Metabolomic analysis of meju during fermentation by ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF MS)

► Changes in the water-soluble metabolites of meju during fermentation were analysed. ► Amino acids, peptides, and urea cycle intermediates as the major metabolites of meju. ► These metabolites related to the sensory quality can be used as biomarkers for meju. ► Based on discovering the metabolites, a tentative fermentation pathway was proposed.