Department of Animal Sciences and Industry, Kansas State University, Manhattan, KS 66506.
J Anim Sci. 2019 Feb 1;97(2):669-686. doi: 10.1093/jas/sky435.
The objectives of this study were to evaluate the extent marbling compensates for reduced beef palatability at elevated degrees of doneness and to determine the relationship of residual moisture and fat in cooked steaks to beef palatability, specifically beef juiciness. Paired strip loins (IMPS # 180) were collected to equally represent five quality treatments [Prime, Top Choice (modest and moderate marbling), Low Choice, Select, and Select Enhanced (110% of raw weight)]. Steaks were grouped into sets of three consecutively cut steaks and randomly assigned a degree of doneness (DOD): very-rare (VR; 55 °C), rare (R; 60 °C), medium-rare (MR; 63 °C), medium (M; 71 °C), well done (WD; 77 °C), or very well done (VWD; 82 °C). Samples were subjected to consumer and trained sensory evaluation, Warner-Braztler shear force (WBSF), slice shear force (SSF), pressed juice percentage (PJP) evaluation, and raw and cooked proximate analysis. There were no (P > 0.05) quality treatment × DOD interactions for consumer sensory ratings, indicating increased DOD had the same negative impact regardless of marbling level. There was a quality treatment × DOD interaction (P < 0.05) for the percentage of steaks rated acceptable by consumers for juiciness. Increased marbling modified the point in which steaks became unacceptable for juiciness. Similarly, there was a quality treatment × DOD interaction (P < 0.05) for trained juiciness ratings. When cooked to MR and lower, Prime was rated only 8% to 18% higher (P < 0.05) than Select for trained juiciness ratings, but was rated 38% to 123% higher (P < 0.05) than Select when cooked to M and higher. Besides cooking loss, combined cooked moisture and fat percentage was more highly associated (P < 0.01) to consumer juiciness (r = 0.69) and trained initial (r = 0.84) and sustained (r = 0.85) juiciness ratings than all other objective evaluations. Using regression analyses, cooked moisture and fat percentages, alone, were poor indicators of consumer and trained juiciness ratings. However, when combined, the regression equations explained 45%, 74%, and 69% of the variation in consumer, trained initial, and trained sustained juiciness ratings, respectively. These results indicate that increased marbling levels only offer "insurance" for juiciness of steaks that are cooked to high degrees of doneness, but not for other palatability traits. Additionally, cooked residual moisture and fat percentages, when combined, are a good indicator of sensory juiciness ratings.
本研究的目的是评估大理石花纹在提高熟度水平时对牛肉适口性的补偿程度，并确定煮熟牛排中的残余水分和脂肪与牛肉适口性（特别是牛肉多汁性）的关系。采集配对的带骨里脊（IMPS # 180），以均匀代表五个质量处理[Prime、Top Choice（适度和适度大理石花纹）、Low Choice、Select 和 Select enhanced（原始重量的 110%）]。将牛排分为三组连续切割的牛排，并随机分配熟度（DOD）：非常罕见（VR；55°C）、罕见（R；60°C）、中等罕见（MR；63°C）、中等（M；71°C）、煮熟（WD；77°C）或非常煮熟（VWD；82°C）。对样品进行消费者和经过培训的感官评估、 Warner-Braztler 剪切力（WBSF）、切片剪切力（SSF）、压榨汁百分比（PJP）评估以及生肉和熟肉的近似分析。在消费者感官评分方面，质量处理×DOD 不存在交互作用（P > 0.05），这表明无论大理石花纹水平如何，DOD 升高都会产生相同的负面影响。在消费者可接受性评分方面，质量处理×DOD 存在交互作用（P < 0.05）。大理石花纹的增加改变了牛排变得不可口的临界点。同样，在经过培训的多汁性评分方面，存在质量处理×DOD 交互作用（P < 0.05）。当煮到 MR 及以下时，Prime 的多汁性评分仅比 Select 高 8%至 18%（P < 0.05），但当煮到 M 及以上时，Prime 的多汁性评分比 Select 高 38%至 123%（P < 0.05）。除了烹饪损失外，结合煮熟的水分和脂肪百分比与消费者多汁性（r = 0.69）和经过培训的初始（r = 0.84）和持续（r = 0.85）多汁性评分更密切相关（P < 0.01），与所有其他客观评估相比。使用回归分析，单独的煮熟水分和脂肪百分比是消费者和经过培训的多汁性评分的不良指标。然而，当结合使用时，回归方程分别解释了消费者、经过培训的初始和持续多汁性评分变化的 45%、74%和 69%。这些结果表明，大理石花纹水平的增加仅为高熟度牛排的多汁性提供“保险”，但不能为其他口感特征提供“保险”。此外，煮熟的残余水分和脂肪百分比结合使用是感官多汁性评分的良好指标。
