Study On The Relationship Between Aroma Compounds And Chemical Quality Of Flue Cured Tobacco In Qinling Mountains

Chemical components,moderate and micro elements and aroma components of 3 main varieties of flue cured tobacco,which were K326,QY96,YN99,from 3 main tobacco growing areas(contain Luonan,Yangxian,Xunyang)in Qinling Mountains were determined.And the relationship between moderate and micro elements,chemical components and aroma components were analyzed.At the same time,the relationship between the content of potassium,chlorine and aroma compounds were analyzed emphatically.This paper was expected to provide theoretical reference for improving the internal quality of flue cured tobacco in Qinling Mountains.Main results were as follows:(1)The potassium content was low with 93.59 % of samples was below the threshold of 2.5 %.Compaired with QY96 and YN99,K326 had more appropriate potassium content,while only 5.56 % of K326 samples was within the suitable range;The chlorine content was low with the higher variation coefficient of 83.18 %,and 61.54 % of samples was below the threshold of 0.3 %.According to the chlorine content of flue-cured tobacco,the three genotypes could be arranged as follows: YN99>QY96>K326;The potassium chlorine ratio had the largest variation coefficient(121.16 %)among these all of chemical indicators,with 60.26 % of samples was above the threshold of 4;While the contents of other conventional chemical constituents were suitable.According to the comprehensive fitness index of chemical composition of flue-cured tobacco,the three genotypes could be arranged as follows: K326>YN99>QY96.As to the moderate and micro elements,the calcium content was high while the zinc content was low with most samples was below the suitable range.While the contents of other moderate and micro elements were suitable.(2)Close relationship was exist between moderate and micro elements and conventional chemical constituents in Qinling Mountains.Total sugar and reducing sugar existed extremely significant negative correlation with calcium and iron;The total alkaloid,chloride existed significant negative correlation with iron,copper;The potassium exists the significant or extremely significant correlation with manganese,calcium,iron and magnesium;The potassium chlorine ratio exists the significant positive correlation with calcium and iron,and sugar nitrogen ratio exists the significant negative correlation with calcium and iron;The ratio of total sugar to nicotine exists the significant positive correlation with copper.(3)59 kinds of aroma compounds were detected in flue-cured tobacco samples from Qinling Mountains.The result showed the trend of Chlorophyll Degradation Products>Phenylalanine Degradation Products > Cembratriendiol Catabolite >Carotenoid Degradation Products>Browning reaction.Browning reaction,Phenylalanine Degradation Products,Chlorophyll Degradation Products and Carotenoid Degradation Products were the principal composition of aroma substances in flue cured tobacco around Qinling Mountains.The assessment result gained by the comprehensive score model showed that according to the aroma quality of flue-cured tobacco,K326 was the best.(4)Correlation relationship was exist between chemical constituents and aroma components in Qinling Mountains.Total sugar,reducing sugar,potassium and iron,manganese exist the significant or extremely significant correlation with most of the key aroma compounds.While other chemical indicators are only related to some aroma substances.The cluster analysis showed that there was a certain relationship between potassium,chlorine and aroma components.The highest potassium content group had the highest content of degraded products from cembranoids,carotene,phenylalanine,browning reaction.Medium chlorine flue-cured tobacco had the highest content of degraded products from chlorophyll and carotene.while other aroma substances were the lowest.