Characterization of gelatin films functionalized with silver nanoparticles or polysorbate 20 as UV–vis light controllers

Abstract

Given its versatility as a biopolymer, fish gelatin has numerous industrial applications and there is significant interest in modifying its properties to broaden its potential uses. The primary aim of our study is to investigate the individual effects of two additive agents on rheological, thermomechanical, and physicochemical properties of fish gelatin films. The selected additive agents were: 1) silver nanoparticles [0.61, 0.91 and 1.22 nmolAgNP•m−2] and 2) polysorbate 20. Rheological and physicochemical characterizations of the fish gelatin filmogenic solutions were performed. Rheological results showed that both the addition of silver nanoparticles and polysorbate 20 generate similar results such as non-Newtonian behavior at 40 °C and a cutting speed of 1–100 1/s; as well as liquid film-forming solutions in the angular frequency range between 1 and 600 rad/s. However, substantial differences were found in the effects generated on the thermomechanical properties, physicochemical properties, and UV-Vis barrier effect. The increase in content of silver nanoparticles to 1.22 nmolAgNP•m−2 generated a higher increase in glass transition temperature and modulus of elasticity compared to the polysorbate treatment. In contrast, the incorporation of polysorbate leads to higher opacity than the incorporation of silver nanoparticles; thus a better barrier effect against visible and UV light in the range from 300 to 1000 nm. In conclusion, the results obtained indicate that the incorporation of silver nanoparticles or polysorbate manages to modify the functionality of fish gelatin films, expanding their potential applications as packaging materials.