Study On The Volatile Compounds Of Lou Onion Based On The Intervention Of Preharvest Substances

Lou onion(Afistulosum L.var.Viviparum Makino)is a characteristic of arid regions in central Ningxia.In this study,the volatile flavor compounds of Lou onion from six different planting areas in Guyuan,Wuzhong and Zhongwei were analyzed by gas chromatography-ion mobility spectroscopy(GC-IMS),the best planting area of Lou onion was selected Secondly,the optimum treatment dosage was determined by analyzing the change of volatile matter after Lou onion was treated with different substances.Finally,the optimal treatment dosage of scallion was cut and the volatile matter of its pseudo-stem and tubular leaves were determined to distinguish the difference of the two main edible parts of the volatile matter under different treatment The purpose of this study is to provide a theoretical support for the evaluation of volatile compounds and quality improvement of the dominant cultivars of Lou onion in Ningxia.The main research results are as follows:(1)The volatile compounds of Lou onion from six plantin areas in three cities of Ningxia were analyzed by GC-IMS(Guyuan City:Xiji County,Longde County;Zhongwei City:Haiyuan County,Zhongning County;Wuzhong City:Tongxin County and Hehe Shan village),the results showed that 41 volatile compounds were identified in six planting areas,including 15 esters,4 alcohols,2 Aldehydes,3 ketones,4 phenols and 13 others.Comparing the characteristic peak areas of volatile compounds in different planting areas,it was found that the characteristic flavor sances of Lou onion in Wuzhong Tongxin County were the most abundant,containing 23 volatile sances in total,mainly including esters,aldehydes,alcohols,phenols,other five categories.Compared with other planting areas,the planting area has more species and bigger peak volume,which can be used as the dominant planting species of legume onion.(2)After the intervention of water-soluble silicon water-soluble silicon potassium and biological selenium,39,41 and 48 volatile compounds were identified.There were 3 characteristic sances in the samples of Lou onion after the intervention of water-soluble Silicon,1 characteristic sance in the samples of Lou onion after the intervention of water-soluble silicon and potassium,and 11 characteristic sances in the samples of Lou onion after the intervention of biological selenium.The optimum concentrations of water-soluble silicon,water-soluble silicon potassium and biological selenium were 600,3000 and 400 times,respectively.(3)The volatile compounds in the stems and leaves of Lou onion were analyzed by GC-IMS combined with fingerprint.A total of 45 substances were identified from the pseudostems,including 11 esters,4 alcohols,6 Aldehydes,5 ketones,4 phenols and 15 other species,there are 12 esters,3 alcohols,6 aldehydes,4 ketones,4 phenols and 12 others.There were 16 and 13 characteristic species identified from pseudostems and tubular leaves,respectively.Si-k 3000x was the best for pseudostem and Si 600x was the best for tubular leaf.