Effect of photochemical UV/riboflavin‐mediated cross‐links on different properties of fish gelatin films

Abstract The use of riboflavin as photosensitizer in the UV irradiation induced cross‐linking process was studied to improve the properties of fish gelatin (FG) films. In the UV irradiation, the fluorescence spectroscopy results showed that cross‐linking occurred in the film at a riboflavin charge of 0.1% or higher and the viscosity of the FG solution increased as the riboflavin charge increased. The water contact angel of the fish gelatin film with the riboflavin mediated UV irradiation (RmUV) was significantly improved compared with the control FG films at 60 s. Moreover, compared with control FG films, water vapor absorption and water solubility of the RmUV radiated FG films both decreased. The tensile strength and Young's modulus of the RmUV radiated FG films were significantly higher than those of the control FG films whatever in dry or wet state. Based on the above results, the UV/riboflavin irradiation is a potential effective process to improve the performance of FG films. Practical applications In the past decades, the extensive use of plastic packaging has led to increased concerns on plastic waste generated in daily life due to its nonbiodegradable and nonrenewable nature. For that reason, a variety of bio‐based materials including fish gelatin have been developed as environmentally friendly alternatives. The aim of this paper is to explore the potential application of the fish gelatin film with the riboflavin mediated UV irradiation (RmUV) in mainly food‐contacted packing material field. The use of riboflavin as photosensitizer in the UV irradiation induced cross‐linking in fish gelatin (FG) films, which subsequently improved the water resistance and strength properties of FG films. The findings in this study may serve as a platform to improve fish gelatin film performance and potentially extend applications of edible fish gelatin films in food industry.