Journal of the American Oil Chemists' Society

, Volume 86, Issue 2, pp 149–156 | Cite as

Degradation and Nutritional Quality Changes of Oil During Frying

  • Felix A. Aladedunye
  • Roman PrzybylskiEmail author
Original Paper


The changes in regular canola oil as affected by frying temperature were studied. French fries were fried intermittently in canola oil that was heated for 7 h daily over seven consecutive days. Thermo-oxidative alterations of the oil heated at 185 ± 5 or 215 ± 5 °C were measured by total polar components (TPC), anisidine value (AV), color components formation, and changes in fatty acid composition and tocopherols. Results showed that TPC, AV, color and trans fatty acid content increased significantly (P < 0.05) as a function of frying temperature and time. The oil polyunsaturated fatty acids (PUFA) decreased in direct proportion to frying temperature and time. After 7 days of frying, the amount of PUFA was reduced by half and the trans isomers contribution increased 2.5 times during frying at 215 °C. Of the parameters assessed, total polar component and color had the highest correlation, with correlation coefficients of 0.9650 and 0.9302 for frying at 215 and 185 °C, respectively. TPC formation correlated inversely with the reduction of tocopherols.


Canola oil Frying performance Total polar component Anisidine value Color Frying temperature Tocopherols French fries Fatty acids 



Financial support from Canola Council of Canada and Alberta Value Added Corporation for this research are gratefully acknowledged.


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Copyright information

© AOCS 2008

Authors and Affiliations

  1. 1.Department of Chemistry and BiochemistryUniversity of LethbridgeLethbridgeCanada

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