Degradation of Gamma-oryzanol in Rice Bran Oil during Heating : An Analysis Using Derivative UV-spectrophotometry
Pramote Khuwijitjaru, Nichchima Taengtieng, Suchaya Changprasit
Gamma-oryzanol, a group of ferulic acid esters of phytosterols and triterpene alcohols, has been reported to exhibit antioxidant activity and other health beneficial properties. In this study, the degradation of gamma-oryzanol in rice bran oil during the heat treatment was investigated. The quantitative analysis of the gamma-oryzanol in rice bran oil was performed by second order derivative UV-spectrophotometry. The degradation kinetics was described by the first-order reaction model and degradation rate constants were 0.0089, 0.0315 and 0.0763 at 120, 150 and 200ºC, respectively. Temperature dependence of the rate constant obeyed Arrhenius relationship, and activation energy was calculated to be 40.76 kJ/mol.
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