Study On Extraction, Purification And Antioxidation Of Flaxseed Lignans

Flaxseed is an important source of lignan which is a kind of phytoestrogens. Because of its antioxidation, antitumor, anticardiovascular and cerebrovascular diseases, relieve menopausal symptoms and other biological characteristics, flaxseed lignans have a broad market prospect in the food, pharmaceutical, health products and cosmetics industry. This paper compared the yield of flaxseed lignans with ultrasonic and supercritical CO2extraction, and purified with X-5macroporous adsorption resin. Then taking the inhibitory of superoxide anion as the standard, antioxidation of flaxseed lignans and Vc is analyzed and compared. The main results were as follows:(1)By single factor experiment and response surface optimization experiment to study the process conditions of flaxseed lignans with ultrasonic extraction. The results of the optimum extracting conditions were shown as follows:ultrasonic power320W, the ethanol concentration of72%, ultrasonic time21min, and the lignans yield was2.21%.(2)By single factor experiment and response surface optimization experiment to study the process conditions of flaxseed lignans with supercritical CO2extraction. The results of the optimum extracting conditions were shown as follows:extraction temperature40℃, extraction pressure26MPa, extraction time125min, and the lignans average yield was2.59%.(3)Selecting X-5macroporous resin to separate and purify flaxseed lignans, the optimum purification conditions were as follows:10mg/mL of flaxseed lignans were adsorbed on the speed of0.3mL/min, and eluted with5column volumes of20%ethanol solution at the flow rate of1ml/min. After purified by column chromatography purification, purity of flaxseed lignans can reach73.6%(4)Using pyrogallol autoxidation method for determining the antioxidant activity of flaxseed lignans. Compared with the same concentration of VC solution, inhibitory of superoxide anion of flaxseed lignans were better than Vc.Until the end of the reaction,the inhibition rate of Vc on pyrogallol autoxidation quickly dropped to10%or less, but the inhibition rate of flaxseed lignans on pyrogallol autoxidation remained at20%or more.Relatively speaking, the antioxidant activity of the flaxseed lignan was more efficient and durable than Vc.