Localized low voltage electrical stimulation improves meat quality and palatability in a muscle-dependent manner

The effect of localized low voltage electrical stimulation (LVES, 45 V) on meat quality and palatability of the longissimus thoracis et lumborum (LTL) and semitendinosus (ST) was evaluated in this study. There were stimulation method × ageing time interactions for pH in both muscles, as LVES reduced the pH at 3 h post-mortem, but there were no differences at 3 and 6 d post-mortem (P < 0.001). The LVES did not significantly affect colour values of the longissimus thoracis (LT) either at 3 d post-mortem (P > 0.05) or in retail display (P > 0.1). In contrast, there were stimulation × ageing time interactions in the ST for a^⁎, b^⁎ and chroma measured in retail display, with stimulation increasing all these values at 0 d, whereas there were no effects on a^⁎ and chroma and a lesser increase in b^⁎ after 4 d (P < 0.001). Additionally, the LVES increased L^⁎ (P < 0.05) and hue (P < 0.001) of the ST, regardless of retail time. The LVES increased purge losses of the ST (P < 0.05), although these moisture losses did not result in differences in ST juiciness assessed by trained panelists (P > 0.1). The LVES did not affect shear force or tenderness in any muscle (P > 0.1). Compared to no stimulation, LVES increased burnt aroma (P < 0.05) and umami (P < 0.01) and salty (P = 0.075) tastes and decreased bitter taste (P < 0.01) and green-hay flavour (P < 0.05) in the longissimus lumborum (LL), but had no effect on the flavour profile of the ST (P > 0.1). Overall, LVES improved meat colour and flavour in a muscle-dependent manner compared to no stimulation.