Antifungal efficiency of p-anisaldehyde nanoemulsions against Botrytis cinerea and its application in strawberry preservation

Strawberries with high nutritional content are highly vulnerable to decay due to the lack of protective peels and Botrytis cinerea ( B. cinerea ) infection. The natural compound p -Anisaldehyde (AS) showed great potential application in food preservation due to the efficient bioactive activities, while the hydrophobic and volatile properties of AS have limited the widespread application. Herein, the AS nanoemulsion (ASNE) was prepared and the antifungal activity and mechanisms against B. cinerea were investigated. Furthermore, the chitosan-based edible coating-films incorporating ASNE were developed to evaluate their preservative effects on strawberries. Results showed the prepared ASNE was nanometer-size emulsion with high homogeneity and stability, and the growth of B. cinerea was completely inhibited after exposure to ASNE at 6.25 μL/mL. Morphological ultrastructural observations suggested ASNE could significantly damage the mycelial morphology, disrupt the membrane integrity of fungal mycelia, and thereby resulting in the leakage of intracellular materials. In addition, ASNE could induce the intracellular reactive oxygen species production and accumulation, thereby leading to lipid peroxidation and membrane integrity destruction of B. cinerea mycelia. The results in the practical preservation test showed chitosan edible coating-films loaded with ASNE (CS/ASNE-12.5 edible coating-films) could reduce the weight loss, decay rate and hardness changes, and retard the microbial growth in strawberries during an 8-day storage period at 4 °C. These findings suggested that the fabricated CS/ASNE edible coating-films showed great potential in postharvest strawberry preservation.