Sustainable PLA-Citronella Essential Oil Films: Development and In Vitro Antifungal Evaluation for Potential...

Area of Science:

• Food Science
• Materials Science
• Mycology

Background:

• Postharvest fungal decay significantly impacts blueberry yield and shelf-life.
• Conventional fungicides pose environmental and health concerns, driving demand for sustainable alternatives.
• Biodegradable packaging offers a potential solution for extending fruit freshness.

Purpose of the Study:

• To develop and characterize polylactic acid (PLA) films incorporated with citronella essential oil.
• To evaluate the efficacy of these active films against key phytopathogenic fungi responsible for blueberry spoilage.
• To investigate the antifungal mechanism of citronella essential oil released from PLA films.

Main Methods:

• PLA films with varying concentrations of citronella essential oil (7.5-12.5%) were prepared using solvent casting.
• Films were analyzed for water vapor transmission rate and nanomechanical properties.
• In vitro antifungal activity was assessed against Epicoccum nigrum, Alternaria alternata, and Cladosporium herbarum.

Main Results:

• Active films demonstrated concentration-dependent antifungal activity, with Cladosporium herbarum being most susceptible.
• Citronella essential oil did not significantly affect the water vapor barrier properties of PLA films.
• Mechanical analysis showed a reduced elastic modulus at the highest citronella concentration.
• Microscopic and biochemical analyses indicated membrane disruption and morphological damage in fungal hyphae.

Conclusions:

• PLA-citronella essential oil films show significant potential as a biodegradable packaging solution for controlling postharvest blueberry fungal decay.
• The released citronella essential oil acts by disrupting fungal cell membranes.
• This approach offers a sustainable alternative to synthetic fungicides in fruit preservation.