Examination of the stability of vegetable oils in the course of use and storage
1992
Kemeny, T. | Weinbrenner, Zs. | Kolloros, J. | Jeranek, M. (Novenyolaj- es Mososzeripari Kut. Int. (Hungary))
Sunflower and rape oil were stored in 1-litre PVC flacons and 200-litre plastic lined metal barrels at 15-20 C/degrees/. The samples were analyzed every month for a year, always a new flacon, with classical and instrumental methods. The examinations covered the peroxide number, anizidin number, the UV light-absorption at 232 and 268 nm, the total amount of polar compounds (measured by column chromatography), the acid number, and the triglyceride, polymer and tocoferol content of the oil (measured by high capacity liquid chromatography). It was found that sunflower oils produced by conventional technology degraded to a similar extent as those produced by physical disacidification. The decomposition product content still acceptable from a nutritional point of view was only exceeded in either of the two oils after 4-6 h of heat treatment at 190 C/degrees/. It was also found that the degradation of the oil was of much lower extent in the case of continuous frying than when frying was repeatedly discontinued and restarted
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