Late-Breaking: Metabolome analysis of porcine fast and slow type muscles during postmortem aging

To clarify the temporal changes of key compounds for meat sensory and nutritional quality during postmortem aging, metabolome analysis was conducted in porcine different types of muscles, the longissimus lumborum (LL) and vastus intermedius (VI). Muscle samples were excised from three Landrace×Large White×Duroc breed female pigs at 0, 4, 24, 168 h postmortem, and were applied to capillary electrophoresis- time of flight mass spectrometry (CE-TOFMS). In total, 188 annotated peaks were detected. A number of annotated metabolites that showed differences between aging time points or between muscles were related to glycolytic pathway, TCA cycle, purine and pyrimidine metabolism, and amino acid metabolism. We focused on postmortem changes in some of essential nutrients and functional ingredients, such as choline, thiamine and gluconic acid. Choline increased in VI from 24 h to 168 h, but not in LL during aging. The choline content was higher in VI than in LL at 4, 24 and 168 h postmortem (P < 0.05). Thiamin (vitamin B1) increased from 24 h to 168 h in both muscles. Inversely, the content of thiamine triphosphate decreased during the aging period. The thiamin content was higher in LL than in VI at 168 h (P < 0.01). Gluconic acid, an enhancer of bifidobacteria growth in human intestinal microbiota greatly increased in LL from 24 h to 168 h, and the content was higher in LL than in VI at all time points of aging (P < 0.01). Thus, the contents of choline, thiamine and gluconic acid changed differently between muscle types during postmortem aging. In conclusion, our results revealed global metabolic changes during postmortem aging and the intermuscular difference in porcine muscle metabolites, including essential nutrients.