Abstract: Two different methods of colorimeter and computer vision system (CVS) were used for the detection of color changes in catfish (Clarias leather) muscle during ice storage for 18 days, and the accuracy of CVS in the measurement of fish muscle color (L*, a*, b*) was investigated. The experimental results illustrated that the changing trends of color and total color difference (ΔE) of catfish muscle during ice storage detected by both methods were similar. The lightness (L*) and ΔE values gradually increased with storage time (P < 0.05), redness (a*) increased slowly in the first 3 days, and then declined significantly (P < 0.05), and yellowness (b* value) did not significantly change during the whole storage period (P > 0.05). The CVS measured results were calibrated and validated with those measured by colorimeter. It was found that the calibration values were not significantly different from the results from colorimeter (P > 0.05). The correlation coefficients between the L*, a* and b* values from the two methods were from 0.89 to 0.97, suggesting that after calibration, the CVS values could describe the color changes in catfish muscle accurately, and allow rapid and accurate color measurement.

Key words: computer vision system, colorimeter, catfish, color, ice storage