Development of active food packaging materials incorporated with nanocellulose and investigation of their toxicity

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Nanocellulose is a renewable, lightweight, and biodegradable biomaterial that has potential applications in the food packaging industry. Nanocellulose can be used as a promising and versatile material in active food packages to improve their physical and functional properties or to bind bioactive agents (e.g. antioxidants and antimicrobials) in the packaging matrix. Nevertheless, there are increasing concerns regarding the potential toxicity of nanomaterials used in food packages since they may migrate into the food and pose safety risks to consumers. In this study, novel nanocellulose/soy protein nanocomposites and nanocellulose/metal nanoparticle nanocomposites were prepared via different approaches. Further, the toxicity of nanocellulose/metal nanoparticle nanocomposites to human colon cells and intestinal bacteria was evaluated. The results suggest the nanocellulose/soy protein nanocomposites containing pine needle extract (PNE) exhibited notable barrier capacity and antioxidant activity, which proved their potential as biodegradable active food packaging. The addition of PNE contributed antimicrobial capacity to soy protein-based nanocomposites, particularly in an acidic condition. Moreover, nanocellulose/silver nanoparticle nanocomposites displayed strong antimicrobial effects against foodborne pathogens and, thus, can be incorporated in food packaging for improving food safety, whereas nanocellulose/titanium dioxide nanoparticle nanocomposites were successfully loaded in poly(vinyl alcohol) (PVA)-based films to ameliorate their mechanical properties and light barrier capacity. The cytotoxicity study showed that the intestinal toxicity of nanocellulose/metal nanoparticle nanocomposites largely depended on the composite concentration, the release of metal ions, and the type and surface charge of metal nanoparticles. This project demonstrates the potential application of nanocellulose to develop novel nanocomposites for active food packaging.