The Development And Application Of Varieties Traceability Technology Of Sesame Oil

The Sesame oil, commonly known as "balm", is famous for the rich mellow flavor. As one of the traditional cooking oil in our country, the Sesame oil have not only high nutritive value and unique flavor but also rich vitamin content and lower cholesterol, containing essential fatty acids, amino acids and trace elements loved by people such as iron, zinc, copper. In recent years, with the improvement of people’s living standard, the demand for sesame oil is increasing in our country, such as high price of sesame oil mixed with heterogeneous cheap vegetable oils or impurities. The quality is uneven and safety problem has been a cause for concern accompany with a variety of sesame oil production process. Using molecular biology techniques for cultivar identification and adulteration detection of cooking oil is a new detection method, mainly used in genetically modified, identification of variety and the phenomenon of adulteration in edible oil. However, edible oil DNA extraction is the key to molecular biology research. In this paper, the main research results are as follows:Combining with several kinds of commonly used DNA extraction method, this study screened out the oil DNA extraction kit method finally and established a highly efficient, rapid and simple sesame oil DNA extraction method. The results showed that the optimal oil dosage was 4 mL. 4 mL chloroform and 2.5 mL sodium chloride were selected for the degreasing buffer and lysis buffer respectively, the best mixing time and mixing speed were 50 min and 25 r/min. The ANOVA analysis was performed and statistical significance was determined with the mixing speed.In this paper, EST-SSR molecular markers were used respectively to this study to identify seven different varieties of sesame oil. In view of the seed and leaf DNA, 25 pairs of primers could amplify the ideal stripe and the amplification efficiency is 100%, but the sesame oil is 96%. The results of 18 pairs of primers are all the same for the sesame seed, leaf and oil DNA. It illustrates 18 pairs of primers can be used to SSR analysis of sesame oil DNA. RMAPD, a combination of RAPD and SSR molecular markers, can effectively reveal the polymorphism. Therefore, this study use RMAPD molecular markers combined with polyacrylamide gel electrophoresis method to carry out the cultivars identification among the six varieties of sesame oil, the results show that 4 pairs of primers such as RA1-HS61 F, RA1-HS62 F, RA1-HS62 R, RA1-HS63 R, in the selected 8 pairs of RMAPD primers, can distinguish 6 sesame cultivars. RA1-HS61 F, the best primer, not only can distinguish the different origin of sesame cultivars, but also can distinguish the Zhuzhi 20 with the Zhuzhi 19 and Jinzhi 3 with Fenzhi 2.This study establishes a rapid and efficient sesame oil adulteration detection method by qPCR qualitative and quantitative analysis. The results show that the S199 primer has a good specificity. With the help of S199, BnA136 and L109, the specific identification of three kinds of vegetable oil is remarkable and reveals difference among Tm values. In addition, this study established a quantitative linear equation to calculate the amount of sesame oil adulteration: Y=-3.139lg(x)+20.06, R2=0.998, E=1.08. The result of relative quantitative detection found that being adulterated soybean oil, the higher sesame oil DNA content, the smaller Cq value. So, the longer sesame oil storage time, the lower sesame oil DNA content. We should pay attention to storage-time of sesame oil to obtain accurate results in the future.