Effect of background color, sample thickness, and illuminant on the measurement of broiler meat color.

The effects of sample thickness (0.5, 1.0, and 1.5 cm), background color (white, pink, green, and gray), and illuminant (D-65, A, and F) on color measurement of broiler tissue were determined. Color values from the anterior portions of the two Pectoralis superficialis muscles were not different from each other, allowing one to be used as a control for the other. Light penetrated the thinner posterior portions of the muscle and was reflected by the white background, producing different L*, a*, and b* values when compared to the thicker anterior portion of the muscle. These changes could alter or mask color changes in the tissue. Light penetrated 0.5 cm thick sliced breast, ground breast, and ground thigh samples and was reflected by the background in large enough quantities to cause color differences (P < 0.05) when both sample thickness and background colors were compared. White and pink backgrounds reflected the largest amount of light, followed in decreasing order by green and gray. The light reflected by background decreased as sample thickness increased from 0.5 to 1.0 cm and no differences due to reflection occurred in the 1.5 cm thick samples. Background reflection can prevent measurement of true sample color. The three illuminants produced different (P < 0.05) color values depending on the major wavelength characteristics of each illuminant. Illuminant choice should depend on wavelength characteristics of the illuminant, sample color, and the color values to be measured.