DOES ELECTRICAL-STIMULATION AFFECT THE SPEED OF AGING OR AGING RESPONSE

During a 21 days ageing period, shear force, myofibrillar protein degr adation, proteinase activities, and collagen content and solubiity of electrically stimulated (8 or 64 s, 85 V, 14 Hz) and non-stimulated be ef longissimus muscle, were measured. In addition, water-holding capac ity and colour stability were assessed. Electrical stimulation for 64 s (ES64) accelerated myofibrillar protein degradation, but inhibited t otal myofibrillar protein degradation (at 21 days post mortem). Compar ed to the other treatments, ES64 resulted in a faster release of lysos omal enzymes into the sacroplasmic fraction and in lower mu-calpain ac tivity at 1.5 h post mortem. The effects of ES64 on myofibrillar prote in degradation and proteinase activities were not clearly reflected in differences in shear force. Collagen solubility, colour stability and drip loss were not affected, and cooking losses were increased as a r esult of stimulation. As intensive stimulation largely affected mu-cal pain activity, but not tenderisation, it is concluded that mu-calpain activity alone cannot account for tenderisation.