The combined effects of time on feed, electrical stimulation and aging on beef quality

Abstract

Two experiments were conducted to determine the combined effects of time on feed, high-voltage electrical stimulation (HVES) and postmortem aging on beef quality and palatability. Increasing time on feed resulted in an increase in carcass fat thickness, dressed carcass weight and marbling and a decrease in carcass lean content, carcass shrinkage and shear values in both experiments. Steaks from longer-fed animals were rated more highly for juiciness, tenderness and overall palatability by the consumers polled. HVES lowered muscle pH (3, 24 and 144 h), increased subjectively appraised marbling fat, gave brighter, redder muscle colour up to 6 d postmortem, and improved consumer ratings for flavour, juiciness, tenderness and overall palatability. HVES also resulted in a significant improvement in shear values (shear values were decreased by 27 and 35% in experiments 1 and 2, respectively). Aging for 6 d improved meat colour, decreased the amount of expressible juice and lowered the shear value of steaks by 11 and 9% respectively, in experiments 1 and 2. A consumer survey indicated that more than 20% of steaks were rated as unacceptable for tenderness when time on feed and postmortem aging were similar to Canadian beef-production practices. Incorporation of HVES as a means of quality control would reduce the proportion of unacceptable steaks to approximately 10%. Key words: Beef quality, time on feed, electrical stimulation, aging