Department of Animal Science, Division of Agriculture, University of Arkansas, Fayetteville, Arkansas 72701, USA.
J Anim Sci. 2011 Dec;89(12):4207-20. doi: 10.2527/jas.2011-4147. Epub 2011 Aug 19.
Two experiments were conducted to compare the effects of enhancing dark-cutting (DC) strip loins with lactic acid (LAC) on fresh and cooked beef color, as well as sensory attributes, with nonenhanced, normal pH strip loins (CH). Strip loins, with an average ultimate pH of 6.70 ± 0.11 (Exp. 1) and 6.78 ± 0.11 (Exp. 2), were cut into 2 equal-length sections, and DC sections were randomly assigned as either nonenhanced DC or DC enhanced with 0.15 (Exp. 1), 0.35 (Exp. 1 and 2), or 0.50% (Exp. 2) LAC at a target of either 105 (Exp. 1) or 112% (Exp. 2) of the raw product weight. Enhancement with 0.15 and 0.35% LAC did not (P > 0.05) affect postenhancement pH of DC strip loins when enhanced at a target of 105% (Exp. 1); however, postenhancement pH was reduced (P < 0.05) substantially by LAC enhancement at 115% of raw product weight, with pH values of DC sections enhanced with 0.50% LAC being similar (P > 0.05) to those of CH strip loin sections (Exp. 2). In Exp. 1, raw steaks from CH strip loins had greater (P < 0.05) a* and b* values as well as Japanese beef color scores compared with steaks from nonenhanced and LAC-enhanced DC strip loins across the first 3 d of simulated retail display (LAC enhancement × retail display duration; P < 0.01). Again in Exp. 2, raw steaks from CH sections had greater (P < 0.05) L*, a*, and b* values and Japanese color scores than did steaks from DC sections, regardless of LAC enhancement; however, mean Japanese color scores of CH steaks were only 0.7 and 0.4 units greater (P < 0.05) than the color scores of DC steaks enhanced with 0.35 and 0.50% LAC, respectively. In Exp. 1, CH steaks received the highest (P < 0.05) cooked color and degree of doneness scores, yet scores for CH steaks and steaks from DC sections enhanced with 0.50% LAC did not (P > 0.05) differ when cooked to 71°C in Exp. 2. Fresh and cooked color of DC beef was only minimally altered when enhanced with 0.35% LAC at 105% of the fresh product weight; however, when DC beef was enhanced with 0.35 and 0.50% LAC at a target of 112%, fresh and cooked color were improved close to that of CH beef. Because the persistent red or pink cooked color of DC was virtually eliminated by 0.50% LAC enhancement, LAC-enhanced DC beef may be suitable for food-service markets; however, the raw or fresh color results of Exp. 2 suggested that the fresh color of DC beef can be improved to the color of normal pH beef by postmortem acidification, leading to the possible recoupment of most, if not all, of the lost value associated with DC beef.
进行了两项实验来比较在黑暗切割（DC）带里脊中添加乳酸（LAC）对新鲜和煮熟牛肉颜色的影响，以及与未经增强的正常 pH 值带里脊（CH）相比，感官属性。带里脊的最终 pH 值平均为 6.70 ± 0.11（实验 1）和 6.78 ± 0.11（实验 2），切成两段相等长度的部分，将 DC 部分随机分配为未经增强的 DC 或在目标为 105%（实验 1）或 112%（实验 2）原始产品重量的 0.15%（实验 1）、0.35%（实验 1 和 2）或 0.50%（实验 2）的 LAC 增强。当以 105%的目标增强时，0.15%和 0.35%的 LAC 增强不会（P>0.05）影响 DC 带里脊的增强后 pH 值（实验 1）；然而，当以 115%的原始产品重量增强时，LAC 增强会大大降低（P<0.05）增强后 pH 值，增强后 pH 值与 CH 带里脊部分的 pH 值相似（P>0.05）（实验 2）。在实验 1 中，与未经增强和 LAC 增强的 DC 带里脊牛排相比，CH 带里脊的生牛排具有更高的（P<0.05）a和 b值以及日本牛肉颜色评分，在模拟零售展示的前 3 天（LAC 增强×零售展示持续时间；P<0.01）。同样在实验 2 中，与 DC 部分的牛排相比，CH 部分的生牛排具有更高的（P<0.05）L*、a和 b值和日本颜色评分，无论是否增强 LAC；然而，CH 牛排的平均日本颜色评分仅比用 0.35%和 0.50%的 LAC 增强的 DC 牛排的颜色评分高 0.7 和 0.4 个单位（P<0.05）。在实验 1 中，CH 牛排获得了最高的（P<0.05）煮熟颜色和熟度评分，但在实验 2 中，当煮至 71°C 时，CH 牛排和用 0.50%的 LAC 增强的 DC 牛排之间的评分没有（P>0.05）差异。当以 105%的新鲜产品重量用 0.35%的 LAC 增强时，DC 牛肉的新鲜和煮熟颜色仅略有改变；然而，当 DC 牛肉用 0.35%和 0.50%的 LAC 增强到 112%的目标时，新鲜和煮熟的颜色接近 CH 牛肉的颜色。由于 0.50%的 LAC 增强几乎消除了 DC 牛肉持久的红色或粉红色煮熟颜色，因此 LAC 增强的 DC 牛肉可能适合餐饮服务市场；然而，实验 2 的生色和新鲜色结果表明，通过死后酸化可以改善 DC 牛肉的新鲜色至正常 pH 值牛肉的颜色，从而可能挽回与 DC 牛肉相关的大部分（如果不是全部）损失价值。
