Cellulose acetate active films incorporated with oregano (Origanum vulgare) essential oil and organophilic montmorillonite clay control the growth of phytopathogenic fungi

The aim of the present study was to produce active films based on cellulose acetate (CAc) incorporated with different concentrations of oregano essential oil (OEO) and organophilic montmorillonite clay (MMT30B) to control the growth of phytopathogenic fungi. The active films were characterized by ATR-FTIR, XRD, TEM, mechanical resistance, WVTR, OTR, thermal stability, and antifungal activity against the phytopatogens Alternaria alternata, Geotrichum candidum, and Rhizopus stolonifer. The CAc-based active films presented high antifungal activity against the tested phytopathogens, mainly in vapor phase. MMT30B exhibit good dispersion in CAc matrix, resulting in a partially exfoliated conformation. In this way, MMT30B significantly increased films' rigidity and thermal resistance while reduced OTR. OEO acted as plasticizer, facilitating MMT30B dispersion. Also, OEO increased extensibility and decreased WVTR of CAc-based films. Both OEO and MMT30B slightly improved the thermal resistance of films. The active films developed here denote a potential packaging system for postharvest conservation purposes.