Extraction Of Flaxseed Oil And Secoisolariciresinol Diglucoside From Flaxseed

Flax(Linum usitatissimum L.) is an important oilseed crop all over the world. In addition to its industrial uses, flaxseed oil has been investigated for its medicinal potential and nutritional value. In flaxseed, secoisolariciresinol diglucoside (SDG) is effective in preventing and delaying a variety of chronic diseases including breast and colon carcinogenesis, atherosclerosis, diabetes mellitus and hyperlipoproteinemias. Due to growing environmental, economic and nutritional concerns over the use of hexane to extract edible oils from oilseeds, extraction processes using water as the separation medium are being explored. An aqueous enzymatic process assisted by ultrasound extraction (AEP-UE) was applied to the extraction of oil from flaxseed(Linum usitatissimum L) in this study. And then underpressure ultrasound-assisted extraction (UUE) was applied to the extraction of SDG and total polyphenol (TP) from these defatted flaxseed.1. GC-MS analysis of flaxseed oil were performed using a Varian450-GC/240-MS gas chromatography/mass spectrometer (Varian, Santa Clara, CA, USA), equipped with a HP-5silica capillary column (30m×0.32mm i.d.; film thickness0.2μm). Helium was used as carrier gas and the split ratio was1:20. Mass units were monitored from m/z50to600. Compound separation was achieved following a linear temperature program of120℃(1min),120-240℃(5℃/min),240℃(10min), so the total run time was35min.JASCO PU-1580(Japan) HPLC equipment with UV-1575UV/VIS Detector and Millennium32software was used for analysis SDG The separation was performed at30℃on an Ultimate HPLC column XB-C18(5μm,4.6×250mm, Welth Materials, Ellicott City, MD, U.S.A.). The injection volume was10μL. The mobile phase was methanol-water (27/73, v/v). The separation was performed at a flow-rate of1mL/min. Effluent was monitored at280nm UV wave-length.2. Flaxseed degumming process parameters were optimized.The highest gum recovery of64±1.1mg/g was obtained when ground flaxseed was extracted under120rmp/min magnetic stirring for20min, at20℃and solid to liquid ratio1:20.3. The highest oil recovery of68.1%was obtained when ground flaxseed was incubated with130U/g of cellulase, pectinase, and hemicellulase for12h, at45℃and pH5.0. After a single-factor design to optimize aqueous enzymatic process, the effects of incubation time, incubation temperature, pH value and enzyme cocktail concentration on oil extraction yield obtained by immobilized enzymes, was evaluated by principal component analysis (PC A). The IC50values of oil obtained by AEP-UE and organie solvent extraction (OSE), as measured by DPPH scavenging activity essay, were2.27mg/mL and3.31mg/mL. Aqueous enzymatic extracted oil contained15.4±0.1%omega-6-fatty acid and63.7±0.3%omega-3-fatty acid. Percentages of both mono unsaturated fatty acid and poly umaturated fatty acid are higher in aqueous enzymatic extract in comparison to the conventional solvent methods (P<0.05). The AEP-UE-derived oil had a1.5%higher content of unsaturated fatty acids than the OSE-derived oil. The immobilized enzymes can be reused, resulting lower processing costs then when free enzymes are used. AEP-UE is therefore a promising environmentally friendly method for large-scale preparation of flaxseed oil.4. The highest extraction yield of SDG and TP (9.2±0.1and15.2±0.3mg/g) was obtained when defatted flaxseed was extracted for30min,100%power rate, at45℃, underpressure-0.08MPa,80%ethanol and solid to liquid ratio1:30. The IC50value of crude extracts of UUE method and that of standard heat refluxing extraction were1.55±0.01and2.17±0.02mg/mL, respectively. The UUE-derived extracts had higher content of SDG and TP than the conventional extraction method. UUE is therefore a promising environmentally friendly method for large-scale preparation of extracts rich in SDG and TP.