Research On Refining Technology And Antioxidant Of Flaxseed Oil

Flaxseed oil contains large amounts of unsaturated fatty acids, which was easily oxidized. The conditions of hexane solvent extraction on flaxseed oil was investigated. And cold-pressing and hexane solvent extraction on flaxseed oil was refined. The effect of temperature, sunlight and oxygen, antioxidant and synergistic agent on peroxide value of flaxseed oil was studied in this paper. All of above was done in order to provide the theoretical basis to the preservation and delay the oxidation of flaxseed oil.1. On the basis of single factor tests, orthogonal test was designed. And the effects of ratio of material to solvent, extraction temperature, extraction time on yield ratio of flaxseed oil were investigated. The results showed that the best extraction conditions were admini-strated:extraction temperature60℃,ratio of material to solventl:14and extraction time70min. Under these conditions, the yield ratio of flaxseed oil reached42.82%.2.The optimal levels of degumming,deacidification, decolorization of cold-pressing flaxseed oil were studied. In this condition, hexane solvent extraction on flaxseed oil was refined. The optimum processing technology parameter of refining was administrated:(1)The optimal levels of cold-pressing flaxseed oil degumming were found to be:amount of phosphorice acid of0.5%and water of3.0%used for30min degumming at65℃,degum-ming ratio of cold-pressing flaxseed oil reached84.19%.In this condition, degumming ratio of hexane solvent extraction flaxseed oil reached82.16%.(2)The optimum conditions for the deacidifying process of cold-pressing flaxseed oil was obtained, such as ultra-alkali of0.25%,NaOH mass fraction of14%, temperature of55℃and processing time of30min, deacidifying ratio of cold-pressing flaxseed oil reached85.10%.In this condition, deacidifying ratio of hexane solvent extraction flaxseed oil reached84.2%.(3)The optimum reaction conditions of cold-pressing flaxseed oil decolorization were de-termined as follows, amount of activated carbon of6%, decolourization temperature of70℃, decolorization time of35min,decolouring ratio of cold-pressing flaxseed oil reached80.16%. In this condition, decolouring ratio of hexane solvent extraction flaxseed oil reached77.73%.3. The influence of temperature, sunlight and oxygen on peroxide value of flaxseed oil was studied. The results showed that in the flaxseed oil oxidation process, the higher temper-ature was, the faster peroxide value of flaxseed oil increased, With the sunlight time extended, the flaxseed oil peroxide value increased rapidly.4. The effects of TBHQ, TP and VE on antioxidant effect of flaxseed oil were studied by Schaal oven method. The results showed that all these antioxidants had certain antioxidant effect to flaxseed oil. And the antioxidant capacity was TP>TBHQ>VE.TBHQ or with CA or Vc exhibited significant antioxidation ability. Added with0.02%TBHQ and0.02%CA or0.02%and0.02%Vc in the flaxseed oil can effectively delay the flaxseed oil oxidizing dete-rioration.