GNPS - PROTEOMICS AND METABOLOMICS PROFILING OF MEAT EXUDATE TO UNDERSTAND THE IMPACT OF POSTMORTEM AGING ON OXIDATIVE STABILITY OF BEEF MUSCLES

The objective of this study was to characterize the major proteomes and metabolites present in beef exudate and determine their relationship with the color and oxidative quality of beef muscles. Beef loin (longissimus lumborum; LD) and tenderloin (psoas major; PM) muscles were cut into sections, individually vacuum-packaged, and aged for 9, 16 and 23 days. Following aging, the meat exudates were collected and analyzed for both proteomics and metabolomics profiles. Both analyses demonstrated that distinct proteins and metabolites clustered by different muscle types and aging times were detected from meat exudate, however, metabolomics profiling presented a greater capability in identifying different aging periods. The proteome profile of PM exudate exhibited a greater concentration of oxidative metabolism enzymes, while the LD exudate contained a higher abundance of glycolytic metabolism enzymes. Greater lipid, nucleotide, carnitine and glucoside metabolites were observed in LD and 23d exudates, further explaining potential postmortem energy metabolism. HSP70 and laminin proteins, together with glucosides metabolites identified in the exudates were correlated (P<0.1 and |r|>0.5) to muscle oxidative stability. The results indicated that meat exudate could be a viable analytical matrix to further understand postmortem metabolism and potentially generate unique biomarker combinations to predict meat quality attributes.