Active whey protein isolate films including bergamot oil emulsion stabilized by nanocellulose

The aim of this study was to develop whey protein isolate (WPI) films incorporated with bergamot oil (BO) in the form of nanoemulsion stabilized with nanocellulose (NC). WPI films were prepared by incorporating different concentrations of BO and NC-stabilized BO (0-40%, w/w). The mechanical properties of neat WPI films were improved with the inclusion of NC-stabilized BO emulsion (p < 0.05). Water vapor permeability of WPI films decreased with the increase in BO content up to 20 % concentration (p < 0.05) and then started to increase. The increase in BO content also caused a decrease in transmittance and lightness confirming higher opacity values (p < 0.05). Scanning electron microscopy images showed that films including NC presented more homogeneous surfaces. The release rate of films including NC-stabilized BO was slower than WPI films directly incorporated with BO. The incorporation of BO with or without NC provide a noticeable antimicrobial and antioxidant activity to WPI films.