Active Tara Gum/PVA Blend Films with Curcumin-Loaded CTAC Brush-TEMPO-Oxidized Cellulose Nanocrystals

Active films containing curcumin exhibit outstanding antioxidant and antibacterial properties. Because of curcumin's poor solubility in water, cetyltrimethylammonium chloride (CTAC) brush-TEMPO-oxidized cellulose nanocrystal (TCN) colloidal systems were prepared to be used as a delivery excipient to modulate the hosting of curcumin. The curcumin-loaded cellulose nanocrystals were incorporated in a tara gum/PVA blend film to prepare antioxidant and antibacterial films. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) measurements, transmission electron microscope (TEM), and solid-state C-13 NMR spectroscopy were performed to characterize the products. The results indicate the synthesis of TCN with a carboxyl content of 1.1878 mmol/g and 0.71 degree of substitution of CTAC based on carboxyl groups. There was 26.57% of the curcumin bound in the brush. The mechanical properties and barrier properties of the films were characterized. DPPH and ABTS(+) assays were used to measure the antioxidant properties. The activities against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria were also evaluated. The release of curcumin from the films into food simulants were also characterized to determine whether the antioxidants could provide intermediate protection from lipid oxidation. The results show that the mechanical and barrier properties of the films improved although water the vapor permeability slightly decreased. The film possessed desirable antioxidant and antibacterial properties. The release test revealed that curcumin was initially released rapidly into 50% ethanol solution and then released more slowly into the bulk. This suggests that the film could provide short-term protection from food oxidation. The films can be used for prolonging the shelf life of packed fat-rich foods.