Effects of four types of light sources irradiation on the color and key chemical composition of tobacco leaves

WANG Jun; JIANG Jian; ZHAO Liang; XU Jian; HU Anfu; JIN Yixiao; DING Ning; CAI Ming

doi:10.12187/2025.05.009

Abstract：To optimize the light-regulation technology for tobacco leaf curing,four types of light sources(ultraviolet,infrared,red,and white light)were used to comparatively analyze key indicators such as color,polyphenolic substances,and volatile components during the fresh,yellowing,browning,and dry-gluten stages of curing for tobacco leaves from the upper,middle,and lower positions.This study explored the effects of different light-source irradiation on the color and key chemical components of tobacco leaves.The results showed that after white light treatment,the color of middle-position tobacco leaves was brighter,while after infrared light treatment,the color of upper-position tobacco leaves became darker.The total content of polyphenolic substances in upper-position tobacco leaves after infrared light treatment was higher than the total content of polyphenolic substances in other groups.The lower-position tobacco leaves had the highest content of volatile components.The key substances causing differences in volatile components among the four light-source groups for each position were nicotine and neophytadiene.Ultraviolet light treatment increased the aldehydes content in tobacco leaves,infrared light treatment increased the esters content,and white light and red light treatments increased the alcohols content.Among them,the characteristic substances pentanal,ethyl benzoate,and phenethyl alcohol increased significantly.Therefore,the four types of light-source treatments have different degrees of influence on the color and key chemical components of tobacco leaves,providing a reference for regulating tobacco leaf quality based on light technology.