Influence of Carcass Maturity and Marbling on the Physical and Chemical Characteristics of Beef. II. Muscle Pigments and Color

Abstract

Eighty wholesale beef ribs from carcasses of four U.S.D.A. maturity levels (A, B, C and D) and two marbling levels (moderate and slight) were studied. The longissiums dorsi muscle was used for all tests. The three components of color (Munsell hue, value and chroma) were measured by the use of a Photovolt Reflection Meter. Myoglobin and hemoglobin determinations were made by converting these pigments to carbon monoxide compounds. Total pigment values obtained by adding these two pigments were compared with total values resulting from the use of a cyanmet conversion method. The carbon monoxide pigment values were analyzed statistically on fresh, moisture-free and moisture- and fat-free bases. Myoglobin and hemoglobin, on all three bases of analysis, increased with advancing maturity, but only between the A and the other three maturity levels were the differences significant. Marbling alone had no effect on myoglobin or hemoglobin. Of the three Munsell color components, only value was affected significantly by maturity, while only hue was influenced by marbling. Value decreased significantly with increasing maturity, but the differences were significant only at the A maturity level. Hue increased significantly with increased marbling. Significant correlations existed between myoglobin content and Munsell values, but the correlations were not large enough to derive a reliable predictive equation. Hemoglobin was not correlated significantly with Munsell value. Hemoglobin was negatively correlated with flavor, indicating that higher hemoglobin content was associated with more desirable flavor.