STUDY ON OPTIMIZING EXTRACTION TECHNOLOGY OF TOTAL FLAVONOIDS FROM CAULIFLOWER USING RESPONSE SURFACE METHOD

Flavonoids are polyphenolic substances isolated from a wide range of plants which exhibit biological activities,including antiallergenic,antiviral,anti-inflammatory,and antioxidant activities.It has been accepted that cauliflower had higher content of total phenolic compounds.In this study,the extraction process of total flavonoids from cauliflower (Brassica oleracea L.var.botrytis L.) was optimized in order to provide technical references for development and utilization.Here,flavonoid compounds were extracted from cauliflower by organic solvent refluxing,and response surface analysis methodology (RSM) was employed to optimize the extraction process of total flavonoids.The factors affecting extraction efficiencies including extraction temperature,extraction time,ratio of raw material and organic solvent and ethanol concentration were evaluated using Box-Behnken experimental design.The primary and secondary order of four factors affecting yield of total flavonoids were as follows:raw material-organic solvent ratio equal to extraction time,extraction temperature,and ethanol concentration.The optimal conditions for total flavonoids extraction were listed as follows:temperature 80℃,extraction time 2.2 h,ethanol concentration 80%,raw material-organic solvent ratio 1:35.The predicted extraction yield of total flavonoids was 2.922 mg/g,and the verification was 2.935 mg/g indicating that the combination of Box-Behnken design and response surface analysis could well optimized the extraction technology of total flavonoids from cauliflower.