Study On The Purification Process Of Tea Polyphenols And Separation Process Of Catechins

The polyenols in tea have important functions in health care for human being, and much more attention has been paid to it increasingly. The functions of catechins in tea polyphenols is relevant to many situations of practical interest. Typical examples include anticancer, antioxidant, antisenescent, antiaberrance, antihypertensive, hypoglycaemic, radiation protection. As tea polyphenols are being the material of healthy food and natural cosmetic, there are general applications on the industrial fields such as medicine, chemical product, food and grease. How to acquire pure tea polyphenols and catechins safely and effectively is the aim of scientists.TP50 and TP80 being the raw material, a safe and effective process which can purify the tea polyphenols and a relevant analytical method are found based on salt out, filtration and HPLC. The results indicate that the process of salt out can reduce the impurity in tea polyphenols effectively. The content of tea polyphenols rises with increased concentration of salt at low saline concentration (<5%), moreover the content lessens when the concentration of salt is larger than 5%. The content of esterified catechins increases at 4°C after salt out. The purities of tea polyphenols can rise to 54.2% from 50.8% and to 85.1% from 81.4% after the process of salt out.The contents of tea polyphenols and catechins lesson with decreased the diameter of micro-filtration or the molecular weight cut-off after the process of filtration. The purities of tea polyphenols can rise to 56.2%, 65.1% and 73.1% (TP50) and to 86.5%, 89.1% and 93.2% with the molecular weight cut-off of 100 000, 50 000, 10 000, which means the purity of tea polyphenols could increase remarkably by way of filtration.Three kinds of catechins (C, ECG, EGCG) have been separated by HPLC, whose purities are larger than 99.5% and ratios of outcome are larger than 75%.