Effects of ferric chloride on thermal degradation of γ‐oryzanol and oxidation of rice bran oil

Abstract

The kinetics of g-oryzanol degradation in antioxidant-stripped rice bran oil were investigated at 1808C for 50 h. Ferric chloride was added to the oil at different concentrations (0, 2.5, 5.0, and 7.5 mg/kg-oil) to determine the degradation reaction rate of g-oryzanol and the extent of lipid oxidation (peroxide value and p-anisidine value). It was found that the losses of g-oryzanol and its four components (cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, campesteryl ferulate, and b-sitosteryl ferulate) could be described by a first-order kinetics model. The degradation rate constant, k, linearly increased ( p < 0.05) with the ferric chloride concentration, and increased about 1.5 times when 7.5 mg/kg-oil ferric chloride was added. Ferric chloride addition also accelerated the lipid oxidation of rice bran oil significantly ( p < 0.05).Practical applications: This paper describes the kinetic analysis of the degradation of g-oryzanol, a major phytochemical in rice bran oil, at its frying temperature. The results indicated that iron in the form of ferric chloride accelerated both the degradation of g-oryzanol and lipid oxidation.

An Insight into the Thermal Degradation Pathway of γ-Oryzanol and the Effect on the Oxidative Stability of Oil

“…γ-Oryzanol and its components exhibited conformity to the first-order kinetic model at different thermal treatment temperatures ( R 2 > 0.9) (Table S1). Similar observations have been documented in previous studies, which found that the degradation of γ-oryzanol during heating followed first-order kinetics. , …”

“…Similar observations have been documented in previous studies, which found that the degradation of γ-oryzanol during heating followed first-order kinetics. 11,35 According to the results shown in Table 2, it can be observed that with increasing temperature, the thermal degradation rate constant (K) of γ-oryzanol and its four components increased while the half-life (t 1/2 ) decreased. These results indicated that higher temperatures have a greater impact on the stability of γ-oryzanol.…”

Effect of Transition Metal Ions on the B Ring Oxidation of Sterols and their Kinetics in Oil-in-Water Emulsions

“…Khuwijitjaru, P. et al . found that the loss of γ-oryzanol and its four components (cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, campesteryl ferulate, and b-sitosteryl ferulate) could be described by a first-order kinetics model 18 . Similarly, Castaneda, E. J. L. et al .…”