| Sesame is an important high-quality oil crop in China.However,sesame is affected by a number of factors during its growth.Among them,sustained drought stress has a greater impact on the growth of sesame.Especially in recent years,the high temperature and drought(7-10 days)during the growth of sesame occurred in the main sesame producing areas in China.This has led to atrophy of sesame and a decline in fruit,which ultimately affects yield and quality.Therefore,this paper studied the quality changes of different varieties of sesame under single water and drought conditions.At the same time,the quality,nutrient characteristics and flavor changes of sesame under different drought coupling conditions were further analyzed in a certain range.It provides a theoretical basis for the formation of sesame and the improvement of quality products under drought treatment.The research results are as follows.(1)Single water control drought test results show that the five yield related traits of 12 varieties,i.e.,plant height,capsule stem length,capsule number per plant,seed yield per plant and thousand seed weight(TSW),varied under the drought stress.Of which the seed yield per plant decreased by 2.31%~23.8%.The ?E-value of seed color of samples varied from 0.96-3.30,and the seed coat color of treatments got dark.The variation extents of oil content and protein content were from-0.72%~4.03% and-5.77%~4.12%.The variation of polyphenol content was-21.92%~33.00%,while the variation of FAPR(ferrous reduction power value)was-24.88%~73.92%.The significance of difference analysis indicated that the effects of environmental factor(drought stress)on sesame traits of TSW,oil content,FRAP value were significant(P<0.05),while its effects on sesamolin content and polyphenol content were evidently significant(P<0.01).Moreover,the significantly positive correlation of sesamolin content and polyphenol content and antioxidant capacity was found.(2)15 kinds of drought coupling treatment(drip irrigation time,fertilization amount and density)were selected from Yuzhi DW607 of 12 varieties.Further evaluate the impact of the arid environment on the quality of sesame.The study found that the change in seed coat color is the main change in the appearance quality of sesame seeds under 15 drought-coupled treatments.When the degree of drought is large(drip time 1h),the ?E values are 1.02,1.45,and 1.23.There were significant differences(P<0.05).The color of the sesame seed coat is deepened.In terms of dry matter accumulation,the maximum content fluctuation range under the 15 drought-coupling treatment conditions was crude fat content,crude protein content,total sugar content and crude fiber content.Different drought degrees(drip irrigation time)were significantly correlated with crude fat and protein content(P<0.01).At the same time,the crude fat content was the lowest value between the groups under drought coupling treatment conditions 1,6,and 11(drip irrigation time 1h fertilization amount 70%).The results showed that the content of oleic acid(C18:1)in fat showed a downward trend in the three groups,and the linoleic acid(C18:2)group showed an increasing trend.However,there were no significant differences in NSI values and major amino acid composition and content changes of sesame protein under 15 drought conditions(P>0.05).In terms of anti-nutrition,the phytic acid content of defatted sesame in 15 drought-coupling treatments ranged from 78.62 mg/g-86.49 mg/g.The tannin content ranged from 2.46-2.68 mg/g.Correlation results showed that different degrees of drought(drip irrigation time)were significantly correlated with phytic acid content in sesame seeds(P<0.01).However,there was no significant correlation between tannin content(P>0.05).(3)Further analysis of the effects of drought-coupled environment on the antioxidant capacity of sesame.There was a significant correlation between the degree of drought(drip irrigation time)and the total phenolic content in sesame seeds(P<0.01).There was a significant correlation between the content of sesamin and sesamelin in sesame skin(P<0.01).In terms of antioxidant capacity,the total antioxidant capacity,DPPH clearance rate and · OH clearance rate of FRAP values under 15 drought conditions were skin> grain>seed.The total antioxidant capacity of sesame seeds ranges from 12.43-24.87 ?mol/g.The average value was 16.47?mol/g.The rate of change was-24.56%~51.02% compared with the average;DPPH free radical scavenging ranged from 35.12%~53.15%.The average is 42.58.The rate of change was-17.53%~24.83% compared with the average;the OH removal range was 17.93%~22.76%.The average value is 19.69%.The rate of change was-8.93%~15.60% compared to the average.There were significant correlations between the different drought degrees(drip irrigation time)with the three antioxidant capacity experiments of sesame seeds(P<0.01).(4)The effect of the drought environment on the quality of sesame products was evaluated.The sesame seeds of No.11-15 in drought coupling were selected to prepare sesame oil and sesame sauce to analyze the flavor quality changes.The study found that the condition of No.11 that sesame oil was the darkest in color.The flavor species of sesame oil increased under the five degrees of drought coupling conditions with the decrease of drought degree.The total number is 67,70,72,77,and 124.At the same time,the percentage of pyrazines in the sesame oil of 5 ranges from 56.85%~68.20%.And with the decrease of drought degree,the pyrazines in sesame oil increased.On the other hand,there were no significant differences in sensory sesame sauce under five different degrees of drought coupling conditions.As the degree of drought decreased,the total number of flavor components was 52,52,80,137,and 164.The relative percentage of pyrazines is the highest,and the content ranges from 33.49%~45.39%.Pyrazines and aldehydes are the main volatile flavors of sesame.Under the five drought conditions,the flavor of sesame sauce increased with the decrease of drought degree.At the same time,the pyrazines showed an increasing trend with the decrease of drought degree,and the aldehydes showed a decreasing trend. |
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