Effects of Different Producing Areas and Extraction Methods of Polyphenols from Phyllanthus emblica L.

In this paper, Phyllanthus emblica from Guangdong, Guangxi, Fujian, Yunnan and Hainan were selected, and the content of polyphenols and antioxidant activities were compared and analyzed by subcritical water extraction, microwave-hot water extraction, solvent extraction, microwave extraction and ultrasonic extraction. The results showed that the content of polyphenol from Yunnan was the highest (345.24 mg GAE/g), while that from Guangdong was the lowest (198.83 mg GAE/g). Polyphenols were extracted by different extraction methods using Phyllanthus emblica from Yunnan. Subcritical water extraction showed the highest polyphenol content (387.33 mg GAE/g), while microwave extraction showed the lowest polyphenol content (223.45 mg GAE/g). Studies on antioxidant activity showed that the scavenging capacities of polyphenols for the hydroxyl radical from Yunnan was higher than those from other regions (P<0.05), which was 85.99%. There was no significant difference in ABTS⁺ -scavenging capacity of polyphenols from different regions, and the scavenging rate of all samples was above 97%. The DPPH-scavenging capacity of polyphenols from Yunnan was the lowest (70.01%). Among the different extraction methods, the DPPH·, ABTS⁺· and ·OH scavenging rates of polyphenols extracted by subcritical water were higher than those of other methods, and there was a significant quantitative-efficacy relationship between polyphenol concentration and free radical scavenging rate. Therefore, the subcritical water extraction would be a better choice to improve the yield and antioxidant activity of emblica polyphenols using Phyllanthus emblica from Yunnan.