| Scope and Method of Study. Although the recent developments in meat science revealed that electrical stimulation (ES) of the carcass provided many quality advantages, little information is available on the most appropriate combination of electrical parameters for stimulating animal carcasses. This study was undertaken to evaluate the effectiveness of ES at different voltages (V) and frequencies (Hz) on some biochemical and quality characteristics of ovine muscles, and to investigate the combined effect of ES and mode of chilling of lamb carcasses on some biochemical changes of specific muscles. In the first portion of the study, twenty-one lambs were used. The sides were electrically stimulated at the assigned voltages and frequencies within 15 minutes postmortem for four minutes. During ES, the physical response of the sides was noted, and the electrical energy values were calculated. The pH, temperature, time required for the muscles to reach pH 6.0, Ca('++)-induced shortening, and solubility of muscle proteins were determined. The second study utilized twelve animals. Stimulating procedure was similar to the first study except the electrical parameters were fixed at 350 V and 10 Hz. The sides were randomly assigned to four treatments of different combinations of ES and mode of chilling. The pH, temperature, muscle shortening, cooking loss, shear force, lean color, and muscle protein solubility were determined.;Findings and Conclusions. In the first study, the ES treatment of 350 V with 10 Hz resulted in faster postmortem muscle glycolysis and less Ca('++)-induced shortening than did the other treatments. This treatment also provided the greatest energy per pulse and showed fast and vigorous twitching of most muscles during stimulation. The results concluded that ES with high voltage and low frequency was more effective in accelerating the postmortem glycolysis than ES of low voltage with high frequency. Data from the second study showed that electrically stimulated and slowly chilled sides exhibited more rapid pH decline, less cold shortening and greater tenderness than sides chilled at 2(DEGREES)C. Neither the lean color nor the solubility of different protein fractions were influenced by ES or mode of chilling. |
