 9 mmol/g. The degree of hydrolysis of trypsin and neutral protease for GMC was higher than that of papain,and that of alkaline protease was the lowest among single enzymes. The optimum enzymolysis technology of trypsin for GMC was hydrolyzed for two hours at 50 ℃, enzyme dosage 2 500 U/g and pH 7.5. The degree of hydrolysis of complex enzyme consisting of neutral protease,trypsin and papain was higher than that of the complex enzyme consisting of neutral protease and trypsin among complex enzyme. And its degree of hydrolysis, average peptide chain length and their average relative molecular mass was 17.34% ,21.16% %;5.77,4.73 and 692, 567 respectively. [Conclusion] Under optimum enzymolysis conditions,the degree of hydrolysis of trypsin and neutral protease for GMC was higher than other protease among single enzymes, and the complex enzymes consisting of neutral protease, trypsin and papain, and consisting of neutral protease and trypsin were higher than that of other complex enzyme.