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Electrical stimulation of prerigor beef carcasses produced a rapid initial drop in pH of longissimus muscles excised and vacuum-packaged at 1, 2 or 4 h postmortem. This initial drop was further increased by delayed excision and was severe enough that even -30-C storage did not retard the overall decline. Through the first 10 h of the 30-h sampling period at -30 C, pH was higher for nonstimulated than for stimulated muscle and was substantially affected by the time of muscle excision. Compared to -30-C storage, a 3-C storage temperature resulted in an even faster decline of pH in electrically stimulated muscle but still hindered the decline in nonstimulated muscle. Although the decline in pH was affected by electrical stimulation, excision time and storage method, initial (time of excision) and final (5 days postmortem) sarcomere length were not. Electrical stimulation of prerigor beef carcasses did not affect the appearance of hot-boned or cold-boned longissimus or semimembranosus muscles. Excision time, however, did affect the color and color uniformity of semimembranosus muscles, apparently because of alteration of the temperature and pH relationship. Excision times of 1 or 2 h appear preferable to 4 or 48 h because combinations of high temperature and low pH within deeper areas of the carcass could cause severe non-uniformity of color in muscles set deep within the carcass.

Effects of eight grinding methods on textural properties of cooked beef patties were tested on beef from two sources. The methods tested were representative of those used by processors throughout the country and the sources were U.S. Choice chucks and U.S. Utility grade triangles. Patties from the .32 × .32 cm and silent cutter methods scored highest for tenderness and were lowest in amounts of subjectively determined connective tissue for both Choice and Utility grade beef. Sensory panel and Instron means indicated that the size of plate for initial grind was related (P < .10) to tenderness and the amount of connective tissue in the final product. Patties prepared by the 2.54 × .32 cm grinding method were generally inferior to patties prepared by the .32 × .32 cm grinding method.

A coring device for sampling meat surfaces was developed. Aerobic plate counts of beef and pork carcasses were significantly higher when determined by the coring method than by the cotton or alginate swab technique.