Antifungal features and properties of Pickering emulsion coating from alginate/lemongrass oil/cellulose nanofibers

Abstract

Summary This study investigated the antifungal features of sodium alginate (Alg) 1% combined with lemongrass essential oil (LGO) 0.25%, 0.5% and 0.75% as a Pickering emulsion coating to control Penicillium digitatum and P. italicum, identified as citrus fruit pathogens. Cellulose nanofibers 0.24%, 42.55 ± 9.34 nm, were selected as a stabiliser. Confocal laser scanning microscopy and Fourier‐transform infrared spectroscopy were used to analyse the droplet size and morphology and chemical interaction of emulsified coating, respectively. The effective dosage of lemongrass oil (0.75%) may enhance the antifungal action confirmed with a series of in vitro tests on spore germination by 88.28% (P. digitatum) and 91.94% (P. italicum), germ tube elongation by 89.28% (P. digitatum) and 90.13% (P. italicum) and membrane integrity by 41.67% (P. digitatum) and 63% (P. italicum). Additionally, the incorporation of LGO Pickering emulsion improved the beneficial properties of Alg‐based coating film, including light transmission at UV and visible light wavelengths and hydrophobicity. Scanning electron microscopy was performed to evaluate the interior microstructure of the coating film. Pickering emulsion‐based coatings described in this study may have potential applications for active packaging, particularly for citrus fruit commodities.