Electrical stimulation of pigs - effect on pH fall, meat quality and Cathepsin B+L activity

This work was performed to evaluate the effect of electrical stimulation (E S) on pH fall and meat quality of LD and BF in Danish halothane free pigs s tunned with CO2. ES resulted in a significant drop in pH of 0.3 units in bo th LD and BF and 3 h lairage resulted in 0.1 units lower pH at 20 min post mortem. Lairage time did not affect and did not interact with the effect of ES on any of the measured meat quality parameters. ES did not affect the u ltimate pH in LD, BF, SM and SC or internal reflection value in LD. However , ES caused higher internal reflection and drip loss in BF and increased th e PSE frequency in LD (2 to 7%) and in BF (2 to 49%). The frequency of PSE areas in the centre of SM was 70% for ES pigs compared to 9% for control pi gs. ES and ageing improved the tenderness and reduced the hardness in LD as well as shear force of unaged BF. The effect of ES on tenderness and hardn ess was approximately half the effect of ageing, but the effect of ES and a geing were additive. ES significantly increased the activities of cathepsin B + L in the myofibrillar fraction, but there were no differences in prote olytic activity in the other fractions. It is concluded that ES improves te nderness in LD and BF, but has a negative effect on the quality of BF and S M. Therefore ES is not an economically attractive alternative for improveme nt of tenderness in LD compared to ageing in Danish pigs. (C) 1999 Elsevier Science Ltd. All rights reserved.