Physical, mechanical and antioxidant properties of chicken skin gelatin films incorporated with virgin coconut oil

Abstract

This study aimed to determine the physical, mechanical, and antioxidant properties of chicken skin gelatin films incorporated with virgin coconut oil (VCO). Prepared chicken skin gelatin films at different VCO concentrations (0–30%) were characterized for their physical (water vapor permeability and light transmission), mechanical (tensile strength, elongation at break), and antioxidant (DPPH scavenging activity and total phenolic content) properties. The tensile strength and elongation at the film's break showed a decreasing and increasing trend with the increase of VCO concentration. The water vapor permeability of films showed no significant difference as the added oil concentration increased. In addition, the films with VCO added showed a good light barrier with a lower light transmission value at a high oil concentration. The incorporation of oil in gelatin films decreases the glass transition temperature (Tg) with the increasing amount of oil. Furthermore, the film's microstructure became rougher and more discontinuous with the addition of oil percentage. The increasing VCO concentration also enhanced the intensity of the Amide A, Amide I, Amide II, and Amide III functional groups. DPPH scavenging activity and total phenolic content in films also increased with VCO concentration. Thus, these results revealed that VCO could be incorporated with gelatin film to make active film packaging or edible film packaging for some food applications for protein-rich food, such as meat or edible packaging for primary packaging.