Effect of type and time of electrical stimulation on drip loss and meat colour in beef striploin

The effects of type (high and low voltages) and time (3, 40 and 60 min postmortem) of stimulation on the rate of pH decline, drip loss and meat colour at 24 hours were determined on M. longissimus dorsi of 38 crossbred steers and heifers. Either high or low voltage stimulation at 3 min showed a tendency for faster pH decline (p = 0.052) and higher drip loss (p = 0.08), and improved the colour dimensions of L*, a* and b* (p < 0.01), compared to stimulation at 40 min. This was equivalent to approximately one unit of an AUS-MEAT colour chip. On the other hand, although there were significant differences in pH decline between high voltage stimulation at 40 and 60 min, and between low voltage stimulation at 40 min and control sides, drip loss and meat colour did not differ significantly (p > 0.05). The results suggested that early application of stimulation, regardless of type of stimulation, overall improved meat colour at 24 hours postmortem through its effect on faster glycolysing rate. However, if the pH decline was moderate, the benefit of electrical stimulation on meat colour was not apparent. The study implies that the beneficial or adverse effects of electrical stimulation on drip loss and meat colour is determined by the rate of pH decline, rather than stimulation treatment and time of application per se.