Microencapsulation of Eucalyptus globulus essential oil anti-fungal sachet against blue mold on peaches

Abstract

The present study was specifically designed to develop bio-fungicides that may help mitigate reliance on hazardous synthetic chemicals which give rise to environmental safety concerns. A survey (2021–2022) of local fruit markets in Islamabad, Pakistan included morpho-molecular disease identification. It revealed Penicillium chrysogenum as a major phytopathogenic fungi causing fruit rot. The fungicidal action of plant essential oils might be boosted by the technique of application therefore, nanoencapsulation of essential oil and chitosan was performed. To attain the objective of antimicrobial packaging, essential oil and chitosan tablets were encapsulated in spun bond sachets against P. chrysogenum using a sachet volatile phase technique. In vitro screening of nano encapsulated eucalyptus essential oil showed significant inhibition of radial growth of P. chrysogenum colonies at 1.6 mg · ml–1 followed by 1.4, 1.2 and 1.0 mg · ml –1. Results of Gas Chromatography and Mass Spectrometry revealed the presence of eucalyptol in eucalyptus EO as a major antifungal component. An in vivo experiment analyzing the efficacy of essential oil tablets against pre-inoculated peach fruit with P. chrysogenum at ambient temperatures (7–37°C) showed significant reduction in lesion diameter, disease severity and prolonged shelf-life of peaches of more than 2 weeks. The natural ripening process of peach was not affected by the presence of antifungal sachets as no significant alteration in weight loss of fruit was recorded. The suppressiveness of fungal mycelial growth of P. chrysogenum was directly proportional to increases in E. globulus oil concentration. This research may have a significant impact on prolonging the shelf-life of peach fruit.

Keywords

• nano-encapsulation
• penicillium chrysogenum
• postharvest fungal rot