Nanocomposite active films based on arrowroot starch with carnauba wax nanoemulsion, cellulose nanocrystals, and Mentha spicata essential oil

Biopolymer films have been widely studied as food packaging materials, due to the environmental problems caused by food packaging based on polymers of petrochemical origin. An alternative to improve the properties of biopolymer films can be the use of nanoparticles as reinforcement agents and natural antimicrobial compounds. In this sense, arrowroot (AA) starch-based films incorporated with a nanoemulsion of carnauba wax (CWN), cellulose nanocrystals (CNCs) and essential oil of Mentha spicata (MEO) were produced by casting method and then characterized in terms of its water barrier, tensile proprieties and in vitro antifungal activity. The incorporation of CNCs decreased the moisture content and water vapor permeability of the AA/CWN/CNC film. The incorporation of CNCs increased the tensile strength of the AA/CWN film from 3.0 to 5.3 MPa. The tensile strength of the films with MEO (4.25-4.06 MPa) incorporated was lower than that of the AA/CWN/CNC film (5.3 MPa). However, all films were superior in tensile strength to the AA/CWN (3.0 MPa) control film without CNCs and MEO. The incorporation of MEO provided excellent inhibiting capacity of phytopathogenic fruit fungi, increasing the inhibition diameters to R. stolonifer from 16.0 to 25.2 mm and B. cinerea increased from 19.0 to 33.7 mm. Because of their water and tensile barrier properties and antifungal activity of AA/CWN/CNC/EO films have promising potential for application as active packaging for food products.