Fabrication and Antifungal Activity of Cellulose Acetate-Based Fibers Encapsulating Natural Neem Seed Oil

摘要

Due to an attempt to increase the economic value of Thai neem (Azadirachta indica A. Juss. var. siamensis Valeton) as well as a concern on biosafety and environmental friendliness of a material that can be used for shelf-life extension of foods and perishable crops, this work was conducted to evaluate the antifungal property of NSO (NSO) and to fabricate and investigate the antifungal activity of NSO encapsulated in bio-based fibrous films. Natural cold-pressed NSO was first stabilized in micelles structure of sodium dodecyl sulfate (SDS) and then embedded in a composite matrix of cellulose acetate (CA) and poly(ethylene oxide) (PEO) via needleless electrospinning technique. The effects of SDS and NSO ratios in the electrospinning solution on the micelles size distribution, which in turn influenced the morphology of the e-spun fibers and payload of the encapsulated NSO, were investigated. Morphology of the fiber samples was examined via scanning electron microscopy (SEM). Fibrous films were selected to test for their in vivo antifungal property with wounded-inoculated and healthy tomatoes; Alternaria alternata was chosen as a tested fungus. As indicated by SEM images, an average fiber diameter was 900 nm. The results also showed that as the NSO ratio increased, the fibers tended to exhibit rice-grain-on-string microstructure. Electrospun fibrous film containing 50% NSO exhibited antifungal effect on wounded-inoculated tomatoes at a utilized weight ratio of the film to tomato of 125 mg film/1 kg tomato (in a 100% relative humidity controlled closed chamber).