Chemical modification and antioxidative activity of liposoluable tea polyphenols

Liposoluable tea polyphenols(LTP) were synthesized by chemically modifying tea polyphenols(TP) with stearyl chloride. FTIR analysis indicated that carbonyl and long carbon chain were introduced into the tea polyphenols. The optimal process parameters were given as follows: n(TP)/n(stearyl chloride)/n(Na 2CO3) = 1/1.5/1.5, and the experimental conditions were controlled at 80°C for 4 h. The applications of TP, LTP and other antioxidants added to the walnut oil were investigated. The results show that the composition of LTP and natural vitamin E is best antioxidant, and LTP is more effective than TP. © 2011 IEEE.