Although sheep is one of the significant red meat sources in most countries, the native sheep breeds in developing countries are usually small and grow slowly. In addition to genetic characteristic of these native sheep breeds, sheep farmers in third world countries prefer to utilize free public pastures as long as possible. The sheep producers aim to raise sheep that produce heavier carcasses for more income. Therefore, generally old sheep are the animals slaughtered in developing countries. Also, as living standards increase, consumers are demanding increased quality (more tender) meat. There have been many factors reported to influence meat quality of sheep (Sanudo et al., 1998) which would include tenderness and mutton flavor. The results of research conducted by Tatum et al. (1978) showed that the eating preferences of a consumer were consistently in favor of meat from younger animals due to a more tender tissue. It is well known that advanced chronological age and/or increased physiological maturity are usually associated with toughness of lamb and also mutton flavor. As a consequence of age-associated problems with tenderness, the majority of old ewes are commonly sold for a low price or the tissue is used in comminuted meat. A consistent method for increasing tenderness to a more acceptable level would transform mutton carcasses into a product that might be marketed through retail channels, allowing for increased flexibility in merchandising.
Although a great deal of research has been conducted on the effects of ES on many species, comparatively less research has been conducted on mature sheep carcasses. If tenderness of the ovine carcasses can be improved by employing ES, mutton would be more acceptable in restaurants, hotels or institutions in developing countries. Mutton could also be sold through retail channels to consumers in the many areas of the world and that would increase the utilization of mutton. This research was undertaken to determine the influence of electrical stimulation on some organoleptic and instrumental quality characteristics of Longissimus dorsi (LD) and Semimembranosus (SM) muscles from mutton carcasses of old ewes.