Starch and whey protein isolate films including an aroma compound stabilized by nanocellulose.

Abstract

Bergamot essential oil (BO) shows biological activities and is widely used as a flavoring for food products; however, its application in foods is limited because of the low stability and solubility in water. This study aimed to prepare whey protein isolate (WPI) and starch (S) films, including nanocellulose based BO nanoemulsions, potentially enhancing BO functionality. BO nanoemulsion was obtained by using a nanocellulose dispersion (2 mg/mL) including 3 mM CaCl2 with a ratio of 2/8 (v/v, BO/nanocellulose dispersion) and then suitably dispersed (2%, w/w) in the WPI and S film-forming solutions to obtain film samples. The water vapor permeability (WVP), mechanical and optical properties and BO's release from those obtained films were studied. The WVP (p<0.05) and tensile strength (p>0.05) of films were improved, whereas opacity increased with the addition of BO nanoemulsion (p<0.05). The release of BO from S films was faster than in WPI films. These results showed that nanocellulose could be used as carriers for essential oils such as BO to enhance its functionality within bio-polymeric matrices intended to be used as relevant carriers of aroma compounds.