Characterization of biodegradable films based on carboxymethyl cellulose and citrus pectin films enriched with bee bread oil and thyme oil

Abstract

Films based on polysaccharides (e.g., cellulose esters, pectin) are often utilized as bio-packaging for food products. In this study, films were developed by casting method using carboxymethyl cellulose (CMC), pectin (P), and glycerol incorporated with two essential oils (EOs), bee bread oil (BBO) and thyme oil (TO) in different concentrations (1, 2, and 3%). The formulated films were described in terms of physicochemical properties, as well as through FT-IR spectroscopy, morphological, and thermogravimetric analysis, and with a focus on biodegradation degree. The addition of BBO to CMC films enhanced mechanical properties (77.22–81.96 MPa for tensile strength and 380.5–629.5 MPa for Young's modulus) and reduced barrier characteristics (0.46–0.74 g × mm/kPa × h × m² and 0.69–0.84 cc × mm/m² × atm × day for water vapor and oxygen permeabilities, respectively). The EOs decreased the films' opacity and increased their transparency. Considerably, films incorporating 2% and 3% of BBO and TO were completely degraded after 20 days of burial. Furthermore, principal functional groups and interaction between polymers and EOs were observed by FT-IR spectroscopy and morphological analysis of films.