【作者】 杨勇；

【导师】 杨贤强； 赵正惠；

【作者基本信息】 浙江大学 ， 茶学， 2004， 硕士

【摘要】 系统研究了从茶多酚工业废液(以下简称废液)中提取纯化茶氨酸的方法。茶多酚工业废液中含有大量的茶多酚、糖类及蛋白质等杂质，研究采用各种分离的手段，如絮凝、超滤、吸附、阳离子交换及重结晶的工艺来除去杂质，分离纯化茶氨酸。并对各分离工艺进行优化，得到最佳工艺参数。结果表明： 絮凝能有效去除工业废液中的多糖类与蛋白质等杂质。经絮凝后，茶多酚废液溶液由混浊变为澄清，O.D.650值由1.5降至0.2左右，蛋白质杂质减少了50％，可溶性糖的含量也降低20％，茶多酚含量变化不大，茶氨酸的回收率超过95％。最佳絮凝工艺条件为壳聚糖添加至浓度4mg／mL，溶液pH为3.0～4.0，温度为20-30℃。 超滤能进一步澄清溶液，降低溶液中蛋白质等大分子物质的含量。研究结果表明，超滤的最佳工艺为选择十万分子量的醋酸纤维素膜，处理液温度为35-45℃时，以0.1-0.15MPa的工作压力进行操作，可得到较好的处理效果。通过超滤，蛋白质含量减少48％，可溶性糖含量下降25％，茶氨酸有一定程度的被截留，茶氨酸回收率约为90％。 吸附能进一步去除色素、多酚类物质及大分子有机物。筛选出一种对杂质吸附较多，同时茶氨酸的回收率较高的树脂—AB-8。静态吸附实验表明在35℃、溶液pH在4.0左右时，AB-8树脂对多酚类等有机质的吸附量最大。通过动态吸附法考察了树脂在不同流速、不同上样浓度及不同树脂层高径比条件下茶多酚的穿透曲线。结果表明，采用1.0BV／h的流速，树脂层高径比在10：1左右时进行动态吸附，单位树脂的吸附量最大。70％的乙醇的解吸性能较好。 阳离子交换树脂能较专一吸附氨基酸，不同阳离子交换树脂在吸附氨基酸的选择性上相差不大。离子交换树脂以732树脂为宜。在上样液茶氨酸浓度为1.5mg／mL时，溶液pH在3.0左右时，控制流速1.0BV／h，单位体积树脂吸附容量较大。洗脱液选择1.5mol／L的氨水，控制流速为1.0 BV／h，收集1.5倍柱体积沈脱液。洗脱液60℃减压浓缩挥去氨后，溶液冷冻干燥得粗茶氨酸。 乙醇重结晶法可得到较高纯度的茶氨酸。10％(W／V)粗茶氨酸液加入4倍体积乙醇，在常温下振荡混匀静置1h后，离心分离去除产生的沉淀。离心清液60℃减压浓缩为80％(W／V)的溶液，冷却后加4倍体积冷乙醇，0℃下冷藏24h，可产生结晶状物质，4℃、8000rpm／min离心得类白色固体，经检测此固体物茶氨酸纯度为65％。将所得固体用少量热水溶解，同上述方法重结晶3次。所得晶体60℃下真空干燥，可得纯度＞90％的茶氨酸产品。不吹士学位论文 通过以上絮凝*超滤、吸附*阳离子交换*重结晶的工艺，可得到纯度超过%%的茶氨酸产品，茶氨酸回收率为35%，产品得率为0.8%。更多还原

【Abstract】 Techniques of isolation and purification of theanine from tea polyphenol waste industrial liquid were studied in this paper. To get rid of tea polyphenol, protein, soluble sugar in waste industrial liquid, some of chemical technique for separation, such as flocculation, membrane ultra filtration, absorption, ion-exchange absorption and re-crystallization were employed. To optimize the techniques,conditions of techniques were studied . The result suggested that:Focculation can efficiently remove protein. Effects of concentration of chitson, pH and temperature of solution were investigated. After flocculation, the solution become clear, the O.D.650 value decrease from 1.5 to 0.2, 50% protein and about 20% soluble sugar were removed, the content of tea polyphenol remain unchanged under the optimum conditions while the recovery rate of theanine was 95%. The optimum conditions were the mass concentration of chitson was 4mg/mL, pH was 3.0- 4.0, temperature was 20-30℃.Memberane ultrafiltration can efficiently remove protein and polyphenol. Effect of different pore diameter, temperature of solution and work pressure were studied. The result showed that ultrafiltration can clarify the solution. 100k CA membrane may be suitable, 25-35℃ and 0.1-0.15Mpa work condition may be the fittest. Under the optimum conditions, the removal rate of protein was 48% and soluble sugar was 25%, the recovery rate of theanine was 90%.4 kinds of adsorbents were used to study adsorption performance for TP. The result showed that AB-8 is a kind of good adsorption for TP. The pH, temperature of solution that affect adsorption performance were studied. The adsorptive capacities of AB-8 resin were the most, while elute speed was 1.0 BV/h and the ratio of height to diameter of column was 10:1. 70% ethanol was the efficient eluant.The purification method of crude theanine was studied with ion exchange resin. Amino acid was primary purified from the extact of tea with cation resin. The optimal cation resin operation conditions were pH 3.0, 1.5mg/mL theanine solution, the elution rate 1.0BV/h. The saturated cation-exchange resin was eluted with different concentration solution of NH3.H2O. In view of the result, no matter what eluent concentrations of NH3H2O( from 1.5mol/L to 0.2mol/L) were adopted , the purity of theanine had no difference. Under the optimal condition, the rate of recovery oftheanine was 87% and purity of the product was 50%.A crystallization method had been examined to obtain theanine with high purity. In this process, the crude theanine obtained by cation resin technique was dissolved in the 80% ethanol, and then theanine was crystallized from ethanol solution at 0℃ for 24 h. The rate of recovery of theanine was 70% and purity of theanine crystals was 65%. Through re-crystallization we can get theanine which purity was 90%.Through this technique, the final yield and purity of the product were 0.8% and 90%.更多还原