Subcritical Compound Solvent Extraction Of Multiple Components From Flaxseed Meal And Characterization And Antioxidant Activity Of Flax Lignan Derivatives

Flaxseed contains about 40% flaxseed oil.The main utilization of flaxseed in my country is to produce flaxseed oil,and the remaining flaxseed meal will be discarded after the oil is produced.However,flaxseed meal still contains a variety of beneficial substances,and tens of thousands of tons of discarded materials every year will not only waste resources,but also cause serious environmental pollution.In this paper,a method for subcritical extraction of various components in flaxseed meal was studied,and three natural products of flax lignans,flaxseed oil(FO)and flax polysaccharides could be simultaneously obtained through one extraction.The lignans were isolated and purified for characterization and biological activity evaluation,and the fatty acid composition and cyclic peptide content in FO and the content of flax polysaccharide in the extracted material were analyzed.The main results are as follows:(1)Taking the total phenolic content as the response value,a response surface optimization experiment was designed based on the single factor test results to obtain the optimal conditions for subcritical extraction(anhydrous ethanol addition of 200 m L,extraction temperature of 69.0 °C,extraction time of 2.0 h),and the total phenolic content at this time was obtained.was 22.76 mg/g,and the extraction rate was 54.88%.Meanwhile,the effect of subcritical composite solvents was verified using the Hansen solubility model.(2)After purification and hydrolysis of the sample with SDG purity of 6.92%,high performance liquid chromatography,liquid mass spectrometry,infrared spectroscopy and nuclear magnetic resonance spectroscopy were used to confirm the purified product of flax lignans,and the purity of about 94% was obtained SDG and 95% pure SECO.(3)The fatty acid and glyceride composition analysis of FO found no significant difference between subcritically extracted FO and other FO.The content of cyclic peptides in subcritical extraction of FO is slightly higher than that of commercial FO,but significantly lower than that of traditional ethanol extraction of FO.Comparing the polysaccharide content before and after extraction,it was found that the two were basically the same.The morphology of the material before and after extraction was observed by scanning electron microscope,and it was found that the subcritical extraction was beneficial to the mass transfer during the extraction process and facilitated the dissolution of the material from the meal.(4)Using a series of in vitro antioxidant evaluation systems of DPPH,ABTS,FRAP,ORAC and PSC,combined with two breast cancer cell models,the antioxidant activities of SDG and SECO were studied.The combined results showed that the activity of SECO was superior to that of SDG.In this study,flaxseed meal was turned into treasure through green extraction,and the by-products of flaxseed oil were comprehensively utilized to obtain a variety of high value-added products,which provided a basis for further expanding the processing and utilization of flaxseed meal.