SILPAKORN UNIVERSITY SCIENCE AND TECHNOLOGY JOURNAL, Vol 2, No 2 (2008)

Model of Degradation Kinetics for Coconut Oil at Various Heating Temperatures

Wibul Wongpoowarak, Wiwat Pichayakorn, Kwunchit Oungbho, Watcharakorn Boontaweesakul, Siriporn Sirivongmongkol, Prapaporn Boonme

Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat-Yai, Songkhla

Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat-Yai, Songkhla

Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat-Yai, Songkhla

Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat-Yai, Songkhla

Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat-Yai, Songkhla

Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat-Yai, Songkhla


Abstract


This study was aimed to investigate the model of degradation kinetics for coconut oil at various heating temperatures. The oxidative stability of coconut oil at temperature variations between 130 and 200 °C was investigated by UV absorbance measurement. The induction times (time-to-abrupt change) were determined from the curves between the absorbance at 270 nm, related to amount of secondary oxidation products, and time. The model of degradation kinetics was empirically estimated using non-linear regression. From the obtained model, coconut oil degraded via at least two different pathways while being heated, i.e., autocatalysis and first order reactions. This model could describe the entire degradation curve including the induction time behavior of coconut oil at heating temperatures below 150 °C. However, at higher heating temperatures, the other pathways of degradation might occur which could not be explained by the proposed model.

Key Words: Degradation kinetics; Oxidative stability; Induction time; Coconut oil

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