Effects of beef carcass size, and subsequent aging time, on yield and color characteristics of top round steaks

Abstract

Variation in cut size and weight of fabricated subprimals is a challengeof increased beef carcass weights. Subsequently, variation in carcass size hasresulted in consistency challenges during retail display. Theobjective of this study was to assess the retail shelf-life of commerciallyavailable top rounds from varying carcass weights. In the current study, 21industry average weight (AW, 340-409 kg; no industry discount) beef carcassesand 21 oversized (OS, exceeding 454 kg; receive a discount) beef carcasses wereevaluated. Carcasses were selected at a commercial beef packing plant, wherethe left and right (paired) top round subprimals of each carcass were procured.Paired top rounds were assigned to a short (8d), average (23d), or extended(42d) postmortem aging period. After wet-aging, subprimals were fabricated intosteaks for additional analysis. Steaks were evaluated as whole top round steaksor further fabricated into “superficial” and “deep” portions at 5.08 cm fromthe superficial edge of the Semimembranosus and the Adductor muscle.Top rounds and steaks from OS carcasses were larger (P < 0.01) thanthose from AW carcasses. Quantitative color of the anatomically deep locationsof the OS steaks had the greatest mean L* (lightness; P < 0.01), a*(redness; P < 0.01) and b* (yellowness; P < 0.01) values. Extendingthe aging timeline increased L* (lightness; P < 0.01), decreased a*(redness; P < 0.01), and decreased b* (yellowness; P <0.01). Alternative top round steak fabrication which separates the deep andsuperficial anatomical locations could be an effective means of providing moreuniform steaks.