Effects of polydextrose and curcumin on the physical, structural, and functional properties of gelatin-based film

Abstract

Gelatin (GEL) film has attracted considerable attention for food packaging because of its biodegradability, low cost, and exceptional film-forming ability. However, its poor physical and bioactive properties restrict its application. Taking polydextrose (PD) and curcumin (Cur) as functional ingredients, and their effects on the physical and functional properties of the gelatin film were investigated. With the addition of polydextrose (150%, according to the weight of gelatin), the thickness of the gelatin-based composite films increased 0.10 nm to 0.16 nm, while the water vapor permeability decreased from 729.8 g/m²·24 h to 615.3 g/m²·24 h. All gelatin-based composite films displayed a bright yellow-orange with the addition of 3% curcumin, and their 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity increased by more than nine times compared with neat gelatin films. Additionally, Fourier transform infrared spectroscopy and X-ray diffraction analyses suggested that incorporating polydextrose and curcumin into the gelatin-based composite film resulted in cross-linking through physical interactions without altering the crystal morphology of the molecules. Furthermore, gelatin-based film with polydextrose and curcumin were utilized for packaging apricot wraps, which reduced water loss during preservation and delayed spoilage. This study provides a strategy for preparing biodegradable GEL/PD/Cur films as packaging materials which can extend the shelf life of fresh fruit.