Oxidation of Olive Oil under Still Air
2005
Kanavouras, A. | Cert, A. | Hernandez, R. J.
This work was conducted to analyse the effect of different exposed areas/mass ratios on oil oxidation. Different volumes of the triacylglycerol portion of purified olive oil were placed in glass vials with the same air-exposed area, and stored at 38°C in the dark under still air. The oxidation process was evaluated by determining the peroxide index, K₂₃₂ and K₂₇₀ extinction coefficients, fatty acid composition, polar compounds (PCs) and composition of triacylglycerols over time. Substantial differences in the oxidation rate as a function of the air-exposed area to triacylglycerol fraction-mass ratio were observed. The peroxide index exponential increase with time was correlated to the air-exposed area/triacylglycerol fraction mass ratio and the oxidation induction period. Less oxidation derived by-products per gram of triacylglycerols were observed for smaller air-exposed area/triacylglycerol fraction mass ratios. The oxidation process followed an apparent first order chemical reaction. Correlations of the evolution patterns among the various oxidation by-products were also reported.
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