Photosensitizer-induced cross-linking: A novel approach for improvement of physicochemical and structural properties of gelatin edible films

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.

A Novel Sodium Alginate-Carnauba Wax Film Containing Calcium Ascorbate: Structural Properties and Preservative Effect on Fresh-Cut Apples

“…Environmental and renewable edible film has become a new and attractive material in the field of food packaging [ 3 ]. Edible film, which is formed by edible natural polymer materials as raw materials through the interaction of different molecules, has a porous network structure and a certain packaging protection function [ 4 ]. According to different raw materials, it can be divided into polysaccharides, proteins, lipids and composite edible films [ 5 ].…”

Formulation and Characterization of Edible Films Based on Organic Mucilage from Mexican Opuntia ficus-indica

“…In the last several years, interest in the production of edible films has increased because they present a series of advantages, such as prolonging the shelf life of foods and reducing the use of plastics. Therefore, many film-forming materials such as starch [1][2][3][4], gelatin [5], chitosan [6][7][8], cellulose [9], carboxymethyl cellulose [10], methylcellulose [11], pectin [12,13], agar [14], alginate [15,16], carrageenan [16], zein [17], etc., have been used. Mucilage from Mexican Opuntia ficus-indica is suitable for large-scale production due to its abundance in Mexico, low cost, nontoxicity, biodegradability, biocompatibility, film-forming capacity, and renewability.…”

Antioxidant and antibacterial starch-based edible films composed of eugenol/gelatin microspheres

“…MTT activity assays were carried out to evaluate the effect of composite films on cell death and cell proliferation. 24 Density of 5000 pcs per hole HepG2 cells were gently seeded on the 96-well cell culture plate and fed with 200 mL of culture medium. The films (5 mm  5 mm) were immersed in the medium containing cells and incubated in a humidified atmosphere of air and 5% CO 2 at 37 1C for 24 h. After each interval, the films were carefully removed and cells were treated with 20 mL MTT solution for 4 h again.…”