Effects Of Different Maturity Of Upper Leaves Of Flue-cured Tobacco On The Physiology And Biochemistry Of Cured Tobacco And The Quality Of Cured Tobacco Leaves

In order to explore the differences in the physiological and biochemical characteristics of upper leaves with different maturity and the quality of tobacco leaves after curing,Yunyan 87 was used as material to study the effects of different maturity on the physiological and biochemical characteristics of upper leaves during curing and the quality of tobacco leaves after curing,and the comprehensive evaluation was made by using principal component analysis.The results showed that:1.There are differences in physiological and biochemical characteristics of tobacco leaves with different maturity.1)Moisture and dry matter: with the improvement of maturity,the water loss rate of tobacco leaves accelerated,and the dry matter loss increased.2)Pigments: the degradation rate of chlorophyll gradually decreased with the increase of maturity,while the degradation rate of carotenoids first decreased and then increased.3)Enzyme activity: with the improvement of maturity,the activities of ?-amylase,T-SOD and POD increased first and then decreased,while the activity of PPO and the content of MDA increased gradually.4)Chemical composition: with the improvement of maturity,the contents of starch,total nitrogen,nicotine and protein decreased gradually,the contents of total sugar,reducing sugar,potassium and petroleum ether extract increased first and then decreased,and the total phenol content increased gradually.5)Correlation analysis showed that there was correlation between physiological and biochemical indexes.Principal component analysis showed that BM3 baking had the best physiological and biochemical characteristics,followed by BM4 and BM2,and BM1.2.The quality of roasted tobacco leaves changes regularly with the improvement of maturity.1)Appareance quality: color,maturity,identity,oil content,chroma and structure all showed a trend of increasing first and then decreasing;The average price,quality tobacco rate,orange tobacco rate and high ripening rate all showed a trend of increasing first and then decreasing,while the variegated tobacco rate firstly decreased and then increased.2)Chemical composition: the ratio of total nitrogen,nicotine,protein,starch,nitrogen and alkali showed a decreasing trend;the ratio of reducing sugar,total sugar,potassium,petroleum ether extract,sugar and alkali showed a rising trend and then a decreasing trend;the ratio of two sugars and Schmook value showed an increasing trend.3)Evaluation quality: aroma temperament,aroma quantity,taste,miscellaneous gas,stimulation,energy and total score showed a trend of increasing first and then decreasing.4)Correlation analysis showed that there was correlation between quality indexes of tobacco leaves after curing.Principal component analysis showed that BM3 was the best,BM2 and BM4 were the next,and BM1 was the worst.3.There is a correlation between the physiological and biochemical indexes during the curing process and the quality indexes of tobacco leaves after curing.The physiological and biochemical characteristics of curing can directly or indirectly affect the final quality of tobacco leaves.