Variations in Low Electrical Stimulator Voltage Settings Minimally Influence Beef Longissimus Muscle Slice Shear Force Values

The objective of the current study was to evaluate the effect of differing electrical stimulation (ES) voltage levels on beef longissimus muscle tenderness, postmortem temperature, pH decline, and carcass quality. Beef carcasses from 3 commercial beef processing plants (A, B, C) were exposed to 3 varying voltage levels: (1) control (no ES), (2) ES level 1 (ES1; 60 Hz for 17 s each at 16, 20, 24, and 28 V), and (3) ES level 2 (ES2; 60 Hz for 17 s each at 25, 35, 45, and 55 V) prior to chilling. Ninety beef carcasses were selected from each of the 3 plants, and within a carcass, paired sides were randomly assigned to one of 3 ES treatments (n = 60 sides/treatment/plant). The results indicated that ES affected (P < 0.05) muscle pH at 3 h postmortem in 2 of the 3 plants. However, ES did not affect (P > 0.05) pH at the time of grading (postrigor). Although the slice shear force (SSF) values were lower (P < 0.05) for ES steaks compared with controls, voltage did not affect (P > 0.05) SSF values. Variation in SSF was observed among the plants (P < 0.05), with steaks from Plant C having greater (P < 0.05) SSF values compared with steaks from Plants A and B, which exhibited similar (P > 0.05) SSF values. Overall, although ES steaks had lower SSF values compared with control steaks, the lack of difference in postmortem tenderness between ES1 and ES2 voltage settings indicated that the low ES voltages minimally influenced SSF values.