Study On The Structure-activity Relationship Between Nutrients And Antioxidants In Flaxseed Oil

Flaxseed oil contains a variety of endogenous antioxidant active substances,such as polyphenols represented by flax lignans,tocopherols,carotenoids,cyclic peptides and so on.In this experiment,the physicochemical indexes of self-extracted linseed oil were determined.Determination of Secoisolariciresinol Diglucoside（SDG）,γ-tocopherol andβ-carotene in self-mentioned commercially available flaxseed oil by DPPH method,FRAP method,ORAC method and Q¹O₂ method.The ability of three antioxidants to scavenge lipid free radicals,reduce variable valence metal ions,scavenge total reactive oxygen radicals and quench singlet oxygen was determined by the three antioxidant methods.The antioxidant capacity of the elements was analyzed.In the experiment,the interaction between the three antioxidants and the oxidation trend of linseed oil were also detected and analyzed,and the oxidation kinetic equations of SDG,γ-tocopherol andβ-carotene in the linseed oil system were determined,and the results were obtained.The shelf life of linseed oil is predicted.The contents of SDG,γ-tocopherol andβ-carotene in self-extracted flaxseed oil were determined by high performance liquid chromatography,which were 163.72 mg/kg,360.90mg/kg and 3.29 mg/kg,respectively,which were higher than those of commercial flaxseed.Oil（75.30 mg/kg,188.84 mg/kg,3.18 mg/kg）.In DPPH assay,γ-tocopherol has the best ability to scavenge DPPH·,and its EC50 value is 46.49μmol/L;in FRAP,SDG has the best ability to reduce Fe³⁺,when c _SDG=50μmol/L,its The amount was 114.76μmol TE/L;in ORAC,SDG had the best ability to scavenge total oxygen free radicals,and its ORAC value was 4.09;in Q¹O₂,when cβ_-carotene=100μmol/L,¹O₂ quenched The rate was 24.2%,of which SDG andγ-tocopherol had no obvious quenching activity.In the combined antioxidant experiment,onlyγ-tocopherol andβ-carotene had obvious synergistic effect in ORAC experiment,and the other experimental groups showed additive effect or very insignificant antagonistic effect.In the experiment,it was determined that the free radical reaction in linseed oil completed the chain initiation process and proceeded to the propagation stage within 0-1 h of heating at 60°C,and a large amount of LOO·accumulated within 1-2 h of heating,and all anti-The residual amount of oxidant in the system was extremely low after heating for 2 h.When the antioxidant model was 400μmol/L SDG-188.84 mg/kgγ-tocopherol-100μmol/Lβ-carotene,the shelf life was extended by 50.13 days compared to blank flaxseed oil.