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

Abstract

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