Abstract
In this study, the effects of fibre direction and initial pH on the effectiveness of pulsed electric field (PEF) treatment (10 kV, 90 Hz, 20 mu s) to improve the quality of beef Longissimus muscle (LL) was evaluated. The traits studied included tenderness (shear force), water loss, meat colour, lipid oxidation and post-mortem proteolysis. Beef LL muscles of three different pH ranges (5.5-5.8, 5.8-6.1 and > 6.1) were obtained from 16 bull carcasses. The LL muscles were removed from the carcasses 24 h post-mortem and treated with pulsed electric field within 6 h. No significant effect was found on total water loss, shear force, meat colour and lipid stability between the treated and the corresponding non-treated control samples due to fibre direction or initial pH. Increased proteolysis was found in treated samples as evident by increases in troponin-T and desmin degradation. A larger increase in proteolysis was observed in low-pH (5.5-5.8) samples compared to the high-pH (> 6.1) samples which was reflected in shear force measurements.