High-Amylose Corn Starch/Konjac Glucomannan Composite Films Incorporating Nano TiO2 and Pomegranate Peel Extract and Their Application as Coatings on Agaricus bisporus

In this study, active packaging films were developed by incorporating nano TiO 2 and pomegranate peel extract (PPE) into high-amylose corn starch (HCS)/konjac glucomannan (KG) matrix for the first time. The aim of present work was to investigate the influence of nano TiO 2 and PPE on physicochemical and functional properties of HCS/KG-based films. The films were characterized by XRD, FT-IR and SEM, and the tensile, antibacterial and antioxidant properties were evaluated. The results showed that the crystallinity of the composite films was increased and the microstructure was more uniform and dense after adding TiO 2 and PPE, and the intermolecular hydrogen bonds were formed between TiO 2 , PPE, and film matrix. Incorporation of TiO 2 and PPE significantly improved tensile properties and decreased water solubility and water vapor permeability of the composite films (p < 0.05). HCS/KG films incorporated with TiO 2 and PPE presented remarkable antibacterial activity against Escherichia coli and Staphylococcus aureus , and exhibited strong antioxidant activity due to the polyphenol compounds in PPE. All films properties not only changed with the content of TiO 2 and PPE, but also improved synergistically when they were added together. The developed composite films were used as coating for the preservation of Agaricus bisporus , and the weight, firmness and total soluble solids of A. bisporus were significantly maintained and browning was effectively inhibited during storage. Therefore, HCS/KG composite film/coating containing TiO 2 and PPE has great potential as an attractive commercialization technology to ensure the quality and extend the shelf life of foods.