Effect of volatile compounds produced by Wickerhamomyces anomalus induced with chitosan against blue mold disease in table grapes.

Antagonistic yeasts, such as Wickerhamomyces anomalus, produce volatile organic compounds (VOCs) that serve as antifungals or biostimulants. Previous studies have demonstrated the efficacy of W. anomalus VOCs in inhibiting fruit decay caused by pathogenic microorganisms. Our research indicates that culturing W. anomalus with 1 % chitosan enhances its ability to combat blue mold on fresh table grapes. Given that VOC production is a primary disease control mechanism for this yeast, we investigated whether 1 % chitosan could increase W. anomalus's VOC production. We examined the effects of culturing W. anomalus with 1 % chitosan on VOC production and its efficacy in managing blue mold in table grapes. Additionally, we assessed the impact of these VOCs on postharvest storage quality and grape enzyme activities, focusing on the regulation of reactive oxygen species (ROS) through enzyme activities and related substances. Our results showed that 1 % chitosan incubation promoted VOC production in W. anomalus, enhanced biocontrol efficacy against P. expansum, and reduced natural rot rates without compromising fruit quality. Moreover, disease resistance enzyme activity and ROS scavenging capacity in table grapes were improved. In conclusion, 1 % chitosan enhances the VOC production of W. anomalus, thereby increasing its antimicrobial efficiency.