Development and evaluation of biodegradable starch-based films containing cellulose nanocrystals/titanium dioxide nanoparticles as an alternative for food packaging

Abstract

Biodegradable starch-based films are an environmentally friendly solution to reduce the use of petroleum-derived polymers. Thus, this work aims to obtain corn starch films by incorporating 5% w/w of cellulose nanocrystals (CNC), different concentrations of titanium dioxide nanoparticles (TiO2) (0, 0.25, 0.5, 1, and 2% w/w), and 40% w/w of glycerol and sorbitol (plasticizers), in a 1:1 ratio. The films showed a high potential for UV-light barrier, with an increase of 307% incorporating only 2 wt% of TiO2 in relation to the film without incorporation of TiO2. The use of TiO2 increased the white pigmentation capacity of the samples and decreased the lower water solubility – a reduction of approximately 28% using 0.5 wt% TiO2 compared to the CNC control sample was observed. The incorporation of TiO2 nanoparticles increased the tensile strength by adding 1 wt% of TiO2 nanoparticles with 34% increase in the tensile strength of the film without incorporation of TiO2. The thermal stability of the films with 1 wt% TiO2 and 5 wt% CNC increased by 85°C. Thus, the addition of CNC and TiO2 enabled an improvement in the physical/thermal/chemical properties of the films, making them possible alternatives for use in food packaging.