Characteristics And Correlation Analysis On The Quality Of Flue-Cured Tobacco In Yibin

Taking the flue-cured tobacco from four tobacco planting counties of Yibin as the research object,the appearance quality,physical characteristics,conventional chemical composition,sensory evaluation quality and mainstream smoke composition of tobacco leaves from different tobacco planting counties were analyzed;The relationships between the conventional chemical components and appearance quality indexes,the conventional chemical components and sensory evaluation indexes,and the aroma substances and sensory indexes of Yibin tobacco were analyzed systematically;The relationship between the content of aroma compounds in tobacco leaves and that in flue gas was analyzed.The main results are as follows:1.Appearance quality analysis of Yibin flue-cured tobacco.On the whole,the color gamut of the upper,middle and lower leaves of Yibin flue-cured tobacco was orange and lemon yellow,and the maturity was mature;The upper and middle leaves of the blade structure are still loose,and the lower leaves are "loose";The identity score of Yibin tobacco leaves was slightly lower,and some of them were thinner or thicker;The results showed that the oil content of each part of tobacco leaves was "you";The chromaticity is of "strong" grade.The total score of appearance quality of upper leaves was Xingwen County>Pingshan County>Gong County>Junlian County,the total score of appearance quality of middle leaves was Xingwen County>Pingshan County>Junlian County>Gong County,and the appearance quality of lower leaves was Gong County>Junlian County>Pingshan County>Xingwen County.2.Analysis of physical characteristics of flue-cured tobacco in Yibin.The leaf thickness of Yibin flue-cured tobacco ranged from 78.48 to 150.92 μm.The results showed that the stem content was 27.22-33.94%,the leaf density was 42.28-127.61 g/m2,and the equilibrium moisture content was 10.29-14.49%.On the whole,the physical characteristics of Yibin tobacco were basically in the appropriate range.3.Routine chemical composition analysis of flue-cured tobacco in Yibin.The total sugar content of Yibin tobacco ranged from 16.6%to 36.6%,reducing sugar content from 14.5%to 33.2%,total nitrogen from 1.20%to 4.23%,nicotine content from 1.01%to 2.79%,potassium content from 1.35%to 2.62%,and chloride content from 0.03%to 0.81%;The contents of total sugar and reducing sugar in the middle leaves of Yibin tobacco were higher than those in the upper and lower leaves;The content of total nitrogen in lower leaves was lower than that in middle leaves and upper leaves;Nicotine content in upper leaves was significantly higher,potassium content in upper and middle leaves was slightly lower,and chloride content in tobacco leaves was lower.Overall,the total sugar content of upper leaves in Xingwen County was slightly lower than that in the other three counties,and the reducing sugar content of tobacco leaves in Pingshan County was slightly lower than that in the other three counties;The content of total nitrogen in Gong County was significantly higher than that in the other three counties,while the content of nicotine in Gong County was significantly higher than that in Pingshan and Xingwen counties;The contents of reducing sugar,total nitrogen and nicotine in Gong County were significantly higher than those in Pingshan and Junlian,and the ratio of potassium to sugar to nicotine in Xingwen was the highest;The contents of total sugar and reducing sugar in Xingwen County were relatively high,and the contents of total nitrogen in Gong County and Junlian county were relatively high.4.Analysis of aroma components in Yibin flue-cured tobacco.The content of neutral aroma compounds ranked from high to low as chlorophyll degradation products,carotenoids degradation products,cederanes degradation products,Maillard reaction products and phenylalanine degradation products;Among the degradation products of carotenoids,Gong County β-The content of dihydrodamascone was higher than that of megastigmatrienone B and megastigmatrienone D in Junlian county;In Maillard reaction products,the content of furfural was Junlian County>Xingwen County>Pingshan County>Gong County,the content of furfuryl alcohol was Junlian County>Gong County>Xingwen County>Pingshan County,the content of 5-methylfurfural was more in Gong County,Junlian county and Pingshan County,the content of 5-methylfurfural was relatively less in Xingwen County,the content of 2-Acetylfuran and 2-acetylpyrrole in Junlian county were the highest;In the degradation products of carotenoids,the content of benzaldehyde in Gong County is lower than that of other three counties,and the total amount of phenylalanine degradation products is the highest in Pingshan,and the total amount of phenylalanine degradation products in Gong County and Xingwen County is relatively small.The average content of neophytadiene was Xingwen County>Junlian County>Pingshan County>Gong County,and the average content of Solanone was Gong County>Xingwen County>Pingshan County>Junlian county.5.Sensory evaluation and smoking quality analysis of Yibin flue-cured tobacco.The overall performance of sensory evaluation indexes of tobacco leaves in Yibin production area was as follows:aroma quality of upper leaves was medium,middle leaves was better,and lower leaves was medium and worse;The results showed that the aroma content of each part was from sufficient grade,miscellaneous gas was from slight grade,aftertaste was from less comfortable grade to more comfortable grade,and irritation was from slight grade;The total sensory score of the middle leaf was the highest,followed by the upper leaf and the lower leaf;The total sensory scores of upper leaves in Xingwen County were significantly higher than those of the other three counties,the difference of the total sensory scores of middle leaves among the tobacco planting counties was not much,and the lower leaves in Xingwen County and Gong county were the best.6.Correlation analysis of chemical components of tobacco leaves with apparent quality and sensory smoking quality.Total sugar,reducing sugar,total nitrogen and nicotine had great influence on the appearance quality and sensory evaluation of tobacco leaves;Furfural,phenylacetaldehyde,benzaldehyde,5-methylfurfural β-Cyclocitral,furfuryl alcohol,benzyl alcohol,phenylethanol,famesyl acetone,megastigmatrienone a,megastigmatrienone D,3-hydroxy-β-Dihydrodamascone,isophorone,2-Acetylfuran,2-acetylpyrrole and neophytadiene were significantly correlated with the sensory evaluation quality of tobacco leaves;The results of canonical correlation analysis showed that:within a certain range,with the increase of reducing sugar,potassium,sugar alkali ratio,nitrogen alkali ratio,potassium chloride ratio,the scores of color and leaf structure of tobacco leaves would increase,while with the increase of chloride ion and the decrease of potassium chloride ratio,the scores of oil and chromaticity of tobacco leaves would increase;The results of canonical correlation analysis between chemical composition and sensory evaluation showed that:in a certain range,with the increase of the content of two sugars,potassium,starch,nitrogen alkali ratio,potassium chloride ratio,the temperament,irritation,fineness,roundness and dryness of tobacco leaves would increase,while with the decrease of nicotine content and the increase of chloride ion and sugar alkali ratio in tobacco leaves,The scores of aroma and aftertaste of tobacco leaves will increase;The typical correlation analysis of neutral aroma substances and sensory quality of tobacco leaves shows that in a certain range of furfural,2-acetylfuran,5-methylfurfural,2-acetyl pyrrole,benzyl alcohol,farnesyl acetone,megastrienone 1,megastrienone 2,3-hydroxy-β-dihydrodamascenone,new phytodiene and other aroma substances content increases,the aroma quality,aroma volume,Impurity,aftertaste,irritation,and softness scores will tend to increase.7.Analysis of main flue gas components of Yibin flue cured tobacco.Conventional chemical composition of mainstream flue gas:the average moisture content is 2.26-2.72 mg/branches,the average nicotine content is 1.42-1.86 mg/branches,the average total particulate matter content is 16.59-19.28 mg/branches,and the average tar content is 13.53-14.88 mg/branches.The transfer efficiency of different kinds of aroma substances in mainstream flue gas is different,and the content of aroma substance in tobacco leaves is positively correlated with the content of aroma substances in flue gas.