Soluble solids content-based fruit maturity affects postharvest fruit quality by mediating metabolic alterations in cold-stored ‘Autumn Sense’ hardy kiwifruit

This study evaluated the impact of soluble solids content (SSC)-based maturity on fruit quality and non-targeted metabolite profiles of cold-stored 'Autumn Sense' hardy kiwifruit. Noticeable alteration of glycolysis, the tricarboxylic acid cycle, and the amino acid and fatty acid pathways were observed during vine maturation of fruit. The branched-chain and aromatic amino acids were enriched at early harvest (5.7 % SSC), whereas pyruvate metabolism and unsaturated fatty acid biosynthesis were upregulated at late harvest (7.9 % SSC) during cold storage. These metabolic shifts were related to either incomplete ripening in early-harvested fruit or enhanced physiological disorders in late-harvested fruit. Our findings provide the first evidence that SSC-based harvest maturity mediates postharvest hardy kiwifruit quality through specific metabolic pathways. This study suggested that fruit with approximately 7 % SSC exhibited the most balanced metabolic profile and postharvest quality, suggesting this range as a preliminary optimal harvest maturity stage for 'Autumn Sense' hardy kiwifruit.