Different formulations and crystallising conditions were employed to vary the bulk phase structuring of oleogels. The oleogels were formed only at monoacylglycerol:native phytosterol (MAG:NPS) ratios of 10:0, 7:3 and 5:5. NPS co-crystallised with MAG in the oleogel mixtures and influenced the growth of lipidic crystal network. Faster cooling rates caused smaller crystals whereas thermal history affected the rigidity of oleogel samples. The oleogel samples were whipped and characterised for whipping time, foam overrun, microstructure, rheology and half-life of foam. The whipped oleogels were structured by layer(s) of lipidic crystals surrounding the air bubbles, which had non-spherical shapes and rough textures. The whipping time was remarkably reduced by 80% in the oleogel samples containing smaller lipidic crystals. All whippable oleogel samples had similar foam overrun values and extremely stable against foam collapse. The obtained oil foams exhibited liquid-like behaviour at low frequency as measured by the frequency sweep test.
Keywords: Lipidic crystal size; Monoacylglycerol; Native phytosterols; Oil foams; Oleogels; Whippability.
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