Abstract：
This study examined the effects of constant current electrical stimulation (CCES) compared to constant voltage electrical stimulation (CVES), when applied within the same beef carcass (n = 79), on longissimus thoracis et lumborum (LTL) quality and palatability. There was a stimulation method × time interaction for pH, with CCES reducing the 3 h post-mortem pH, but increasing the 72 h post-mortem pH compared to CVES (P < 0.001). The CCES decreased the meat subjective Japanese Meat Grading Agency (JMGA) colour scores (P < 0.05) and increased the objective L⁎ (P < 0.01), a⁎ (P < 0.05) and b⁎ (P < 0.05) colour values at 3 d post-mortem and L⁎ and b⁎ values (P < 0.05) during retail display compared to CVES, although the objective values from both stimulation methods were above established consumer acceptability thresholds. Additionally, CCES reduced the purge (P < 0.05) and drip (P < 0.01) losses, and tended to reduce shear force values (P = 0.089) compared to CVES, although these did not translate into differences in juiciness or tenderness evaluated by trained panelists (P > 0.1). Regarding flavour, the CCES meat had greater bloody/serumy flavour (P < 0.05) and corn aroma (P < 0.05), less unidentified aroma (P < 0.05), and tended to have greater corn flavour (P = 0.077) and less barnyard aroma (P = 0.079) than CVES meat. There were also increased concentrations of flavour-related volatile compounds including 2-methyl-butanal, 3-methyl-butanal and 2-5-dimethyl pyrazine levels (P < 0.05) with CCES. Overall, the CCES system slightly improved meat quality and flavour compared to CVES when applied to the same beef carcasses. Further consumer studies would be warranted to determine whether these differences translate into more acceptable meat.
摘要：
这项研究检查了恒定电流电刺激（CCES）与恒定电压电刺激（CVES）相比的影响，当应用于同一牛肉尸体(n=79)时，胸腰长(LTL)质量和适口性。pH值存在刺激方法×时间相互作用，CCES降低了3小时的死后pH值，但与CVES相比，死后72小时的pH值增加(P<0.001)。CCES降低了肉类主观日本肉类分级机构（JMGA）颜色评分（P<0.05），增加了客观L（P<0.01），a(P<0.05)和b(P<0.05)在3d验尸时的颜色值以及与CVES相比的零售展示期间的L和b值(P<0.05),尽管两种刺激方法的目标值均高于既定的消费者可接受性阈值。此外,CCES减少了吹扫(P<0.05)和滴注(P<0.01)损失，与CVES相比，剪切力值趋于降低(P=0.089)，尽管这些没有转化为经过训练的小组成员评估的多汁性或压痛差异(P>0.1)。关于风味，CCES肉具有更大的血性/血清风味（P<0.05）和玉米香气（P<0.05），未识别的香气较少（P<0.05），与CVES肉相比，玉米风味更大（P=0.077）和谷仓香气更少（P=0.079）。与风味相关的挥发性化合物的浓度也增加，包括2-甲基丁醛，3-甲基-丁醛和2-5-二甲基吡嗪水平(P<0.05)与CCES。总的来说,当应用于相同的牛肉屠体时，与CVES相比，CCES系统略微改善了肉的质量和风味。需要进一步的消费者研究来确定这些差异是否转化为更可接受的肉类。
