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Effects of ferric chloride on thermal degradation of γ‐oryzanol and oxidation of rice bran oil
Author(s) -
Khuwijitjaru Pramote,
Yuenyong Thippawan,
Pongsawatmanit Rungnaphar,
Adachi Shuji
Publication year - 2011
Publication title -
european journal of lipid science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 94
eISSN - 1438-9312
pISSN - 1438-7697
DOI - 10.1002/ejlt.201000485
Subject(s) - ferric , chemistry , peroxide value , chloride , rice bran oil , bran , degradation (telecommunications) , lipid oxidation , antioxidant , food science , reaction rate constant , nuclear chemistry , kinetics , organic chemistry , raw material , telecommunications , computer science , physics , quantum mechanics
The kinetics of γ‐oryzanol degradation in antioxidant‐stripped rice bran oil were investigated at 180°C 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 γ‐oryzanol and the extent of lipid oxidation (peroxide value and p ‐anisidine value). It was found that the losses of γ‐oryzanol and its four components (cycloartenyl ferulate, 24‐methylene cycloartanyl ferulate, campesteryl ferulate, and β‐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 γ‐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 γ‐oryzanol and lipid oxidation.