Effects of low-frequency electrical stimulation on beef tenderness

The application of 2 Hz, 500 V electrical stimulation to early post-mortem beef sides causes rapid muscle glycolysis, yet produces no trace of the extensive tissue rupture effected by 60 Hz current. By means of this low frequency technique, coupled with a mild or delayed-chill routine, we have examined the supposed tenderizing effect of rapid pH decline alone, without concurrent fiber fracture or cold-shortening intervention. Loin steaks from sides receiving this treatment were significantly tougher than those from paired control sides, an observation strongly suggesting that tenderization is hindered by rapid glycolysis. In other experiments, 60 Hz 500-V current was found to produce very extensive fracturing with breaks appearing (on average) every 6 mm of fiber length; this treatment resulted in a very significant tenderizing relative to that observed in the unstimulated control sides. It is concluded that, apart from its ability to prevent cold-shortening, normal-frequency high-voltage stimulation exerts its beneficial tenderizing action by fracturing the fibres; the accompanying acceleration of glycolysis actually causes a small, but definite, negative effect on eating quality.