In this study, the effect of pulsed electric field (PEF) treatment and ageing on the quality of beef M. longissimus
lumborum (LL) and M. semimembranosus (SM) muscles was evaluated, including the tenderness, water loss
and post-mortem proteolysis. Muscles were obtained from 12 steers (6 steers for each muscle), removed from
the carcasses 4 hour postmortemand were treatedwith pulsed electric fieldwithin 2 h. Six different pulsed electric
field intensities (voltages of 5 and 10 kV× frequencies of 20, 50 and 90Hz) plus a controlwere applied to each
muscle to determine the optimumtreatment conditions. Beef LL was found to get tougherwith increasing treatment
frequencywhereas beef SM musclewas found to have up to 21.6% reduction in the shear forcewith pulsed
electric field treatment. Post-mortemproteolysis showed an increase in both troponin and desmin degradation in
beef LL treated with low intensity PEF treatment (20 Hz) compared to non-treated control samples.