Optimization of Flavonoid Extraction from Ganoderma lucidum by Response Surface Methodology and Antioxidant Activities of Extracts

Enzyme addition in the hot water extraction of flavonoids from Ganoderma lucidum was investigated for improvements on the extraction efficiency and/or enhancement on the antioxidant activity of the extract. The single factor test and the response surface methodology were used to optimize the processing conditions. It was found that a maximized yield of flavonoids of 0.75 mg/g could be obtained with the use of a combination of cellulase, pectinase and neutral proteinase in the ratio of 2.07:0.86:2.11 for the extraction at pH 5.0 and 50^oC for 80 min. The resulting extract exhibited a high reducing power as well as free radical scavenging activities on DPPH and hydroxyl free radicals.