摘要
为研究乳清中β-乳球蛋白环保、温和、高效的分离工艺,该文对采用蛋白酶选择性水解然后超滤分离乳清水解液中的β-乳球蛋白进行研究。试验对乳清水解物进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)分析,比较了胃蛋白酶、胰蛋白酶、木瓜蛋白酶和中性蛋白酶的选择性,并分别采用分子截留量10000的聚砜膜(PS-10)和聚醚膜(PES-10)对胃蛋白酶解液进行超滤处理。结果显示,β-乳球蛋白对胃蛋白酶耐受性较好,α-乳白蛋白对木瓜蛋白酶抗性较佳,但二者均对中性蛋白酶较敏感。较优的水解分离条件如下:乳清蛋白质量浓度8%,胃蛋白酶添加量为乳蛋白质量的0.3%,pH值2.1,温度37℃,水解2 h,α-乳白蛋白近似完全水解而β-乳球蛋白几乎不被降解。水解液用PS-10膜超滤分离,β-乳球蛋白的纯度和产率达到了较高,分别为94.6%,75.6%。因此,采用选择性酶解处理乳清然后超滤分离β-乳球蛋白是可行的。
To isolate β-lactoglobulin（β-Lg） environmental friendly, high efficiently and under mild conditions from whey, a novel method including selective protease treatment of whey and ultrafiltration of hydrolysates was investigated. Whey hydrolysates hydrolyzed by pepsin, trypsin, papain, and neutrase were analyzed respectively in terms of selectivity of proteases by SDS-Polyacrylamide Gel Electrophoresis（SDS-PAGE）. The ultrafiltration （UF） was performed using polysulfone membrane PS-10 or polyether sulfone membrane PES-10 with 10000 molecular weight cut-off limit, respectively. The SDS-PAGE indicates that β-Lg is resistant to pepsin digestion, while α-Lactoalbumin （α-La） is not sensitive to papain. But both proteins are susceptible to neutrase. When 8% whey protein solution was hydrolyzed by 0.3%（rn/m） pepsin at 37 ℃, with pH value of 2.1, for 2 h, all the α-La was digested and little β-Lg was degraded. The 94.6% purity and 75.6% yield ofβ-Lg could be reached, when ultra-filtration was performed with PS-10 membrane at 40℃, under 0.22 MPa and with pH value of 6.0. Hence, proteolysis of whey coupled with ultrafiltration treatment is feasible to separate β-Lg.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2008年第5期280-283,共4页
Transactions of the Chinese Society of Agricultural Engineering
基金
浙江省自然基金资助项目(Y305058)
浙江省教育厅资助项目(20050251)
