Properties of beeswax–gelatin-based bigels and the influence of hydrogel particle size

The granularity effect is a key factor in many experiments, significantly influencing the properties and performance of materials. This study prepared oleogels and hydrogels using beeswax and gelatin as gelators, respectively. The study examined the effects of hydrogel particle size on the performance of the bigels and the influence of storage conditions on hydrogel particle size. The results indicate that the Fourier Transform Infrared Spectroscopy (FTIR) spectral characteristics of the bigels are predominantly governed by the oleogel component. Differential scanning calorimetry (DSC) analysis further revealed that the bigels began to melt at approximately 37 °C, reached a peak endothermic response at 55 °C, and completed melting at 60 °C, exhibiting more complex and broader thermal behavior than the individual components. As the hydrogel particle size within the bigels decreased, hardness increased by 2.20 times, elastic modulus by 2.23 times, and both storage and loss moduli also rose, indicating enhanced elasticity and energy dissipation. Smaller hydrogel particle sizes improved oil retention capacity, with BG5 exhibiting a 15.73% higher oil retention rate than BG1 under non-freeze-thaw conditions. Freeze-thaw cycles significantly affected hydrogel particle size, with the particle size of BG1 increasing by 38.33 μm and BG5 increasing by only 12.61 μm. • Smaller hydrogel particle size improves the hardness and elasticity of bigels. • Smaller hydrogel particle size enhances the oil retention capacity of bigels. • Freeze-thaw cycles significantly affect the oil retention and hydrogel particle size changes in bigels.