The Separation And Identification Of Colored Substances In Rice Bran Oil And Its Application

As a kind of healthy edible oil,rice bran oil has balanced fatty acid ratio and contains bioactive substances such as γ-glutamine,phytosterols,squalene,vitamin E,polyphenols and flavonoids,but the color of rice bran oil is too dark and difficult to remove.Since the color of the oil directly affects its stability and quality,this paper focuses on the extraction and separation method of the color-presenting substances of rice bran oil and the identification of the color-presenting substances to provide a basis for improving the stability,edible quality and commercial value of rice bran oil.Firstly,the coloring substances are divided into polar part and non-polar part according to the polarity size,and the coloring substances of both parts are extracted by liquid-liquid extraction and solid-phase microextraction methods.According to the L*a*b* values of the coloring substances,the method of extracting the coloring substances in the sample was determined as follows: firstly,the coloring substances in the polar part of the sample were extracted by liquid-liquid extraction with methanol: water(8:2,v/v),and then the coloring substances in the non-polar part were extracted by liquid-liquid extraction with n-hexane.Next,the chromogenic substances were separated and purified for identification.The coloring substances were initially identified as flavonoids by chemical reagent method,and the coloring substances were separated by high performance liquid chromatography,and the coloring substances were identified by electrospray time of flight mass spectrometry.Finally,the coloring substances of rice bran oil contained 3 kinds of flavonoids,3 kinds of isoflavonoids,4 kinds of flavonols,3 kinds of arylbenzofuranoflavones,5 kinds of biphenylpyroquinone,1 kind of anthraquinone,6 kinds of carrot,and the content and kinds of coloring substances in the weak polar part were surplus to the strong polar part.Finally,the pigment extraction and identification method was applied to test and identify the coloring substances in flaxseed oil,and the results were that one kind of anthraquinone,three kinds of isoflavones,four kinds of flavonols,two kinds of chalcones,one kind of aryl benzofuran flavones,one kind of chlorophyll,and 10 kinds of carotenoids of flaxseed oil samples were known.Using the DPPH method to determine the ability of the color-presenting substances of rice bran oil,linseed oil,peanut oil and corn oil to scavenge lipid free radicals,the results were that the color-presenting substances in the weakly polar part had a stronger ability to scavenge lipid free radicals than the color-presenting substances in the strongly polar and strongly polar part,and the order of scavenging lipid free radicals was rice bran oil,linseed oil,peanut oil and corn oil in descending order.