Effects Of Waterlogging On The Quality Of Sesame Seeds And Products

Sesame is a high quality oil crop in China.Many factors such as diseases,water-logging and droughts,affected the sesame yield and quality in current sesame production.In the main sesame production regions,sesame always suffers rainstorm or continuous rainfall,and the output of sesame would be greatly reduced accordingly.In order to study the effect of waterlogging on the quality of sesame and its products,the continuous waterlogging treatment was carried out.We selected water-logging sesame seeds as raw materils.Firstly we studied about the yield and appearancequality of sesame seeds under the different time of water-logging treatment.To further explore the variation of nutritional components in sesame seeds under the water-logging treatment,it was analyzed by the changes of the quality of the sesame,sesame oil and sesame paste under the water-logging treatment.It provided a basis for guiding the high value production and processing of sesame The study results were as follows:(1)The effects of different water-logging lags on the agronomic characters and appearance quality of sesame seeds were studied.The results of agronomic traits showed that the plant height,effective axis length,effective node number,capsule number per plant and yield per plant of sesame were lower than those of control group(0 h).The difference was significant between them.The degree of decline increased with the prolongation of treatment time.But it had no effect on the length and width of sesame seed Furthermore,sesame seed color became darker though the different time of water-logging.The content of 1000 grain weight was reduced.(2)The effect of different lags of water-logging on the nutritional components of sesame seeds was studied.Compared with the control group of 0 h,the crude fat content of sesame decreased,the total sugar and crude fiber content increased,and the protein content showed a trend of high-low-high.A comprehensive evaluation of 5 groups on the quality of sesame seeds was conducted.It was found that the control group(0 h)was best and 60 h water-logging treatment was the worst.Grey correlation analysis was used to analyze 7 quality indexes under the 36 h water-logging treatment.It was found that sesamin content was influenced greatly(1.38)and ash content was influenced leastly(0.36).(3)The changes of quality of sesame oil after the water-logging treatment was studied.Making use of 4 kinds of sesame,such as Yu Zhi 11,to make cold oil and hot oil respectively Both the acid value and the peroxide value of the sesame oil of different varieties were increased between cold pressed oil and hot pressing oil.It ranged from 13.64% to 146.75% and from 14.04% to 290.48% The content of sesamin,sesamolin,sterol and vitamin E of beneficial ingredients was decreased.It ranged from 0.90% to-18.06%,-0.13% to-29.77%,-0.56 to-13.58%,-9.44% to-13.58%.Some sesame was different because of varieties.For example the content of ji9014 was different from that of the other 3 sesames.The oxidation induction time caused shorten at the same time,which is unfavorable to the storage of sesame oil.Compared with the change of fatty acid composition after the water-logging treatment between cold and hot sesame oil.The study showed water-logging treatment did not change the composition of fatty acid in sesame oil,but the relative content of fatty acid composition varied.The palmitic acid content was reduced.The oleic acid content was increased.The linoleic acid content was reduced.It ranged from-9.81% to-0.02%,0.41% to 10.82% and-8.95% to 1.27%.And the other fatty acids varied in different degrees.Moreover,the trend of fatty acids in the Sn-2 position was the same as that of all kinds of fatty acids.(4)The changes of the quality of sesame paste under waterloggig conditions were studied.With the prolongation of waterlogging treatment time,The changes of the basic physicochemical index were line with that of sesame and sesame oil Compared with the control group(0 h),it reduced the ratio coefficient of amino acid of sesame,and affected the nutritional value of protein.But the viscosity,hardness,viscosity tahina aggregation and particle size was not affected by waterlogging treatment.It showed that waterlogging treatment reduced the overall acceptability of sesame paste through the analysis of sensory evaluation and volatile components.