Separation, purification and antioxidant activity of polyphenols from brown alga Kjellmaniella crassifolia Miyabe
WANG Shuai, ZHI Lichao, LIANG Xinyuan, WU Zhe, ZHANG Mengyu, REN Dandan*, HE Yunhai, WANG Qiukuan
College of Food Science and Engineering,Key Laboratory of Aquatic Product Processing and Utilization of Liaoning Province,Nation Research and Development Branch Center For Seaweed Processing, Dalian Ocean University,Dalian 116023, China
Abstract: Polyphenols were separated and purified from brown alga Kjellmaniellacrassifolia Miyabe by macroporous resins and the optimal separation conditions were investigated by static adsorption desorption test and dynamic elution test. The antioxidant activities of polyphenols were determined by various methods including DPPH radical and hydroxyl radical scavenging system, ferric ion reducing antioxidant power and oxygen radical absorbance capacity. The results showed that macroporous resin XDA-1 was the optimal resin for separation, and that the best separation of polyphenols from the brown alga was observed under the optimum conditions of 15 mg/mL of sample concentration, 100 mL of sample volume, 1 mL/min of rate, 70% ethanol of eluent, and 200 mL(2 BV) of elution volume. After elution, two separated components P1 and P2 were obtained, with polyphenol content of 15.7 times of the crude polyphenol in P1, and 3.7 times of the crude polyphenol in P2. The antioxidative tests indicated that all the polyphenols from the brown alga had strong antioxidant activity, P2 showing higher antioxidant activity than other samples (P<0.05) by measuring·OH scavenging ability, FRAP value and ORAC value. There was significant IC50 of scavenging DPPH radicals in P1 compared with other samples (P<0.05), indicating that P1 also had a good antioxidant activity. In conclusion,polyphenols from Kjellmaniellacrassifolia Miyabe purified by XDA-1 resin had strong antioxidant activity and were a good source of natural antioxidants.