Meisinger J L, James J M, Calkins C R
Department of Animal Science, University of Nebraska, Lincoln, Nebraska 68583-0908, USA.
J Anim Sci. 2006 Oct;84(10):2826-33. doi: 10.2527/jas.2006-028.
This research compared off-flavor notes and the relationship of pH and heme-iron content to off-flavor for different beef muscles. After grading, knuckles and shoulder clods were removed from 16 USDA Choice and 14 USDA Select beef carcasses, vacuum-packaged, and aged for 7 d. The rectus femoris (REC), vastus medalis (VAM), vastus lateralis (VAL), teres major (TER), infraspinatus (INF), and triceps brachii-long head (TRI) were separated, cut into steaks, and frozen (-16 degrees C). Sensory analysis was conducted using a trained taste panel, with steaks grilled to an internal temperature of 65 degrees C. Heme-iron concentration and pH were determined. The INF had lower (P < 0.05) off-flavor intensity ratings and less frequent sour flavor than the other muscles, and the VAL had the most intense (P < 0.05) off-flavor ratings and among the greatest frequency of sour, charred, and oxidized flavors. The frequencies of liver-like, bloody, and rancid flavors were not affected by muscle type. Heme-iron concentration did not differ among muscles. Three USDA Select carcasses had intense off-flavor in the muscles. Liver-like flavor was highly negatively correlated with off-flavor intensity for each of the muscles tested. Muscles rated a 5 or below (on an 8-point rating scale, where 1 = extremely intense off-flavor and 8 = no off-flavor) in off-flavor intensity and identified as liver-like by 30% or more of the panelists were grouped together and compared to normal muscles. Those in the liver-flavored group were less frequently identified as charred, probably because the liver-like flavor was so intense. There were no differences between the 2 groups for sour, metallic, bloody, oxidized, or fatty off-flavor notes. Regression equations containing the linear and quadratic functions of heme-iron concentration, muscle pH, and their interaction were established for the frequency of off-flavor notes within each muscle. The REC, TER, VAL, and VAM showed a relationship between pH, heme iron, and off-flavor intensity (P < 0.05). Liver-like flavor was explained partially by pH and heme iron in the REC, VAM, and VAL (R2 = 0.45 to 0.55; P < 0.05). Few other significant relationships were found. Heme iron and pH were unrelated to metallic, oxidized, or rancid flavors for any of the muscles tested. These data suggest that liver-like off-flavors are specific to individual animals, and that pH and heme iron are not strongly related to off-flavor notes.
本研究比较了不同牛肉肌肉的异味特征以及pH值和血红素铁含量与异味之间的关系。分级后，从16头美国农业部精选级和14头美国农业部标准级牛肉胴体上取下指关节和肩肉，真空包装，并陈化7天。分离出股直肌（REC）、股内侧肌（VAM）、股外侧肌（VAL）、大圆肌（TER）、冈下肌（INF）和肱三头肌长头（TRI），切成牛排并冷冻（-16℃）。使用经过训练的味觉小组进行感官分析，将牛排烤至内部温度65℃。测定血红素铁浓度和pH值。与其他肌肉相比，INF的异味强度评分较低（P<0.05），酸味出现频率较低，而VAL的异味评分最高（P<0.05），酸味、烧焦味和氧化味出现频率最高。肌肉类型对类似肝脏味、血腥味和酸败味的频率没有影响。各肌肉间血红素铁浓度无差异。三头美国农业部标准级胴体的肌肉有强烈异味。在所测试的每块肌肉中，类似肝脏味与异味强度呈高度负相关。异味强度评分为5分及以下（8分制，1分=异味极强，8分=无异味）且被至少30%的小组成员鉴定为类似肝脏味的肌肉归为一组，并与正常肌肉进行比较。肝脏味组的肌肉被鉴定为烧焦味的频率较低，可能是因为类似肝脏味过于强烈。两组在酸味、金属味、血腥味、氧化味或脂肪味异味特征方面没有差异。针对每块肌肉中异味特征的频率建立了包含血红素铁浓度、肌肉pH值及其相互作用的线性和二次函数的回归方程。REC、TER、VAL和VAM的pH值、血红素铁与异味强度之间存在关联（P<0.05）。在REC、VAM和VAL中，类似肝脏味部分由pH值和血红素铁解释（R2=0.45至0.55；P<0.05）。未发现其他显著关系。对于所测试的任何肌肉，血红素铁和pH值与金属味、氧化味或酸败味无关。这些数据表明，类似肝脏味的异味是个别动物特有的，并且pH值和血红素铁与异味特征没有强烈关联。
