The fabrication, microstructure, rheological properties and interactions of soft solid oleogels of hazelnut oil body

Abstract

Trans and saturated fatty acids in dietary solid fats have negative effects on human health, such as chronic diseases, making the development of a fat substitute an urgent matter. The plant derived oil body-hazelnut oil body (HOB) as the oil droplets, and the hydrogel formed by xanthan gum (XG) and type B gelatin (GEL) as the outer layer were used to encapsulate HOB and construct the oleogel. The OBC, microstructure, and rheological results indicated that the XG-GEL formed a sponge-like, tightly packed three-dimensional network structure on the surface of HOB, effectively preventing oil leakage. The hazelnut oil body oleogel exhibited 100% OBC, excellent deformation resistance, and thixotropic recovery ability. FTIR spectroscopy results revealed that changes in the amide I, II, III, and A bands indicated the formation of hydrogen bonds, with pronounced hydrogen bonding occurring between the amino/hydroxyl groups of HOB and the hydroxyl/carboxyl groups of XG-GEL. Raman spectroscopy results suggested that HOB-XG-GEL likely exhibited stronger hydrophobic interactions, while XG-GEL had no significant impact on the unsaturation level, membrane composition, or lipid acyl chain disorder of HOB. XRD results showed a single broad diffraction peak at 2θ = 19.6°, corresponding to π-π stacking interactions between HOB and XG-GEL. Interfacial characterization and zeta potential results demonstrated that HOB-XG-GEL had stronger surface activity and electrostatic repulsion. XRD and DSC results confirmed that the hazelnut oil body oleogel displayed an amorphous structure and good thermal stability. This study provides a new strategy for fabricating oil bodies to produce edible oleogels instead of solid fats.