【作者】 刘志强；

【导师】 贺建华；

【作者基本信息】 湖南农业大学 ， 动物营养， 2003， 硕士

【摘要】 我国畜牧业发展的最大问题是蛋白质资源不足，为充分开发菜籽蛋白资源，本文进行了水相酶解法提取菜籽蛋白的研究，具体内容包括酶的筛选及处理参数研究、酶解后水浸提工艺研究、菜籽蛋白提取液超滤工艺研究。 在酶的筛选及处理参数研究中，选取纤维素酶、半纤维素酶、果胶酶、蛋白酶，以及复合酶Ⅰ(纤维素酶、蛋白酶、果胶酶按活力比5：3：2组成)、复合酶Ⅱ(纤维素酶、果胶酶按活力比3：1)进行水相酶解法提取菜籽蛋白与油脂的单因素实验，并以不加酶传统水剂法做对照，结果表明：复合酶作用明显，单独的纤维素酶、果胶酶、半纤维素酶作用不明显。以复合酶Ⅱ对菜籽进行处理，采用响应曲面分析(RSA)方法研究，得出较优工艺参数为固液比1：5、加酶量30U／g、酶处理时间100 min。 在酶解后水浸提工艺研究中，以采用较优工艺参数酶处理后的菜籽乳液为研究对象，研究酶解后水浸提条件对菜籽油与菜籽蛋白得率的影响，得出pH、温度对油脂与蛋白质得率影响较大；浸提时间影响不显著。采用响应曲面分析(RSA)方法进行优化实验，得出酶解后水浸提的最适条件为固液比1：6.5，pH 9.6，温度52℃，浸提时间取98min。 对菜籽蛋白提取液采用超滤分离，进行超滤工艺参数研究，结果表明超滤过程操作压力、温度、料液的pH、料液蛋白质浓度对超滤效果有较大影响。试验结果表明，控制操作压力0.20-0.30 MPa，温度50℃，料液pH 9-10左右，并在超滤过程中采用稀碱液及Alcalase蛋白酶间断循环清洗就能确保超滤在相对高的膜透过速率下运行。 在以上最佳工艺条件下采用水相酶解法提取菜籽中的油脂与蛋白质，以超滤技术分离菜籽蛋白，菜籽油得率可达92.7％，蛋白质得率达82.3％，产品中菜籽蛋白含量达90％以上，明显高于传统水剂法，产品中异硫氰酸酯、恶唑烷硫酮均未检出。但在降低酶的使用成本及该工艺产业化方面有待进一步研究。更多还原

【Abstract】 The key problem in stockbreeding of our country is short of protein resource. In order to fully explore the rapeseed protein resource, we carried out aqueous enzymatic extraction which included the study on selecting enzyme and its treatment parameter, aqueous extraction technology after zymohydrolysis, the research on aqueous enzymic hydrolysis for rapeseed protein after ultrafiltration..During the study on the selection of enzyme and treatment parameter, we selected cellulose, hemicellulose, pectinase, protease, complex-enzyme I (protease, cellulose, pectinase were mixed in line with their activity ratio of 5:3:2), and complex-enzyme II (cellulose, pectinase in line with their activity ratio of 3:1). we calculated the output rate of rapeseed oil and rapeseed protein and made a contrast between this method and the traditional aqueous extraction without enzyme. It proved that the function of complex-enzyme was obvious, single cellulose, hemicellulose and pectinase were not so effective. To treat the rapeseed with complex-enzyme II, RSA was adopted to study the effect of the enzyme reaction parameter to the output rate of rapeseed oil and rapeseed protein, the results showed that the proper technology parameter were supposed to be as follows: the ratio of solid and liquid was 1:5, the enzyme quantity was 30u/g, and the enzyme treating time was 100 min.During the studying on water-extraction technology after enzymatic extraction we studied the effect of water-extraction condition after enzymatic extraction on the output rate of rapeseed oil and rapeseed protein, adopting the rapeseed emulsion which was treated by optimized technology parameter . The result showed that pH and temperature had important effect on the output rate of fats and protein, but the extracting time had no obvious effect.The RSA being adopted to the optimization experiment, we got the most proper conditions of water-extraction after enzymatic extraction: the ratio of solid to liquid was 1:6.5, pH was 9.6, temperature was 52C, extraction time was 98 min.During the research on the ultrafiltration technique of the rapeseed protein extraction liquid, we used ultrafiltration to treat the rapeseed protein extraction liquid made by the aqueous enzymatic extraction and undertook the parameter research of the rapeseedprotein ultrafiltration. We found that the ultrafiltration could be operated at a comparatively high Jv with the operation pressure of 0.20-0.30 Mpa, temperature of 50C, the liquid pH of 9-10 and the discontinuous and circulatory cleaning of the rapeseed protein extraction liquid with weak lye and Alcalase during the ultrafileration process.Extracting the oil and fat and protein of the rapeseeds with aqueous enzymatic extraction under optimal conditions, separating the rapeseed protein from the liquid with ultrafiltration technique, the rapeseed oil extraction rate should be 92.7% and the protein extraction rate 82.3% and the content of rapeseed protein in the product exceeded 90%.It was easy to prove that this method was better than conditional aqueous extraction. At the same time, the content of ITC and the OZT could not be found . But how to reduce the using cost and how to make this technology on an industrial scale need further study.更多还原