Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT 84322, USA.
Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523, USA.
J Anim Sci. 2022 Aug 1;100(8). doi: 10.1093/jas/skac042.
Tenderness is considered as one of the most important quality attributes dictating consumers' overall satisfaction and future purchasing decisions of fresh beef. However, the ability to predict and manage tenderness has proven very challenging due to the numerous factors that contribute to variation in end-product tenderness. Proteomic profiling allows for global examination of differentially abundant proteins in the meat and can provide new insight into biological mechanisms related to meat tenderness. Hence, the objective of this study was to examine proteomic profiles of beef longissimus lumborum (LL) steaks varying in tenderness, with the intention to identify potential biomarkers related to tenderness. For this purpose, beef LL muscle samples were collected from 99 carcasses at 0 and 384 h postmortem. Based on Warner-Bratzler shear force values at 384 h, 16 samples with the highest (intermediate tender, IT) and lowest (very tender, VT) values were selected to be used for proteomic analysis in this study (n = 8 per category). Using tandem mass tag-based proteomics, a total of 876 proteins were identified, of which 51 proteins were differentially abundant (P < 0.05) between the tenderness categories and aging periods. The differentially identified proteins encompassed a wide array of biological processes related to muscle contraction, calcium signaling, metabolism, extracellular matrix organization, chaperone, and apoptosis. A greater (P < 0.05) relative abundance of proteins associated with carbohydrate metabolism and apoptosis, and a lower (P < 0.05) relative abundance of proteins involved in muscle contraction was observed in the VT steaks after aging compared with the IT steaks, suggesting that more proteolysis occurred in the VT steaks. This may be explained by the greater (P < 0.05) abundance of chaperonin and calcium-binding proteins in the IT steaks, which could have limited the extent of postmortem proteolysis in these steaks. In addition, a greater (P < 0.05) abundance of connective tissue proteins was also observed in the IT steaks, which likely contributed to the difference in tenderness due to added background toughness. The established proteomic database obtained in this study may provide a reference for future research regarding potential protein biomarkers that are associated with meat tenderness.
嫩度被认为是决定消费者整体满意度和未来新鲜牛肉购买决策的最重要质量属性之一。然而，由于导致最终产品嫩度变化的因素众多，预测和管理嫩度的能力极具挑战性。蛋白质组学分析可以全面检查肉中差异丰富的蛋白质，并为与肉嫩度相关的生物学机制提供新的见解。因此，本研究的目的是研究嫩度不同的牛背最长肌（LL）牛排的蛋白质组谱，旨在确定与嫩度相关的潜在生物标志物。为此，从 99 个胴体中采集了 0 和 384 小时死后的牛 LL 肌肉样本。根据 384 小时的 Warner-Bratzler 剪切力值，选择 16 个具有最高（中等嫩度，IT）和最低（非常嫩，VT）值的样本用于本研究的蛋白质组分析（n = 8 个每个类别）。使用串联质量标签基蛋白质组学，共鉴定出 876 种蛋白质，其中 51 种蛋白质在嫩度类别和老化期间差异丰富（P < 0.05）。差异鉴定的蛋白质涵盖了与肌肉收缩、钙信号、代谢、细胞外基质组织、伴侣和细胞凋亡相关的广泛生物学过程。与 IT 牛排相比，老化后 VT 牛排中与碳水化合物代谢和细胞凋亡相关的蛋白质相对丰度较高（P < 0.05），而与肌肉收缩相关的蛋白质相对丰度较低（P < 0.05），这表明 VT 牛排中的蛋白质水解更多。这可能是由于 IT 牛排中伴侣蛋白和钙结合蛋白的丰度较高（P < 0.05），这可能限制了这些牛排的死后蛋白质水解程度。此外，在 IT 牛排中还观察到结缔组织蛋白的丰度较高（P < 0.05），这可能由于背景韧性增加导致嫩度差异。本研究中建立的蛋白质组数据库可为未来与肉嫩度相关的潜在蛋白质生物标志物研究提供参考。
