Abstract: To understand the composition and dynamic changes of primary metabolites in ‘Fuhong’ plum fruits during refrigeration, the primary metabolite profile of ‘Fuhong’ plum fruits stored at 4 ℃ for 0, 30, and 60 days was analyzed using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Differential metabolites were selected by orthogonal partial least squares-discriminant analysis (OPLS-DA) and subjected to pathway enrichment analysis. The results showed that a total of 573 metabolites were identified, including sugars, organic acids, amino acids and their derivatives, lipids, and nucleotides. There was a significant difference in primary metabolite profile between the three storage times, and 95 differential metabolites at day 30 vs. 0, 99 differential metabolites at day 60 vs. 30, and 173 differential metabolites at day 60 vs. 0 were identified. The pathway enrichment analysis showed that the major metabolic pathways with a significant difference included linoleic acid metabolism, unsaturated fatty acid biosynthesis, propionic acid metabolism, sulfur metabolism, purine metabolism, nucleotide metabolism, cysteine and methionine metabolism. This study provides a theoretical basis for the quality evaluation and postharvest preservation of ‘Fuhong’ plum fruits.

Key words: ‘Fuhong’ plum; refrigeration; ultra-high performance liquid chromatography-tandem mass spectrometry; primary metabolites