Abstract
This article is dedicated to the isolation of lignin-containing fractions from the flaxseeds Linum usitatissimum L. The main component of these fractions is lignan-secoisolariciresinol diglucoside (SDG). The authors have developed an effective extraction method for obtaining lignan-containing fractions from flaxseed with a satisfactory yield of SDG-containing fraction and its isomers. This method was implemented by microwave irradiation pretreatment of the seeds and by using environmentally friendly extraction solvents. A 50/50 mixture of water and ethanol was chosen as extraction agents. Microwave irradiation pretreatment of ground flaxseeds was carried out at 450W and 800W for 5 seconds, 4 times with an interval of 5 seconds. SDG-identification was performed on an Agilent 1200 series high performance liquid chromatograph and a Shimadzu UV-1900 automatic dual-beam UV spectrophotometer. The results of the conducted studies showed that the microwave irradiation pretreatment of flaxseeds at 800W increases the yield of SDG relative to the dry residue by 34.76% in comparison with the classical alkaline method, and the content of the amount of lignans in recalculation on chicory acid was 43.53%. Thus, the extraction method of lignans-containing extract including the stage of pretreatment by microwave irradiation with power of 800W is the most effective method.