Effect of Tribute citrus essential oil nanoemulsion-loaded gelatin on the gel behavior and gelation surface morphologies

Abstract

Nanoemulsions (NEs) loaded with Tribute citrus essential oil (EO) were prepared using Tween-80. Five different concentrations (0, 1, 3, 5, and 7%) were then incorporated into a gelatin base. The droplet size, PDI, and zeta potential of the NE after EO loading were found to be 241.4 nm, 0.288, and −21.8 mV, respectively. The relationship between the NE and gelatin was examined by measuring the gelation behavior, water mobility, and gelatin structure. As the NE concentration increased, gel properties such as strength, hardness, springiness, adhesiveness, cohesiveness, gumminess, chewiness, and kgel declined. Gelling and melting temperatures were higher after the addition of varying amounts of NE compared with the control. Hydrogen bonding between NEs and gelatin interfered with the formation of a triple helix, as shown by multi-spectroscopic techniques including Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Atomic force microscopy (AFM) revealed that higher NE contents resulted in greater aggregation in the gelatin. These results provide insight into the use of gelatin in EO delivery and describe the basic interaction between EO and gelatin and the resultant gelation behavior in the delivery system.