Electrical currents applied to lamb carcasses — effects on blood release and meat quality

Abstract

The amount of collectable blood during the early phase of slaughter was determined for 48 lambs in 4 treatment groups: a control group (no current, no thoracic stick), a thoracic stick group only and groups subjected to a thoracic stick and either an electric current of 14 or 10 Hz frequency. The current was applied to the ‘skin-on’ carcass soon after the stunning/sticking process and subsequent to the thoracic stick, with a view to increasing the volume of blood released at that time. With both frequencies there was a small, but statistically significant (P<0.05), increase in the amount of released blood over non-stimulated treatments. Samples of M. longissimus thoracis et lumborum were aged for 1 and 5 days before freezing. Warner–Bratzler shear force measurements indicated the effectiveness of the current applications in reducing shear force with the 14 Hz waveform being superior to the 10 Hz waveform and in a related way the degradation of myofibrillar proteins was greater in meat subjected to the 14 Hz treatment when examined using the myofibrillar fragmentation index.