Effect of UV exposure time on the properties of films prepared from biotechnologically derived chicken gelatin

Abstract

Biomaterials (films, foils, fibers, coatings) based on proteins are becoming increasingly important due to the growing applications for which pork and beef gelatins are used. Alternative types of gelatins (poultry or fish), which have not yet been sufficiently tested, represent a high potential. This study looks at the effect of different UV exposure times on chicken gelatin films with added glycerol. The gelatin was prepared using a unique enzymatic hydrolysis process. The quality of the UV-exposed films was compared with gelatin films not exposed to UV light. Radiation-induced crosslinking improved the mechanical and physical properties of the films. The UV crosslinked films are stabilized at a degree of swelling from 700 to 900%; moreover, they extend their dissolution to more than 7 days while maintaining their original shape. In contrast, non-crosslinked films swell and dissolve in water faster. Further, the effect of UV radiation on the water vapor permeability and color of the films was monitored. Water vapor permeability decreased by 2.5 times with increasing crosslinking time for 30% and 40% glycerol content, and the yellowness of the irradiated samples increased with exposure time in the interval from 24 to 28. Using Fourier transform infrared spectroscopy, the differences in the amount of bonding based on irradiation time were analyzed. As a result of crosslinking, the intensity of existing bonds increased. Thermal properties were verified through differential scanning calorimetry and thermogravimetric analysis. The results proved that chicken gelatin is suitable for preparing films in foods and medicine. Applying UV radiation to crosslink gelatin films is an alternative to traditionally used chemical crosslinkers.