Production and characterization of insoluble dietary fiber-based oleogel via capillary force-driven structuring: Influence of water and fiber content.

Abstract

A novel fiber-based oleogel was prepared by capillary force-driven structuring of pomegranate seed meal insoluble dietary fiber (PSMF) in pomegranate seed oil (PSO). The effects of particle fraction (φ) and secondary fluid (water) content (S) on oleogel formation were assessed through microstructural, rheological, textural, and oil loss analyses. Increasing S shifted the system from fluid-like to gel-like behavior, with optimal properties at S = 0.5 and φ = 0.4, yielding the highest yield stress (1286 Pa), greatest hardness (109.44 N), and lowest oil loss. The formulation with S = 0.5 and φ = 0.33 showed textural properties comparable to a commercial spread. In vitro digestion of the selected oleogel increased free fatty acid release versus bulk oil. The optimized oleogel remained structurally stable under temperature changes, while bulk oil showed greater oxidation during 40 days of storage. Oxidation kinetic models successfully predicted changes in oxidation values over storage time.