Quantitation of Surface Color of Flue-cured Tobacco Leaves and its Relationship with Carotenoid

In order to reveal the possible causes about the color difference among flue-cured tobacco leaves of different growing areas in China,the surface color of tobacco leaves,C3F,from 60 counties in 11 provinces were measured,analyzed and characterized with L^*a^*b^* uniform color space. The relationship between surface color spatial distribution characteristics of and carotenoid content in leaves was investigated. The results showed that: 1) The surface color spatial distribution indexes, L^* (brightness), a^* (red chroma), b^* (yellow chroma),c^* (color saturation),and carotenoid content were obviously different among leaves from different areas. The L^*,b^*,c^* and carotenoid content in tobacco leaves from the southeast tobacco belt were lower, while a^* and lutein proportion were higher; for tobacco leaves from the upper and middle reaches of the Yangtze River and the southwest tobacco belts,L^*,b^*,c^* and carotenoid content were higher,while a^* was relatively lower;L^* of tobacco leaves from the northern tobacco belt was relatively higher,while c^* and carotenoid content were relatively lower. 2)The carotenoid content in tobacco leaves closely correlated to leaf's surface color spatial distribution indexes. With the increase of carotenoid content,a^*,b^*,and c^* increased significantly,however the ratio of L^* to b^* decreased significantly.