Antifungal Mechanism, Microencapsulation, and Postharvest Application of Citral Against Botrytis cinerea in Blueberries

Citral inhibited Botrytis cinerea by disrupting fungal barriers and homeostasis. • T3O1 silica microcapsules enabled sustained citral release (65.16% over 30 days). • Citral microcapsules delayed decay and preserved blueberry quality. Botrytis cinerea is a major postharvest pathogen causing substantial quality losses in blueberries. Citral is a promising natural antifungal agent, but its high volatility, oxidation sensitivity, and poor stability limit practical application. This study investigated the antifungal mechanism of citral against B. cinerea and developed citral-loaded tetraethyl orthosilicate octyltriethoxysilane (TEOS/OTES) hybrid silica microcapsules for controlled release. Citral strongly inhibited mycelial growth, with a minimum inhibitory concentration (MIC) of 0.5 μL/mL, and caused morphological and ultrastructural damage. It disrupted cell wall and membrane integrity, induced reactive oxygen species (ROS) accumulation, impaired mitochondrial function, and suppressed ATP-related energy metabolism. The optimized T3O1 microcapsules exhibited favorable stability and sustained release, reaching 65.16 % cumulative citral release over 30 d. Compared with free citral, the microcapsules more effectively reduced blueberry decay and weight loss, maintained firmness and membrane integrity, preserved nutritional and bioactive compounds, enhanced antioxidant enzyme activities, and suppressed polyphenol oxidase activity. These findings support TEOS/OTES microencapsulation as a natural controlled-release strategy for improving citral stability and maintaining postharvest blueberry quality. Download: Download high-res image (404KB) Download: Download full-size image