Abstract: The effects of the extraction parameters on the yield of flavonoids from Citrus peels were studied, the process parameters were optimized by L9(34) orthogonal tests based on single factor tests with the yield of total flavonoids as index. The results showed that the order of the extraction parameters affecting the yield of flavonoids is as follows: dosage of cosolvent> pressure>temperature>time. The optimal process parameters are 55 ℃, 200 BAR (1 BAR=0.1 MPa), 150 min and 0.35 ml/ min. The maximum extraction yield is 2.723%.

Key words: supercritical carbon dioxide extraction, citrus peels, total flavonoids