Cinnamon Essential Oil Encapsulated into a Fish Gelatin-Bacterial Cellulose Nanocrystals Complex and Active Films Thereof

In this study, cinnamon essential oil (CEO) nanocapsules were stabilized by means of bacterial cellulose nanocrystals (BCNCs) and encapsulated using fish gelatin as the main polymer phase. Emulsions were prepared at pH 5 using different CEO concentrations (0.03, 0.06, 0.12, 0.24, 0.36, and 0.48% v/w) and a fixed amount of fish gelatin (3% w/w) and BCNCs (0.06% w/w). The controlled release of the essential oil was assessed by release studies, which revealed that the higher the CEO concentration, the lower the release rate of CEO. In addition, modelling of experimental data using five different equations showed that the best fitting was obtained for the Korsmeyer-Peppas model, according to which the CEO release obeyed a non-Fickian behavior. Films obtained from the same formulations were characterized in terms of optical properties (light transmittance and haze), surface wettability, barrier (oxygen, carbon dioxide, and water vapor transmission rates) and mechanical properties. It was observed that an increased amount of CEO in the films did not significantly affect both transparency and haze, while it yielded an increase in surface hydrophobicity (~ 120% increase in water contact angle over the control) and elongation. Finally, the barrier performances of films against O2, CO2, and water vapor suggest a potential application of CEO/GelA-BCNC matrices as antimicrobial layers (in the form of coatings deposited on plastic films or directly on food) in living foods that have a respiratory metabolism, such as modified atmosphere-packaged crustaceans and mollusks as well as fruits and vegetables. Graphical abstract: [Figure not available: see fulltext.]