Beef Carcass Size and Aging Time Effects on Yield and Color Characteristics of Top Round Steaks

Abstract

Variation in cut size and weight of fabricated subprimals is a challenge of increased beef carcass weights. Subsequently, variation in carcass size has resulted in consistency challenges during retail display. The objective of this study was to assess three aging periods of commercially available top rounds from varying carcass weights as it relates to yield and color characteristics. In the current study, 21 industry average weight (AW; 340 to 409 kg; no industry discount) beef carcasses and 21 oversized (OS; exceeding 454 kg; receive a discount) beef carcasses were evaluated. Carcasses were selected at a commercial beef packing plant, where the left and right (paired) top round subprimals of each carcass were procured. Paired top rounds were assigned to a short (8 d), average (23 d), or extended (42 d) postmortem aging period. After wet-aging, subprimals were fabricated into steaks for additional analysis. Steaks were evaluated as whole top round steaks or further fabricated into “superficial” and “deep” portions at 5.08 cm from the superficial edge of the Semi-membranosus and the Adductor muscle. Top rounds and steaks from OS carcasses were larger (P < 0.01) than those from AW carcasses. Quantitative color of the anatomically deep locations of the OS steaks had the greatest mean L* (lightness; P < 0.01), a* (redness; P < 0.01) and b* (yellowness; P < 0.01) values. Extending the aging timeline increased L* (light-ness; P < 0.01), decreased a* (redness; P < 0.01), and decreased b* (yellowness; P < 0.01). Alternative top round steak fabrication that separates the deep and superficial anatomical locations could be an effective means of providing more uniform steaks.