The Study On Critical Extraction And High Value Utilization Of Wheat Bran Oil

In this paper,wheat bran was used as raw material,the yield of wheat bran oil was used as the test index,the parameters were optimized by single factor and Box-Benhnken Center Combination Response Surface test,the optimum technological parameters of subcritical extraction were obtained.The results showed that the extraction temperature was 40 ?,the extraction time was 30(min/time),the ratio of material to liquid is 1:3(g/ml/time),the extraction times are 3 times,and the oil extraction rate of wheat bran is higher,reaching 86.92%.In order to understand the quality of wheat bran oil,the routine physical and chemical indexes of wheat bran oil were determined firstly,and then the components of wheat bran oil extracted by subcritical extraction were analyzed by GC-MS.The results showed that the subcritical extraction oil had the inherent smell and taste of wheat bran oil,and its color and transparency were better,and it was light yellow with no large particles visible to the naked eye.The water content of oil was 0.34%,the acid value was 14.8mg/g,the refractive coefficient of oil was 1.4743,and the peroxide value was 0.14805 g/100 g.Before analyzing the composition of oil and fat,we must first determine the pretreatment method of oil and fat.By comparing the three pretreatment methods,the acid methyl ester was selected as the pretreatment method for the determination of oil composition.The total ion flow chromatogram of wheat bran oil was obtained,and the oil composition and relative content were analyzed.A total of 21 components were identified in wheat bran oil,of which 16 were fatty acid esters and 4 were sterols.Fatty acid esters account for 78.10% of the total components measured.The five fatty acid components with higher relative content are methyl palmitate,methyl linoleate,methyl oleate,methyl stearate and nine fatty acids.Methyl eicosapentaenoic acid,which accounted for 11.24% of the total component,accounted for 13.38% and2.01%.And sterols accounted for 19.42% of the relative contents of the total components,which were ?-sitosterol,lasosterol,rapeseed oil sterol and ergosterol,which accounted for 4.75%,8.91%,3.44% and 2.23% of the total components,respectively.The content of phytosterols in wheat bran oil was relatively high,and phytosterol was a functional active substance.Therefore,four common plant sterols in wheat branoil were quantitatively analyzed.The results showed that no rapeseed sterol was detected in the oil,and the other three phytosterols appeared in the order of rapeseed oil sterol>lasosterol>?-sitosterol.The contents of rapeseed oil sterol,soybean sterol and ?-sitosterol in wheat bran oil were 3446.565mg/kg,5346.34mg/kg and5845.46mg/kg respectively.Wheat bran oil obtained by subcritical extraction was wool oil and needed further refining.In this paper,the basic physical and chemical indexes,the relative content of fatty acid methyl ester and phytosterol,the phytosterol separation of light components of molecular distillation,and the purity of the crude oil in each refining process were determined by GC-MS.The results showed that the oil in each refining process had the inherent smell and color of wheat bran oil,and the transparency was better.After oil refining,water content,acid value and peroxide value reached the national hygienic standard of edible oil.It was found that the relative contents of five main fatty acid methyl esters in light component oils and five main fatty acid methyl esters in light component oils showed a general decreasing trend and that the relative contents of five main fatty acid methyl esters in light component oils showed an overall upward trend through the determinationof oil composition in each refining process.The relative contents of main plant sterols in the recombined oils showed a general decreasing trend,and the relative contents of the main plant sterols in the light component oils increased first and then decreased gradually.The purity of purified phytosterol was determined and the purity of phytosterol was 96.01%.Finally,the microencapsulation technique was used to treat wheat bran oil.The parameters of microencapsulated wheat bran oil were optimized by orthogonal experiment with sodium octenyl starch succinate and sodium caseinate as embedding materials.The quality evaluation and scanning electron microscope analysis were carried out to observe the morphology of microcapsules.The results showed that when the composite ratio of wall material was 1:1,the ratio of core to wall was 1:5,and the amount of emulsifier was 0.4g,the embedding rate of wheat bran oil microcapsule was higher,which was the best formula.Through the quality evaluation of fluidity,flushing and oxidation stability of microcapsules,it was found that the fluidity,flushing and stability of microcapsules were all good.The morphology of microcapsules was analyzed by scanning electron microscope.The results showed that most of the microcapsules were spherical in shape,smooth in surface,compact in structure,almostno cracks,and good in morphology.