Preparation and characterization of PH-responsive polyvinyl alcohol/chitosan/anthocyanin films

Abstract

Anthocyanin/polyvinyl alcohol/chitosan composite membrane was prepared by solution casting method using chitosan (CS) and polyvinyl alcohol (PVA) as matrix and natural pigment anthocyanin as filler. The structures of the composite films were characterized by Uv-visible reflectance spectrum (UV-VIS), Fourier infrared spectroscopy (FT-IR) and the scanning electron microscopy (SEM). The effects of adding anthocyanins on the physical properties, water resistance, degradation, antibacterial properties and pH responsiveness of the films were investigated. The experimental results showed that the prepared anthocyanin/ polyvinyl alcohol/chitosan composite indicator films show color changes from pink to purple to blue and then to yellow-green when the pH value ranges from 2 to 14. The total color difference ΔE value is greater than 12. The antibacterial properties and other properties of the composite film can enhance by adding anthocyanin. The tensile strength of anthocyanin/polyvinyl alcohol/chitosan film is more than 70 MPa, which is larger than that of polyvinyl film and polyvinyl alcohol/chitosanfilm. The film has excellent physical, antibacterial properties and obvious pH response performance, making it ideal for food packaging.

Development of Environmentally Friendly and Intelligent Food Packaging Bio-Nanocomposite Films

“…However, the roughness gradually decreased upon the addition of 10% to 15% PSPE anthocyanin because of the formation of hydrogen bonds and van der Waals forces between the anthocyanins and matrix (Kannatt, 2020). The results of this study align with previously reported results (Xu et al, 2023).…”

Preparation and Application of pH-Sensitive Film Containing Anthocyanins Extracted from Lycium ruthenicum Murr.

“…At the same time, the cross-sectional profile showed tiny cracks on the outer surface of the LRMA-containing film, which gradually lengthened. A possible reason for this is that, at low concentrations of LMRA solution, the anthocyanin molecules interacted only with the surface molecules of the solid matrix [ 67 , 68 ]. Upon increasing the strength of the solution, the number of anthocyanin molecules aggregating on the surface of the film increased, and the anthocyanin molecules entered the interior of the film via hydrogen bonding, breaking the original compact spatial structure between ASKG and SPI [ 46 , 53 ].…”