Research On Segmentation Curing Technology Of Tobacco Leaves

In order to explore new technology of tobacco curing, the experiment was taken middle leaves of NC55 as experimental material, compared with whole leaf curing, setting three curing treatments: removed the petiole of tobacco leaves, half leaves which removed the primary vein and segmentation curing. During the curing process, we were measured the differences of physiological and biochemical changes and the quality of flue-cured tobacco of different segmentation treatments. The experiment will provide a theoretical basis for improving the curing quality of tobacco leaves and promoting the curing technology. The main results are as follows:(1) Difference of the quality of fresh tobacco leaves in different segmentationThe quality of fresh tobacco leaves in different segmentation showed relatively large difference: the water content, chlorophyll content, carotenoid content, polyphenol oxidase(PPO) activity, peroxidase(POD) activity, total nitrogen content and protein content in leaf base section were the highest; amylase activity, reducing sugar and nicotine content in leaf tip section were the highest; The content of total sugar in whole leaf was the highest; but leaf mid section contains had more starch content than any other treatments. Therefore, the segmentation curing could be further optimized in future, after cutting tobacco leaf into leaf base, leaf mid and leaf tip, and then curing separately, realizing precision curing according to tobacco quality, improving the quality of flue-cured tobacco leaves.(2) The physiological indexes of different segmentation treatments during curing processThe chlorophyll degradation of leaf tip of segmentation curing、leaf mid of segmentation curing、curing without leaf base and chopping tobacco curing were relatively complete, PPO activity were lower and POD activity were higher, brown reaction were less likely to occur. During curing process, PPO activity of whole leaf curing and leaf base of half leaves which were cut into three sections curing were high, and amylase activity were low, so browning reaction were easily occurring and went against to starch degradation.(3) The impact of flue-cured tobacco yield and economic characters of different segmentation treatmentsThe yield of segmentation curing was lower than whole leaf curing and curing without leaf base, but dry leaves of the ratio of curing parts and total leaf were all larger than fresh leaves, so the contribution to yield of flu-cured leaves of primary vein was small. Moreover, segmentation curing could shorten the curing time, not only holding the aroma of leaves, but also reducing the energy consumption. To a certain extent, segmentation curing could improve the economic benefit of tobacco leaves. Economic characters of leaf tip of segmentation curing and leaf mid curing of segmentation curing were better than any other treatments and had little difference, curing without leaf base and chopping tobacco curing taken the second place, leaf base of segmentation curing and whole leaf curing were the worst. Therefore, segmentation curing could promote the average price of tobacco leaves, but had a certain influence to the yield of flu-cured tobacco leaves; the purchase price of segmentation curing leaves could be appropriately improved.(4) The impact of flue-cured tobacco quality of different segmentation treatmentsSmoking quality of leaf tip of segmentation curing and leaf mid of segmentation curing are better than curing without leaf base and chopping tobacco curing, but the chemical composition of curing without leaf base and chopping tobacco curing are more harmonious. Except to whole leaf curing and leaf base of segmentation curing, the qualities of flu-cured tobacco leaves of other segmentation treatments were better. But leaves without primary vein had more green mark, mainly because of the faster water loss rate during yellowing stage. It is recommended that properly improving the relative humidity of barn during yellowing stage could prevent moisture loss too fast, and the tobacco leaves could turn yellow thoroughly.