Abstract:
In order to evaluate the suitability of chromatic aberration as a method to monitor tobacco leaf cutting, the B2F, C3F and X2F cured K326 tobacco leaves were selected as test samples. After removing the petiole, a tobacco leaf was longitudinally divided into 10 locations at equal length. The lightness value (
L*), redness value (
a*), yellowness value (
b*) at each location were determined by a colorimeter. Regression analysis was used to study the variations of chromatic aberration values at different locations of K326.Appropriate sectioning proportion and sensory quality of tobacco leaves from different stalk positions were analyzed by Fisher's optimal segmentation method and sensory evaluation respectively. The results showed that: 1) For the upper, middle, lower leaves of cured K326, from the base to the tip, the
L* value presented a decreasing parabolic trend, and the values of
a*,
b* and △
E (total chromatic aberration) presented an increasing parabolic trend first and then a decreasing one. 2) On the basis of the standardized chromatic aberration matrix, the optimal sectioning proportions for cured K326 were determined by Fisher optimal segmentation method as:20%:50%:30% for B2F (base:middle:tip); 30%:50%:20% for C3F (base:middle:tip), and 10%:30%:40%:20% for X2F (base:near base:middle:tip), respectively. 3) The results of three-point test indicated that the overall sensory quality differed significantly at the different locations. It was suggested that the chromatic aberration combined with Fisher optimal segmentation could effectively separate the locations with greatest sensory quality difference of the same leaf.