摘要：茶籽粕是茶籽提取茶油后的副产品，含有茶皂素、多糖、蛋白等多种活性成分。本实验利用茶籽粕作为原料，以碱法提取法提取其中的茶籽蛋白，并对获得的茶籽蛋白的体外抗氧化活性进行了研究。茶籽蛋白的提取实验中在单因素实验基础上进行响应面实验，选择碱液浓度、提取温度、提取时间、料液比4个因素，每个因素设置了4个水平，最终获得了茶籽蛋白最佳提取工艺为：碱液浓度0.013mol/L,提取温度39.5℃，提取时间61.22min，料液比1:40.32。在最佳提取条件下，碱法提取的茶籽蛋白得率为10.08%。 茶籽蛋白体外抗氧化主要研究了对DPPH自由基的清除作用，结果表明，当蛋白浓度分别为0.5mg/mL、1 mg/mL、2 mg/mL、4 mg/mL和8 mg/mL时，对DPPH自由基的清除率分别达到4.43%、9.88%、14.58%、23.85%和32.52%。39299
毕业论文关键词：茶籽粕；茶籽蛋白；提取；抗氧化活性；DPPH自由基；清除率
Extraction and antioxidant activity of tea seed protein
Abstract: Tea seed meal is the byproduct of tea oil production, which contains tea saponin, polysaccharide and protein with functional activities. In this study, we utilized tea seed meal as materials and extract protein using alkaline extraction method. In addition, we also investigated the antioxidant activity of protein obtained. Based on Single Factor design, response surface method was used to obtain optimal extraction conditions, selecting four factors including the concentration of alkaline, temperature, time and the solid-liquid ratio, and four levels for each factor. The optimal extraction conditions were as follows: the concentration of alkaline, 0.013mol/L, temperature, 39.5 oC, time, 61.22 min and the solid-liquid 1: 40.32. Under the optimal extraction condition, the yield of protein reached 10.08%. The antioxidant activity of tea seed protein has also been investigated through measuring the scavenging effects of DPPH free radical. The results indicated that the scavenging rates of DPPH free radical were 4.43%, 9.88%, 14.58%, 23.85% and 32.52% when the concentrations of protein were 0.5mg/mL, 1 mg/mL, 2 mg/mL, 4 mg/mL and 8 mg/mL.
Key words: Tea seed meal; tea seed protein; extraction; antioxidant activity; DPPH free radical; scavenging rate
目 录
1.引言 5
1.1本课题国内外研究现状概述 5
1.2蛋白质的提取方法 8
1.3本课题的研究目的和意义 9
2.材料与方法 11
2.1实验材料 11
2.2 实验试剂 11
2.3仪器与设备 11
2.4实验方法 11
2.4.1蛋白质含量的测定 11
2.4.2碱法提取茶籽蛋白 13
3.结果与讨论 16
3.1碱法提取茶籽蛋白单因素试验 16
3.1.1 提取温度对茶籽蛋白得率的影响 16
3.1.2 提取时间对茶籽蛋白得率的影响 16
3.1.3 料液比对茶籽蛋白得率的影响 17
3.1.4 碱液浓度对茶籽蛋白得率的影响 18
3.2茶籽蛋白提取的响应面实验 19
3.2.1二次响应面模型拟合 19
3.2.2各考察因素及相互作用对茶籽蛋白得率的影响 21
3.2.3 回归方程优化和最佳提取工艺的确定 24
3.3茶籽蛋白对DPPH自由基的清除作用 26
4.结论．．．．．．．．．．26
致 谢 28
参考文献 29
1 引言
1.1 本课题国内外研究现状概述
1.1.1 茶籽综合利用研究现状
中国是茶叶的故乡，茶叶的生产量和消费量都居世界之冠。目前我国茶叶种植面积接近200万公顷。茶籽为茶树所结的种籽，为茶叶生产中的副产品。目前在茶籽的综合利用研究上主要集中在从茶籽中提取茶籽油、茶皂素，淀粉和茶籽蛋白，以及茶籽粕的利用，茶籽壳的生物活性功能研究等方面。 茶籽蛋白的提取及体外抗氧化活性研究:http://www.youerw.com/shiping/lunwen_39588.html