【作者】 贾振宝；

【导师】 霍贵成；

【作者基本信息】 东北农业大学 ， 食品科学， 2002， 硕士

【摘要】 大豆在我国种植面积广泛，蛋白质含量高，是畜禽生产中最重要的蛋白质来源。但是大豆中含有的抗原蛋白会在幼畜体内引起过敏反应导致腹泻甚至死亡。目前生产中常用的蒸汽加热处理并不能有效失活大豆中的抗原蛋白。本课题针对这一问题，采用凝胶过滤的方法从大豆中分离纯化一种重要的抗原蛋白—β—伴球蛋白，建立定量检测β-伴球蛋白的方法，并对利用蛋白酶失活大豆中β-伴球蛋白进行分析研究。 采用70％～90％分级盐析和琼脂糖凝胶Sepharose 6B(80×2.5cm)纯化大豆中的β-伴球蛋白，具有较好的分离效果。免疫电泳的结果证实所提取的β-伴球蛋白纯度较高，大豆中的其它成分与β-伴球蛋白抗血清无交叉免疫反应。SDS—PAGE的结果表明本实验所提取的β-伴球蛋白是由不同形式单体组成的复合物，共有六种亚基组成，分子量分别为72746Da、67747Da、63998Da、60249Da、57750Da、52751Da和68000Da。 利用β-伴球蛋白的抗血清，通过免疫火箭电泳，建立了定量检测β-伴球蛋白的方法，回归模型： H=0.0681C+0.4571 R~2=0.994 H—沉淀峰高度(mm) C—β-伴球蛋白浓度(μg/mL) 分别用Alcalase、Nutrase、AS1.398和木瓜蛋白酶水解豆粕至水解度为5％，豆粕中β-伴球蛋白的含量分别为57.6mg/g、58.2mg/g、58.0mg/g和56.4mg/g，结果表明上述四种蛋白酶在水解β-伴球蛋白的特异性上无明显差别。 以Alcalase作为水解用酶，比较不同水解度下豆粕中β-伴球蛋白的残留量，实验结果表明水解度小于10％时，水解对豆粕中β-伴球蛋白的含量影响较小，当水解度达到25％时，可使豆粕中的β-伴球蛋白完全消失。水解并不能提高豆粕中β-伴球蛋白对胃蛋白酶的敏感性。 综上所述，酶解可有效失活大豆中的抗原蛋白，这为生产低过敏大豆制品提供了新的方法和手段。更多还原

【Abstract】 Soybean is widespread in our country, and is rich in protein. It is the major protein source for livestock production. But the allergic proteins in soybean could cause immune hypersensitivity. and result in diarrhoea and mortality of animals. The protein with strong allergenic activity is resistant to heating and other processing .The purification of p-conglycinin which is the most critical dietary antigen in soybean is studied in this subject. Then it is studied to destroy allergic protein by hydrolysis with proteases.p-conglycinin in soybean is purified by salt precipitate on 70%~90% saturation and gel filtration on a Sepharise 6B column(80 X 2.5cm). The result of immunoelectrophoresis illustrated the purified p-conglycinin is not contaminated by the other proteins in soybean. The purified p-conglycinin is heterogeneous, and is composed of six kinds of subunits. Based on SDS-PAGE the molecular weights of subnits were estimated at 72746Da, 6774 7Da, 63998Da, 60249Da; 57750 Da,52751Da and 48000Da respectively.The method to determine the quantity of p-conglycinin in soybean was made by rocket immuno-electrophoresis. The model was established:H=0.0681C+0.4571 R2-0.994H-height of ’rocket’ (mm) C-concentration of P-conglycinin (ug/mL)Soybean meal was hydrolyzed by Alcalase, Nutrase, AS1 398 and Papain respectively. When the degree of hydrolysis reach 5% the concentration of p-conglycinin is 57.6 mg/g,58 mg/g .58.2 mg/g and 56.4 mg/g. The result shows there is few difference in the speciality to hydrolyze the allergic protein among these enzymes.The concentration of p-conglycinin in soybean meal was compared after different degree of hydrolysis. There is little effect on the quantity of p-conglycinin when the DH is below 10%. The p-conglycinin in soybean meal was inactivatesd wholly when the DH reach 25%. Hydrolysis could not improve the susceptibility of p-conglycinin to pepsin.To sum up, allergic protein is destroyed after sufficient hydrolysis by protease. This contributes a new method to make hypoallergenic soybean products.更多还原