C. Demir et M. Cetin, Determination of tocopherols, fatty acids and oxidative stability of pecan, walnut and sunflower oils, DEUT LEBENS, 95(7), 1999, pp. 278-282
Pecan and walnut oils were extracted by pressing and solvent extraction met
hods. Fatty acids and tocopherols of oils were determined and oxidation sta
bility of oils was investigated. The results were compared with sunflower o
il. Determination of fatty acids was performed by gas chromatography (GG).
It was observed that composition of unsaturated fatty acids is high in waln
ut oil. Tocopherols were determined in oils by high performance liquid chro
matography HPLC. Only gamma-tocopherol was found in pecan oil, alpha-, gamm
a- and delta-tocopherols in walnut oil, and alpha- and gamma-tocopherols in
sunflower oil. It was observed that more amounts of tocopherols are obtain
ed by pressing. Oxidative stability of oils was followed at 100 degrees C b
y determining the peroxide value. Walnut oil oxidizes faster than pecan and
sunflower oils and the oxidative stability is high in oils obtained by sol
vent extraction.