EFFECT OF CHILLING TEMPERATURE ON POSTMORTEM CHANGES, MICROBIAL LOAD AND TENDERNESS IN BEEF

Publisher Website
Google Scholar
Abstract
Postmortem chilling temperatures of −2 and 3°C were utilized for 10 pairs of beef sides. Temperature decline during carcass chilling was characterized for the following eight locations: deep round, biceps femoris, semitendinosus, gluteus medius, adductor, longissimus (thirdfourth lumbar and twelfth‐thirteenth thoracic vertebrae junctions) and triceps brachii muscles. Sarcomere length and Warner‐Bratzler shear values for each of the above muscles and microbial count and shrinkage of carcass sides were determined. Temperature decline indicated that the early postmortem changes in muscle temperature vary immensely throughout the carcass. Chilling carcasses at 3°C as compared to −2°C decreased muscle shortening; however, the effect was pronounced only in the gluteus medius muscle and the longissimus at the twelfth‐ and thirteenth‐thoracic vertebrae junction. These observations are discussed with respect to the time‐temperature history of muscles during the early postmortem periods. Warner‐Bratzler shear values for muscles of carcasses chilled at 3°C were equal to or lower than shear values for carcasses chilled at −2°C, but no substantial reduction of toughening was observed due to the elevated chilling treatment. Microbial growth and carcass shrinkage at 3°C were comparable to that at −2°C.