Partial replacement of fat with oat and wheat bran gels: Optimization study based on rheological and textural properties

- Oat and wheat bran gels were examined as fat replacers.
- Optimization study based on rheological and textural properties was conducted.
- Parameters of bran gel preparation can be successfully optimized using RSM.
- Optimized bran gel formulations mimicked fat strength and spreadability.

Wheat and oat brans, by-products of grain processing, were investigated in the form of gels for partial replacement of fat. The objective of this study was to determine the optimal bran concentration, homogenization temperature and time to create bran gel/vegetable fat model systems (BGF model systems) with similar dynamic rheological properties and spreadability to the control fat. The response surface methodology approach based on Derringer's desirability function was applied, and the highest overall desirability was accomplished with the following parameters: 22.0 g/100 g of bran concentration, 11.7 min homogenization time and 83.2 °C homogenization temperature (for the wheat bran) and bran concentration of 22.0 g/100 g, homogenization time of 10.0 min and homogenization temperature of 95.0 °C (for the oat bran). Oat bran required higher homogenization temperature since its structure was mostly built upon starch gelatinization, while wheat bran was capable of making gels under lower temperatures due to fibre cross-linking.