Influence of natamycin loading on the performance of transglutaminase-induced crosslinked gelatin composite films

We investigated the effect of natamycin on the physicochemical properties of crosslinked gelatin films. Natamycin decreased the tensile strength, elongation at break and water vapour barrier of crosslinked gelatin films. The thermal stability of the crosslinked gelatin films varied considerably with natamycin amount. The crosslinked films gradually turned yellow-green in colour with increasing natamycin content. The aforementioned different influences were associated with the altered microstructure and crystallinity of the crosslinked films induced by increasing natamycin amounts. The performance changes in the films could be attributed to the increase in natamycin, resulting in enhanced natamycin crystallinity, which was confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. Moreover, the crosslinking reaction could confer resistance to damage in TGase-induced aggregation caused by natamycin crystallinity. Therefore, the findings in this paper will facilitate the development of gelatin-based food-contact film materials and provide theoretical direction for the packing industry.