Lancaster Jessica M, Buseman Brianna J, Weber Tanya M, Nasados James A, Richard Ron P, Murdoch Gordon K, Price William J, Colle Michael J, Bass Phillip D
Department of Animal and Veterinary Sciences, University of Idaho, Moscow, ID.
Statistical Programs, College of Agricultural and Life Sciences, University of Idaho, Moscow, ID.
Transl Anim Sci. 2020 Oct 30;4(4):txaa199. doi: 10.1093/tas/txaa199. eCollection 2020 Oct.
Beef carcass weights in the United States have continued to increase over the past 30 yr. As reported by the United States Department of Agriculture, grid-based carcass weight discounts begin when carcasses exceed 408 kg. Despite weight discounts, beef carcass weights continue to increase. At the same time, an increased prevalence of discoloration and color variability in top round subprimals has been observed throughout the industry which may be influenced by the increases in carcass weights. The objectives of this study were to assess the effects of beef carcass size and its relationship to chill time, color, pH, and tenderness of the beef top round. In the current study, eight industry average weight beef carcasses (AW, 341-397 kg) and eight oversized beef carcasses (OW, exceeding 432 kg) were evaluated. Temperatures and pH measurements were observed on both sides of all carcasses for the initial 48 h postharvest at a consistent superficial and deep anatomical location of the respective top rounds. Carcasses were fabricated into subprimals at 48 h and top rounds were aged at 2 °C for an additional 12 d. The superficial location of both AW and OW carcasses cooled at a faster rate ( < 0.01) than the deep locations. The deep location of OW carcasses had a lower pH and a more rapid ( < 0.01) initial pH decline. Quantitative color of steaks from OW carcasses had greater mean * (lightness; = 0.01) and initial * (yellowness; < 0.01) values. The delayed temperature decline and the accelerated pH decline of the deep location of the top round of OW carcasses occur at different rates than AW carcasses. Delayed rate of cooling leads to irreversible impacts on steak appearance of top round steaks fabricated from OW beef carcasses when compared with AW carcasses.
在过去30年里，美国牛肉胴体重量持续增加。美国农业部报告称，当胴体超过408千克时，基于网格的胴体重量折扣就会开始。尽管有重量折扣，但牛肉胴体重量仍在继续增加。与此同时，整个行业都观察到上腰部切块中变色和颜色变异性的发生率有所增加，这可能受到胴体重量增加的影响。本研究的目的是评估牛肉胴体大小的影响及其与牛肉上腰部的冷却时间、颜色、pH值和嫩度的关系。在本研究中，评估了8个行业平均重量的牛肉胴体（AW，341 - 397千克）和8个超大牛肉胴体（OW，超过432千克）。在收获后的最初48小时内，在各个上腰部一致的浅表和深部解剖位置对所有胴体的两侧进行温度和pH值测量。胴体在48小时时被分割成切块，上腰部在2℃下再熟成12天。AW和OW胴体的浅表位置冷却速度比深部位置更快（<0.01）。OW胴体的深部位置pH值较低，初始pH值下降更快（<0.01）。来自OW胴体的牛排的定量颜色具有更高的平均L*（亮度；P = 0.01）和初始b*（黄色度；P < 0.01）值。OW胴体上腰部深部位置温度下降延迟和pH值下降加速的速率与AW胴体不同。与AW胴体相比，冷却速度延迟对上腰部牛排外观产生不可逆影响，这些牛排由OW牛肉胴体制成。
