Relationship between instrumental and visual color in a raw, fresh beef and chicken model system

A range of meat redness was created by mixing fresh, chilled ground chicken breast and ground beef in predetermined ratios. Samples were scored for vi sual redness under halogen (incandescent) and cool white fluorescent lighti ng. Instrumental color characteristics (L*, a*, b*, hue angle, chroma, illu minants A and F) and red color contributed by oxymyoglobin (percentage refl ectance at 630 nm versus 580 nm) were determined. Correlation coefficients were determined between visual and instrumental evaluations. The a*, b*, an d Delta R (630-580) were highly correlated to visual redness (halogen light : r = 0.99, -0.99, and 0.96 respectively; cool white fluorescent light: 0.9 8 -0.98, and 0.96 respectively). Regression analysis was conducted to devel op equations to predict visual redness using instrumental color measures. I n the 20% to 85% beef range, the regression curves were principally linear although the overall relationships (0-100% beef range) were cubic. Among th e instrumental color parameters, a*, hue angle, and Delta R (630-580) could be used to predict visual redness for this model system.