The Effect Of Sesame Varieties And Processing Technologies On Quality Of Sesame Oil And Sesame Protein

In recent years, as the demand of sesame increased rapidly of our country, the number of sesame imports was increasing. At the same time there arised many processing technologies of sesame oil and cold pressing technology. Because of the different of sesame varieties and technology conditions, the quality of sesame processed products were different. So the effect of sesame varieties and processing technology was studied on the quality of sesame products.It was highly significant for improving the processing technology of the sesame and the quality of its processed products and increasing the added value of sesame and developing the industrial of sesame.In the paper,the sesame was researched as raw materials. The effect of different sesame varieties and places(domestic and import) was studied on the quality of sesame's product. The results showed that the oil of white sesame was 54.99% which was the highest,but the protein,seed coat,ash,cellulose and oxalic acid contents were low.It also showed that domestic sesame had higher oil content and lower oxalic acid and ash content than import sesame. The flavor of domestic sesame oil was pure and the color of domestic sesame oil was lighter than import sesame oil .The acid value and peroxide value of domestic sesame oil were lower. The antioxidant content of domestic sesame oil was higher and the oxidation stability was better. The effect of technologies for processing sesame fragrance oil on quality of the products was notable. It showed that acid value and peroxide value of screw pressed sesame oil were the highest. The color of sesame oil in queous extraction method was deepest(Y70R10.2). The water and volatile matter(0.15%) and sesamol of the oil were the highest. But the acid value and peroxide value were the lowest. The tocohperol and sesamin (170mg/100g) were the lowest. The oxidation stability of the sesame oil obtained by queous extraction method was the best and the induction time could reach more than 23 hours. The flavor and colour of sesame meal were bitter taste and deep color.The effect of the sesame'products made by cold pressing technology and the functional properties of sesame protein was studied. The results showed that the cold pressing sesame oil had light color(Y6.0R0.3) and the sesamin was 590mg/100g, but the oxidation stability is bad. The induction time was only 4.87h. Comparing to the oil of the whole sesame, the acid value of intact sesame oil was low,but the peroxide value was high. The content of cold-pressed peeling sesame protein was 43.39%,the value of NSI 25.77% ,the residual oil 26.01%, and its functional properties were not as good as peanut protein and soybean protein. After the influence of roasted conditions on sesame oil's quality and oxidation stability was studied, the results indicated that the color of sesame oil was deeper when the roasted temperature was higher and the roasted time was longer. Its acid value and tocohperol and sesamin decreased,but its peroxide value and sesamol increased. The oxidation stability of the sesame oil became better. The results of organoleptic evaluation for the fovor of sesame oil showed that the best roasted conditions were roasted temperature 200℃and roasted time 20-30 minutes.The sesame fragrance oil was studied by constant temperature deposition refining and degumming. It showed that the suitable conditions of deposition were 20 to 30 days at 10℃and 10 days above 15℃. The optimized conditions of degumming were the hydration temperature 50℃, 1g H2O(2 times of oil's phosphlipid content ) and NaCl 0.05% of oil. Comparing to the deposition oil with the degumming oil, the fovor of deposition oil was stronger,but the phosphlipid content of degumming oil was 0.007% lower than deposition,the transparence of the degumming oil was better. Besides, the deposition of sesame oil was rich in oil which was about 75%. And it contained protein, phosphlipid and wax.