Browning in turkey meat preparations and related changes in muscles after slaughtering. Morphopathological study.

Commercial samples of “arrosticini” (turkey meat) preparations packaged in modified atmosphere were investigated four days after packaging but before the expiration date for chromatic changes, consisting of greenish-brown foci of discoloration. After ruling out microbial causes, chemical, physical and histopathological studies were carried out on meat preparations and on tibialis cranialis and extensor digitorum longus muscles (both pre and post-rigor) from the same type of animal used for preparing the “arrosticini”. The pH values were similar in tibialis cranialis muscle from all turkeys examined indicating normal acidification, while the extensor digitorum longus muscle showed low acidification. High peroxide values were detected in all affected “arrosticini” samples. Histopathological investigations showed the presence of “giant” fibres both in samples of “arrosticini” with evident chromatic changes and in the muscles. These “giant” fibres, positive to ATPase reaction after alkaline pre-incubation and to the Periodic Acid Shiff (PAS) reaction, showed floccular necrosis, sarcoplasm fragmentation and hypercontraction of the fibres. These findings could be related in part to a recurring ischemia in the involved muscular areas that occurred in the living animals, probably due to their fast, excessive growth.