Abstract: The technology of total flavonoids extracted from Ginkgo biloba leaves by enzymatic hydrolysis was studied. Based on single factor test, the effects of the concentration of enzyme, pH value, temperature and time of enzymatic hydrolysis on the extraction yield of total flavonoids from Ginkgo biloba leaves were stuied by response surface methodology (RSM). The results indicated that cellulase shows the better ability of enzymatic hydrolysis. The optimum conditions of enzymatic hydrolysis are: :100U/ml concentration, 116min time, 40℃ and 4.5 pH value. The highest yield of total flavonoids was 2.63%. Comparing with single extraction with alcohol, the total flavonoids yield increase by 30%.

Key words: Ginkgo biloba leaves, total flavonoids, enzymatic hydrolysis, extraction, response surface methodology