Bleaching of rapeseed oil

Bijeljenjem se iz ulja uklanjaju prvenstveno pigmenti, klorofili i karotenoidi, ali i fosfolipidi, tragovi metala, hidroperoksidi. Pigmenti su spojevi koji određuju boju ulja i moraju se ukloniti u procesu bijeljenja prvenstveno zbog navike potrošača da su jestiva ulja svijetlo žute boje. Cilj ovoga rada bio je utvrditi utjecaj procesa bijeljenja na udio pigmenata repičinog ulja te na boju ulja. Prema dobivenim rezultatima u ovom radu može se zaključiti da je proces bijeljenja dobro proveden. Udio klorofila se procesom neutralizacije i bijeljenja smanjio na 0,55 mg feofitina a kg-1, što je unutar granica preporučenih literaturom. Udio karotenoida i indeks boje neutralizacijom i bijeljenjem smanjeni su za približno 85% u odnosu na sirovo ulje.Bleaching is primarily used for reducing the amount of pigments of the oil, but also phospholipids, metal traces and hydroperoxides. Pigments are compounds that determine the color of the oil and they must be removed in the process of bleaching primarily because the consumers are used to the fact that edible oils are light yellow. The aim of this study was to determine the effect of the bleaching process on the amount of pigments and, consequently, on the color of the oil. By the results obtained in this final paper one could conclude that processes of neutralization and bleaching were efficient in pigment removal. By those two processes chlorophyll content was reduced at value of 0,55 pheophytin a kg-1 of oil, which is under the upper limit prescribed by the literature. With applied processes the amount of carotenoides and colour index were reduced for about 85% compared with crude rapeseed oil