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

✍ Scribed by Pramote Khuwijitjaru; Thippawan Yuenyong; Rungnaphar Pongsawatmanit; Shuji Adachi

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 134 KB
• Volume: 113
• Category: Article
• ISSN: 1438-7697
• DOI: 10.1002/ejlt.201000485

✦ Synopsis

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.