Oleogel formation based on natural insoluble soybean fiber using capillary force: A novel strategy and application

Insoluble dietary fibers can be used as oleogelators to form oleogels via molecular self-assembly following chemical modification. However, the limitations of traditional chemical modifications and oleogel preparation methods significantly restrict their practical application. This study proposed a novel method to directly form edible oleogels using natural soybean insoluble fiber particles as oil-forming agents and water as a secondary fluid via the capillary suspension force between particles. The results showed that when the particle fraction was 15 % and the secondary fluid content was 0.2, a strong capillary suspension force could be formed to maintain the oil holding capacity of oleogels. The sedimentation coefficient analysis suggested that adding particles and secondary fluids significantly affected the oleogel stability. The polarity of the oils, as well as the ionic strength and pH of the secondary fluids, influenced the rheological properties of oleogels, which correlated with the interfacial tension between the secondary fluids and oils. Moreover, the stable oleogels showed their potential as excellent solid fat substitutes in the preparation of breads (specific volume = 2.029 ± 0.114 cm³/g, weight loss = 12.2 ± 2.6 %, and hardness = 3.321 ± 0.055 N). This study highlighted that insoluble dietary fiber can form oleogels via capillary suspension, which is a relatively rapid and simple strategy. Additionally, it provided a solid foundation for the comprehensive utilization of soybean processing byproducts and the transformation of traditional food-specific oils and fats.