Intelligent pH-Sensitive Indicator Based on Chitosan@PVP Containing Extracted Anthocyanin and Reinforced with Sulfur Nanoparticles: Structure, Characteristic and Application in Food Packaging

Foodborne infections represent a real public health problem and are classified as notifiable communicable diseases. Their frequency remains high despite the surveillance and prevention measures taken during the production, distribution, and conservation of food. Consequently, the control of these infections must be a priority in terms of food safety. The use of intelligent and active food packaging has become a major priority. Those materials act as barrier films, predict the quality changes and makes sure that food is protected, preserved, and safe to be used. The main objective of this study was to develop pH-sensitive functional food packaging films based on chitosan/poly (vinyl pyrrolidone) (CS @PVP) incorporated with sulfur nanoparticles (SNPs) and red cabbage anthocyanin (ATC). Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, mechanical testing, and surface hydrophobicity were used to analyze the produced additives and films. The antioxidative activity of packaging films was investigated by the 2, 2-diphenyl-1-picrylhydrazyl radical method. It was found that after the incorporation of SNPs into the CS @PVP matrix, the transparency, tensile strength, moisture absorption, water vapor permeability, and light transmission were reduced, while ATC-containing films have much higher antioxidant activity than virgin CS @PVP film. Moreover, the synthesized film provides the ability to change color between red and green with a pH range from 2 to 12. The bio-nanocomposite film CS @ PVP-ATC containing sulfur nanoparticles (SNPs) can be applied as a multifunctional food packaging allowing the prediction of the quality changes in fresh meat and extending its shelf life. [GRAPHICS] .