Abstract
PSE- and nonPSE porcine muscles were selected as the samples of this biochemical research, according to the characteristic pH values in carcasses of 60-90 minutes after slaughter. The activities of lysosomal enzymes and the nature of myofibrils from the muscles were investigated, and the following results were obtained. Between the PSE- and nonPSE samples, no significant differences were observed in specific activities of acid phosphatase, β-glucuronidase and N-acetylglucosaminidase of lysosomes. On the other hand, ATPases (EDTA-, Ca-, Mg-, and Mg·EGTA-) of myofibrils showed remarkably low activity values in PSE muscle. The heat-induced gel strength of myofibrils prepared from PSE muscle was lower than that of nonPSE muscle, both in the presence and absence of pyrophosphate. SDS-Polyacrylamide gel electrophoretogram of myofibrils from PSE muscle showed two additional bands to the gel from nonPSE muscle. From these results, it was suggested that the abnormal nature in PSE muscle is mainly due to the denaturation of myosin, and not due to the pathological factors concerning to the lysosomal enzymes.
