Abstract: Cinnamic acid based rice bran oil organogel, prepared with rice bran oil as solvent and cinnamic acid as gelling agent, was characterized by X-ray diffraction (XRD), fluorescence microscope and rheometer for the analysis of rheological behavior and morphological structure. The results showed that the oil binding capacity and melting point gradually increased with cinnamic acid concentration up to 10%, and then did not significantly increase at higher cinnamic acid concentrations (P > 0.05); the oil binding capacity rapidly increased to 93.62% with temperature up to 85 ℃, and the melting point also reached a high level. The two parameters remain at a high level with increasing cooling temperature from 0 to 5 ℃, and then significantly decreased to 93% at higher cooling temperatures (P < 0.05). Rheological analysis showed that the organogel with 10% of cinnamic acid formed by heating at 85 ℃ and cooling at 5 ℃ was a pseudoplastic fluid and that the relationship between apparent viscosity and shear rate was fitted with the power law equation. Moreover, in the experimental range of frequency sweeping, the storage modulus (G′) was obviously higher than the loss modulus (G′′), indicating that the organogel had a compact structure. Under the microscope, tiny and evenly distributed crystal structures with polymorphism were observed and the main crystal structure types were β and β’.

Key words: rice bran oil, cinnamic acid, organogel, rheological behavior, morphological structure