Quantitative Optimization Of Volatile Oil Extraction From Tobacco Leaves And Volatile Oil In The Initial Stage Of Sun-cured Tobacco

Sun-cured tobacco has a long history and variety in China.It is an important raw material for developing low coke and reducing harmful Chinese cigarettes,especially mixed cigarettes.As an important component of flue gas quality,sun cured volatile oil has complex components and affects the appearance quality of tobacco leaves.It is important to understand the change trend of the volatile oil content in the process of sun smoke modulation,especially the change of the content of the plant alcohol and the new diene,which is important for the understanding of the relationship between the modulation and the quality of the tobacco.This study first explored the quantitative determination of volatile oil in tobacco leaves by ultraviolet spectrophotometry,and then optimized the method parameters of the simultaneous distillation extractor and the extraction of volatile oil.The dynamic sampling was used to analyze the changes in the main aroma substances in the regular modulation of the sun smoke,and the reactive oxygen species and the tobacco leaves during the modulation were explored by the formula of H₂O₂ and NO.The relationship between the main components of volatile oil and the contents of plant alcohol and new plant diene.The main results are as follows:1.In ultraviolet light range,the volatile oil solution of tobacco leaves is red shift with the increase of concentration,but its concentration has the best linear regression relation with the absorbance at wavelength 239nm（R²=0.9993）,and its linear regression equation has good stability and reliability,which can be used in quantitative tobacco volatile oil content.2.The highest extraction efficiency of the 6 hole receiving inner tube was determined by the single heat source simultaneous distillation extractor.Through the orthogonal experiment,the effects of the single heat source and the distillation extractor of the 6 holes in the extraction of the volatile oil of the tobacco leaves were determined as follows:the amount of sodium chloride>the extraction time>the ratio of the material liquid;the optimum extraction parameters were the ratio of the material to liquid,respectively.At1:25,the amount of NaCl was 40 g and the distilling time was 3h.3.A gas chromatography-mass spectrometry（GC-MS）instrument was used to determine the volatile oil components in the yellowing phase of the cured tobacco leaf.1)Solanone increased rapidly in the late stage of yellowing,and the main carotenoid degradation substances reached the maximum in the later period of the modulation of yellowing;2)In the 1-7d,there was chlorophyll degradation in the tobacco leaf.However,a large number of alcohols were not seen,and the content of new dienes was low;in 7-13d,the basic chlorophyll degradation and the content of new diene increased significantly,and the correlation of the two was very high.In the path of"chlorophyll plant alcohol new plant diene",there is still unknown pathway for rapid transformation of plant alcohol.4.With the addition of low concentration of NO,the chlorophyll degradation of the exposed tobacco leaves is slower,and the high concentration of NO will accelerate the degradation of chlorophyll,and the chlorophyll degradation rate is faster than that of the NO spraying leaves during the spraying of H₂O₂.Compared with the NO leaves,the phenols in the leaves of the spraying H₂O₂ are greatly reduced and the leaf color is more yellowing,Darkened.Reactive oxygen species can regulate the transformation process of tobacco leaves during the modulation period and improve the modulation effect of tobacco leaves.