O'Sullivan Lydia M, Newton Clay J, Underwood Keith R, Grubbs Judson K, Bakker Christina E, Dinh Thu, Kruse Carter, Blair Amanda D
Department of Animal Science, South Dakota State University, Brookings, SD 57007, USA.
Tyson Foods, Springdale, AR 72762, USA.
Transl Anim Sci. 2025 Mar 12;9:txaf032. doi: 10.1093/tas/txaf032. eCollection 2025.
The objective of this study was to characterize the influence of finishing system on the sensory characteristics and mechanisms of tenderness formation in the (striploin) of bison bulls. Bison bulls (n = 196) were randomly assigned to one of two finishing treatments at approximately 25 mo of age: 1) Grain-finished (n = 98; placed in an open lot with ad libitum access to prairie hay, alfalfa hay, and whole shell corn prior to slaughter) or 2) Grass-finished (n = 98; bulls allowed to graze native pasture until slaughter). Bulls were harvested at approximately 30 mo of age and striploins were collected. Ultimate pH was recorded, and striploins were fabricated into steaks for assessment of sensory characteristics by consumer and trained sensory panels (steaks aged 14 d), and analysis of Warner-Bratzler shear force (WBSF; steaks aged 4, 7, 14 or 21 d). Additional steaks were aged for 14 d for determination of collagen content and sarcomere length. Proteolysis of desmin and troponin-T was evaluated on samples aged for 4, 7, 14, or 21 d. Consumer panel results indicate that grain-finished steaks had higher ratings for overall liking ( = 0.04) and flavor liking ( < 0.01) whereas off-flavor intensity was increased (< 0.01) for grass-finished steaks compared to grain-finished steaks. Trained panelists indicated that grass-finished bison steaks had increased (< 0.01) aroma and flavor intensities compared to grain-finished bison steaks and "ammonia, metallic, and gamey flavors" were associated with the grass-finished treatment. Warner-Bratzler shear force was affected by the interaction of finishing treatment with aging period (< 0.01). Steaks from the grain-finished bulls became more tender (0.02) as aging time increased from 4 d to 14 d, whereas WBSF of steaks from grass-finished bulls did not differ (≥ 0.10) during this period. Steaks from grass-finished bulls were more tender (0.01) than steaks from grain-finished bulls at 4 d and 7 d but treatments were similar (≥ 0.61) at 14 and 21 d. Samples from grass-finished bulls had less (< 0.01) intact desmin compared to grain-finished bulls. This study demonstrates that finishing system influences sensory attributes of steaks from bison bulls and highlights the role of proteolysis as the primary mechanism regulating tenderization of bison.
本研究的目的是确定育肥方式对野牛公牛里脊感官特性及嫩度形成机制的影响。196头野牛公牛在约25月龄时被随机分配到两种育肥处理之一：1）谷物育肥（n = 98；屠宰前置于露天场地，可自由采食草原干草、苜蓿干草和带壳玉米）或2）牧草育肥（n = 98；公牛在天然牧场放牧至屠宰）。公牛在约30月龄时屠宰并采集里脊。记录最终pH值，将里脊制成牛排，由消费者和专业感官评价小组评估感官特性（牛排陈化14天），并分析沃纳-布拉茨勒剪切力（WBSF；牛排分别陈化4、7、14或21天）。另外的牛排陈化14天以测定胶原蛋白含量和肌节长度。对陈化4、7、14或21天的样品进行结蛋白和肌钙蛋白-T的蛋白水解评估。消费者评价小组结果表明，谷物育肥的牛排总体喜好度评分更高（P = 0.04），风味喜好度评分更高（P < 0.01），而与谷物育肥牛排相比，牧草育肥牛排的异味强度增加（P < 0.01）。专业评价小组成员指出，与谷物育肥的野牛牛排相比，牧草育肥的野牛牛排香气和风味强度增加（P < 0.01），且“氨味、金属味和野味”与牧草育肥处理有关。沃纳-布拉茨勒剪切力受育肥处理与陈化时间的交互作用影响（P < 0.01）。随着陈化时间从4天增加到14天，谷物育肥公牛的牛排变得更嫩（P = 0.02），而在此期间牧草育肥公牛的牛排WBSF没有差异（P≥0.10）。在4天和7天时，牧草育肥公牛的牛排比谷物育肥公牛的牛排更嫩（P = 0.01），但在14天和21天时处理相似（P≥0.61）。与谷物育肥公牛相比，牧草育肥公牛的样品中完整结蛋白更少（P < 0.01）。本研究表明，育肥方式影响野牛公牛牛排的感官属性，并突出了蛋白水解作为调节野牛嫩化的主要机制的作用。
