Salicylic acid enhances postharvest blueberry quality by maintaining phenolic acids and improving aroma volatiles during storage

Blueberries are prone to softening, decay, and flavor loss. This study investigated the effects of salicylic acid (SA) on the quality, phenolic acid content, and aroma profile of blueberries. Blueberries were treated with 0, 0.5, 1, and 1.5 mmol L−1 SA and then stored at 4 ± 0.5°C for 20 days. Results indicated that treatment with 1 mmol L-1 SA effectively preserved appearance, reduced decay incidence, delayed firmness decline, and maintained higher levels of total soluble solids (TSS) and titratable acidity (TA). Additionally, SA significantly slowed the degradation of total phenols, total flavonoids, and anthocyanins, while increasing the levels of phenolic acids, including chlorogenic acid, caffeic acid, and ferulic acid. Concurrently, SA mitigated aroma loss by sustaining higher levels of key volatile organic compounds (VOCs) such as linalool and geraniol. Further analysis revealed that SA maintained the stability of VOCs by inhibiting the activities of phospholipase A (PLA) and lipoxygenase (LOX), and modulating the activities of hydroperoxide lyase (HPL), alcohol dehydrogenase (ADH), and alcohol acyltransferase (AAT). In conclusion, SA effectively delays postharvest quality deterioration, phenolic acid degradation, and aroma loss in blueberries, providing a theoretical basis for the green preservation of berries.