Analysis of Surface Color of Flue-cured Tobacco from Different Growing Areas by Spectroradiometer Measurements

Abstract

The surface color measurement and analysis of flue-cured tobacco,C3F, from 57 growing areas were carried out with a Color-Eye 7000A spectroradiometer and characterized with a L*a*b* uniform color space,and the variance analysis, cluster analysis,and correspondence analysis of measured data were conducted.The results showed that: 1) The surface color spatial distribution characters of C3F were L* 50-64,a* 13-19,b* 41-55 and C* 44-58.And the characteristic parameters differed extremely significantly between leaves from different growing areas.2) The C3F from different growing areas could be divided into four categories according to their surface color spatial distribution characters,Category Ⅰ was mainly centering in southeast tobacco growing areas;Category Ⅱ was mainly centering in Huanghuai and north tobacco growing areas;Category Ⅲ was mainly centering in Sichuan tobacco growing areas;Category Ⅳ was mainly centering in Yunnan,Guizhou,Chongqing and Hubei tobacco growing areas.Those categories basically agreed with the results of visual discrimination on leaf color.3) The leaf from the areas in Category Ⅰ and Category Ⅲ neighbored more to red-green chromaticity index a*,that from the areas in Category Ⅱ and Category Ⅳ neighbored more to brightness L*,that from the areas in Category Ⅲ and Category Ⅳ was adjacent more to yellow-blue chromaticity index b* and color saturation C*.The clustering results of surface color spatial distribution characters agreed with the correspondence between color characteristic parameters and tobacco growing areas.