Diacetyl delays the postharvest quality degradation of apple fruit

Delaying the quality degradation of postharvest apple is necessary to reduce economic loss. In present search, we investigated the impact of diacetyl on the quality of postharvest apples during storage. Diacetyl significantly maintained the levels of total soluble solid (TSS) and titrable acid (TA) in apple fruit. Moreover, diacetyl reduced the accumulation of reactive oxygen species (ROS) via increasing activities of antioxidant enzymes and total phenolics. Additionally, cellulose and pectin were maintained by diacetyl, whereas polygalacturonase (PG) activity was inhibited. Transcriptome analysis revealed that diacetyl could enhance resistance to external stresses and reduce ethylene accumulation. Meanwhile, genes related to ethylene synthesis, pectin degradation, starch degradation, cellulose synthesis, and malate transport were regulated by diacetyl to delay the quality degradation in postharvest apples. Our findings demonstrated that diacetyl could enhance storage performance of apples. And, this study provided theoretical support for the development of a new postharvest storage technology for apples. • A novel role of diacetyl in delaying the storage quality degradation of apple. • Diacetyl enhances the antioxidation of apple. • Diacetyl inhibits the accumulation of ethylene in apple.