Acetic acid treatment delays the quality deterioration of hawthorn fruit via regulation of ascorbate biosynthesis and regeneration

• AAC treatment delayed hawthorn fruit quality deterioration. • AAC treatment reduced ROS damage by enhancing antioxidant enzymes activities. • AAC treatment increased levels of AsA and GSH. • AAC treatment enhanced enzyme activities in AsA–GSH cycle. Hawthorn fruits are both medicinal and edible, with high nutritional and health-care value. However, harvested hawthorn fruits are prone to loss water and decay, which significantly shortens their fresh-keeping period. Treatments with different acetic acid (AAC) concentrations on the quality of ‘Qiujinxing’ hawthorn fruits was investigated. The findings revealed that compared with the untreated fruit, AAC treatment (especially at a concentration of 0.1 %) significantly delayed fruit senescence and maintained quality by inhibiting the ethylene release rate, weight loss rate and fruit decay. Moreover, compared to the control, hawthorn fruits treated with 0.1 % AAC exhibited significantly higher levels of flavonoids, anthocyanins, and total phenols, accompanied with elevated key antioxidant enzymes activities during the late storage phase. This enhanced antioxidant capacity was concomitant with a marked reduction of reactive oxygen species and MDA accumulation. Furthermore, AAC treatment significantly activated the ascorbate-glutathione (AsA-GSH) cycle related enzymes, including ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase and dehydroascorbate reductase, which resulted in elevated production of both AsA and GSH. Overall, AAC treatment might delay postharvest quality deterioration in hawthorn fruit through the modulation of AsA biosynthesis and regeneration, which holds promise as an environmentally friendly and effective storage strategy for guaranteeing the postharvest quality of hawthorn fruit.