Effects of ferulic acid and its esterified derivatives on <i>Botryosphaeria dothidea</i> and postharvest kiwifruit quality

This study explores the antifungal properties of ferulic acid (FA), ferulic acid methylester (FAM), and ferulic acid ethylester (FAE), against Botryosphaeria dothidea (B. dothidea), and their effects on the postharvest quality (decay rate, weight loss rate, total soluble solids, titratable acids, firmness, respiration rate) of "Hongyang" kiwifruit. The results demonstrated that FAE exhibited a stronger in vitro inhibitory effect on B. dothidea than FA and FAM, and offered superior preservation of kiwifruit quality after harvest. Scanning electron microscopy (SEM) images revealed that B. dothidea mycelium treated with FA, FAM, and FAE showed altered surface morphology, with signs of plasmolysis. Transmission electron microscopy (TEM) further confirmed that FAE caused significant damage to the cell membrane and organelles of B. dothidea. Additional analyses using propidium iodide (PI) and calcofluor fluorescence white (CFW) staining, conductivity tests, and alkaline phosphatase (AKP) assays demonstrated that FA, FAM, and FAE treatments compromised cell membrane integrity. In addition, FAE treatment reduced the decay rate of kiwifruit, delayed the softening process and respiratory peak, maintained firmness, and prolonged antioxidant enzyme activity, preserving the fruit's quality over time. These findings suggest that FAE is a potent antifungal agent against B. dothidea with potential applications as an eco-friendly solution for controlling postharvest soft rot in kiwifruit. PRACTICAL APPLICATION: This study explores the antifungal properties of ferulic acid (FA), ferulic acid methylester (FAM), and ferulic acid ethylester (FAE), against Botryosphaeria dothidea, and their effects on the postharvest quality of "Hongyang" kiwifruit. This work provides an eco-friendly solution for controlling postharvest soft rot in kiwifruit.