A new histopathology scoring protocol reveals myopathy features in PSE-like pork

Pale, Soft, and Exudative (PSE)-like pork defects are associated with fiber destruction and pale discoloration and have become a severe economic burden for the European meat sector. However, robust detection of PSE-like pork and its diverse features is challenging and makes studies into defect causation difficult. Implementation of histological examination may improve our knowledge about less-known features linked to PSE-like defects. Here we evaluate if a new histological protocol can reveal how myopathy in ham may be associated with visual and traditional physicochemical anomalies of PSE-like pork. We first created a list of pathological features, quantified them, and integrated them into a myodegeneration scoring scheme (MYO) for semimembranosus muscle sections. We then explored potential associations between overall MYO scoring and individual histology features with visual PSE-like defect scoring (DES) and with individual meat quality variables [pH_u, color: L*, a*, b* (CIELAB), bioimpedance, and near-infrared spectroscopy (NIR)]. As the primary finding of this study, we show a significant association between overall myopathy (MYO) scoring and PSE-like defect (DES) scores. We also found associations of specific myopathy features with DES scores, and of overall MYO scoring with specific quality variables. In all, our data suggest links between signs of acute myodegeneration and PSE-like defects. Our data, hence, supports the implementation of semi-quantitative histopathological approaches for diagnosing PSE-like pork features and may help identify the underlying mechanisms behind these defects.