• Mohammadifar, Mohammad Amin
• Mohammadi, Reza
• Kariminejad, Mohaddeseh
• Askari, Fatemeh
• Mortazavian, Amir Mohammad
• Sadeghi, Ehsan
• Taghizadeh, Masoumeh
• Rouhi, Milad

Abstract

This study investigated a novel method of photosensitizer-induced cross-linking (using riboflavin as a sensitizer) to improve the structural and physicochemical properties of gelatin-based edible films with different glycerol concentrations (25% and 50%) during different UV exposure times (2, 4 and 6 h). The films' tensile strength was enhanced significantly for both glycerol concentrations with increasing UV exposure times compared to the control film, so that the highest tensile strength was observed for films with 25% glycerol and 6 h of UV exposure (25%-6 h). The films' tensile strength declined and the elongation at break increased about three times when the glycerol concentration was increased to 50% with 6 h exposure. The photosensitizer-induced cross-linking significantly reduced the films' solubility and permeability. The UV-treated films exhibited very good barrier properties against UV, with zero light transmission at a wavelength of 200 to 350 nm. Moreover, no toxicity was found in any of the films. In addition, Fourier transform infrared spectroscopy and differential scanning calorimetry findings revealed a good interaction between functional groups of riboflavin (as the sensitizer) and gelatin in the 25%-6 h film. Therefore, this new method can be a suitable alternative to chemical methods of cross-linking biopolymers.

Topics

• strength
• permeability
• differential scanning calorimetry
• tensile strength
• toxicity
• Fourier transform infrared spectroscopy