Exploring the role of protein DJ-1 in quality of pale, soft and exudative (PSE) and red, firm and non-exudative (RFN) pork during post-mortem aging

The purpose of this study was to investigate the changes of oxidative attributes, protein DJ-1 expression, oxidized form (oxDJ-1), and cellular localization in RFN and PSE pork meat during the post-mortem aging. The longissimus thoracis of RFN and PSE groups were collected and classified by determination of pH, color and purge loss and then aged for 1, 3 and 7 d at 4 °C postmortem. Results showed that the content of DJ-1 and oxDJ-1 was continuously increased during 7 d of postmortem aging. A relatively higher protein DJ-1, oxDJ-1, oxygen reactive species and disulfide bond contents were found in PSE meat in comparison to RFN meat. Immunostaining showed that protein DJ-1 was located in cytoplasm, membrane and some nucleus of muscle cells. DJ-1 was shown to correlate with meat quality and oxidative attributes, suggesting a regulatory role in resisting oxidative stress and meat quality formation during post-mortem aging.