Colour rating and pigment composition of beef: Relation between colour measurement by reflectance spectrophotometry, subjective colour evaluation, and the relative concentration of oxymyoglobin and ferric myoglobin in chilled retail‐packed beef

Abstract
Summary: Reflectance measurements and subjective colour evaluations of retail‐packed beef were recorded and compared. Subjective colour evaluation, which was found to be closely linked to the visual assessment of the overall quality of the meat, is largely determined by the percentage of oxymyoglobin (red) relative to ferric myoglobin (brown). The reflectance colour value, which is the difference in reflectances (expressed in absorbance units) at 580 and 630 nm, is linearly related to the percentage of oxymyoglobin and to the subjective colour score. The correlation between objective and subjective colour evaluation is statistically highly significant (correlation coefficient = 0.94).Reflectance spectrophotometry is thus shown to be a convenient and reliable method for objective colour measurement and for the determination of the pigment composition in the surface zone of intact beef samples.