Konjac glucomannan/polyvinyl alcohol/citric acid–based active food-packaging films containing Polygonatum sibiricum polysaccharide

Biodegradable active packaging has recently attracted attention owing to its ability to solve environmental and food safety problems associated with traditional petroleum-based packaging. Herein, novel active food-packaging films were prepared using konjac glucomannan (KGM)/polyvinyl alcohol (PVA)/citric acid (CA) composites containing Polygonatum sibiricum polysaccharide (PSP) as the active agent. The effects of various PSP contents on the structure, physical properties and functionality of the composite films were investigated. Fourier transform infrared spectroscopy and scanning electron microscopy results revealed that hydrogen bonding within the films strengthened with increasing PSP content. X-ray diffraction results revealed that the addition of PSP improved the crystallinity of the composite films, and the tensile strength of the composite films reached the optimum when the PSP content is 0.2 %. Furthermore, at low contents (≤0.2 %), PSP was uniformly distributed in the composite films and exhibited good barrier, UV-shielding and antimicrobial properties. All composite films exhibited good antioxidant performance.The best sample (the composite film containing 0.2 % PSP) was successfully used for packaging strawberries; this film reduced the weight loss and extended the shelf life of strawberries. Thus, the fabricated films containing PSP have broad application prospects in food packaging.