Physical and morphological properties of hydroxypropyl methylcellulose films with curcumin polymorphs

Native curcumin (UC, untreated curcumin) was treated (TC, treated curcumin) using antisolvent precipitation technique and incorporated in hydroxypropyl methylcellulose (HPMC) based film solution. Curcumin particles and films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. In addition, thickness, moisture content, color, barrier permeability (water, O-2 and CO2), mechanical and thermal properties of films as well as the release of curcumin from film to food simulant was investigated. The results obtained by several techniques showed that TC polymorphs were obtained by antisolvent precipitation with lower particle size than native curcumin. HPMC films showed a partially crystalline structure and homogeneous distribution of ingredients analyzed by XRD and SEM, respectively. Thickness, moisture content, mechanical properties and water vapor permeability of HPMC films were not altered with the presence of UC or TC. A higher percentage of curcumin release (53.9%) was obtained for HPMC-TC films when compared with HPMC-UC films (curcumin release of 7.9%). Results suggest that HPMC films containing TC by antisolvent precipitation could be used as active packaging in the food industry.