The physical properties, antioxidant and antimicrobial activity of chitosan-gelatin edible films incorporated with the extract from hop plant

The aim of this study was to develop active films based on blends of gelatin and/or chitosan containing different bioactive agents (hop extract, hop alpha-acids, or hop beta-acids). The physical, mechanical, optical, structural, and barrier properties, as well as antioxidant and antibacterial activity of the resulting films were characterized and investigated. The results indicate that films based on blends of gelatin and/or chitosan have extremely good mechanical properties, which are further improved upon the addition of bioactive agents. All films with bioactive agents showed better ultraviolet light barrier properties than those without bioactive agents, conferring an advantage in protecting food against oxidizing reactions. Fourier transform infrared spectroscopy analysis confirmed that there were interactions between bioactive agents and the biopolymers. In addition, chitosan and/or gelatin edible films containing bioactive agents demonstrated strong antioxidant activities. They were also shown to have antimicrobial activity and to be more effective against Gram-positive than against Gram-negative bacteria.

Automated summary

The study developed active films based on blends of gelatin and/or chitosan with different bioactive agents, showing improved mechanical properties and better UV light barrier properties with the addition of bioactive agents. The films exhibited strong antioxidant and antimicrobial activities, especially against Gram-positive bacteria, indicating potential for food preservation and safety. Interaction between bioactive agents and biopolymers was confirmed by FTIR analysis.