Does high voltage electrical stimulation of sheep affect rate of tenderisation?

Romney-cross sheep (n=24)were shot with a captive bolt, slaughtered, and dr essed and suspended by the Achilles tendons. Half of each group of carcasse s did not have any electrical input. The remaining carcasses were electrica lly stimulated at 30 min post mortem for 90 s using 1130 V peak (current 2 A) pulses (half sine wave, 10 ms duration) at an alternating pulse frequenc y of 14.28 pulses s(-1). All carcasses were placed into a room at 10 degree sC with an air velocity of 1-1.5 m s(-1). At rigor mortis (ultimate pH) the m. longissimus thoracis et lumborum was removed and cut into four portions to age for 0, 9, 30, and 57 hours at 10 degreesC then frozen at -20 degree sC, cooked from the frozen state, and 1 cm x 1 cm samples sheared using a M IRINZ tenderometer. The sarcomere length of small fibre bundles was measure d by laser diffraction and showed no difference between the treatment group s but became longer from rump to head. By chilling and ensuring both electr icity stimulated and non-stimulated muscle enters rigor mortis at temperatu res from 10 to 17 degreesC, and indexing the start of ageing to rigor morti s, the rate of tenderisation was the same. Stimulation therefore exerts its main effects through early rigor mortis and ageing at higher temperatures.