3LM-12 : Optimization of the extraction of phenolics and flavonoids from the fruit of Empetrum nigrum var. japonicum from Jeju Island in South Korea using response surface methodology(RSM)

Empetrum nigrum var. japonicum (crowberry), an endemic species in South Korea, can be used in both food and medicine. A fourfactor- three-level Box-Behnken design (BBD) was employed to predict the optimized conditions with extraction time of 42.75 min, extraction temperature of 52.48°C, liquid-solid ratio of 288.76:1 and concentration of ethanol of 71.74% for total flavonoid content while 114.75 min, 58.41°C, 670.26:1 and 61.67% ethanol for total phenolic content. A total amount of 74.778 mg/g and 73.882 mg/g of phenolic and flavonoid were extracted under the optimized conditions, which agreed with the predicted response from the model. The extraction methods were applied successfully to extract total phenolic and flavonoid from Empetrum nigrum var. japonicum. Moreover, the antioxidant experiment results showed that the maximum DPPH radical scavenging ability reached 91.48% when extracts contained 0.11μg per gram of dry crowberry.