Microstructure and Antimicrobial Functionality of Nano-Enhanced Protein-Based Biopolymers

Abstract. Whey protein isolates (WPI) and corn zein protein (CZP) films, embedded with porous silica-coated titanium nano-enhancers (TiO 2 @@SiO 2 ), were prepared and exhibited enhanced antimicrobial functionality. Protein solutions at 5% WPI and 13.5% CZP were amended with 1.5% w/w of TiO 2 @@SiO 2 nano-enhancers and subjected to sonication at 0, 16, 80, and 160 I¼m amplitude prior to casting into films. The effects of sonication on nano-enhancer distribution and the structure and morphology of the resulting films were elucidated by transmission electron microscope (TEM). The surface structure of the films was altered by the presence of nano-enhancers. The nano-enhanced biopolymer films exhibited antimicrobial functionality under sunlight by effectively inhibiting bacterial growth. The nano-enhanced biopolymers can potentially be used to make active antimicrobial surface coatings or packaging films to inhibit or slow down microbial growth during storage.