Image Fusion System for Non-Destructive Colour Evaluation of Papaya During Drying
Patchimaporn Udomkun1, Marcus Nagle1, Dimitrios Argyropoulos1, Busarakorn Mahayothee2, Joachim Müller1
1University of Hohenheim, Inst. of Agricultural Engineering, Tropics and Subtropics Group, Germany
Colour changes are common physical phenomenon observed during drying which need to be controlled, as it directly affects consumer acceptance of the dried products. This study aimed to investigate the effects of drying temperatures (50, 60, 70, 80 °C) on colour kinetics of papaya during drying. In addition, it monitored the feasibility of a computer vision system (CVS) combined with laser light backscattering analysis at 650 nm for predicting colour changes. The results showed that the lightness (L*) and redness (a*) values decreased, whereas yellowness (b*), hue (h*), chroma (C*) and total colour difference (ΔE) values increased as drying proceeded. The zero-order kinetic model was found to generate the great fit for L*, a* and $\Delta$E values, whereas b*, h* and C* values were adequately explained by the fractional conversion model. The activation energy (Ea) was manifested that the h* value was more sensitive to temperature than other parameters.
Keywords: Colour, drying, image analysis, laser backscattering, papaya
Contact Address: Patchimaporn Udomkun, University of Hohenheim, Inst. of Agricultural Engineering, Tropics and Subtropics Group, Garbenstrasse 9, 70599 Stuttgart, Germany, e-mail: Patchimaporn.Udomkununi-hohenheim.de