This study aimed to understand the effect of fatty acid composition and viscosity of vegetable oils on network formation mechanism and physical properties of oleogels. To this purpose, 12 oleogels were prepared, by choosing 6 seed oils and two waxes, at a fixed oleogelator concentration (6%). The modified Avrami model correctly describes the crystallization profile (R2 > 0.98) and the oil type did not affect the Avrami index that ranged from 1.00 to 1.43. Independently from oleogelator, rice and hemp seed oils followed a 3-D network formation mechanism, while almond oil a 2-D mechanism. The strength and yield stress of carnauba wax oleogels increased with increasing saturated fatty acid amount, while in beeswax-based oleogels a more interconnected structure was associated with the length of the saturated fatty acid chain. Thus, the oleogels formation mechanism was closely related to the chemical composition of the solvent, even in highly monounsaturated or polyunsaturated oils.
Keywords: Fatty acids; Modified Avrami model; Oil binding capacity; Oil structuration; Rheology; Thermal behaviour.
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