Cellulose nanocrystals from pomegranate peel: isolation, characterization, and its reinforcement for chitosan film

The aim of this study was to prepare cellulose nanocrystals from pomegranate peel (PCNCs) and evaluate its reinforcement for chitosan film. Firstly, the pomegranate peel was chemically purified through alcohol, acid, bleaching, and alkali treatments for cellulose isolation. Later, PCNCs suspension was obtained by sulfuric acid hydrolysis. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric (TG) analysis proved the removal of lignin and hemicellulose. Morphology of PCNCs was observed using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The PCNCs displayed needle-like structures. The length and diameter was 130 +/- 68.39 and 5.22 +/- 1.40 nm, respectively. Chitosan films incorporated with different contents of PCNCs (0, 2, 4, 6%, based on chitosan) were fabricated and investigated. Results showed that PCNCs reduced the moisture content and water solubility, and enhanced the mechanical property, water vapor and light barrier properties of chitosan film. The thermal stability of chitosan film was not affected with the addition of PCNCs. These findings suggested that PCNCs as nanofiller could be used to improve the properties of chitosan film for food packaging. [GRAPHICS] .