|
The effects of oil refining processes-degumming, alkali-refining, bleaching and deodorizing-on oil characteristics and oxidation stability of sesame oil were investigated. The colors (L, a, b) of samples were markedly changed and their peroxide and acid values were decreased, while the other characteristics of samples were not changed during refining stages. The L values of alkali-refined, bleached and deodorized sesame oils were largely decreased and their a values were increased due to browning reaction during the storage at 70℃. The colors of crude and degmmed sesame oils were very stable and their peroxide, free fatty acid and conjugated dienoic acid values were slowly increased. Volatile carbonyl compounds formed by oxidation were increased during the storage at 70℃. The results indicated that refining processes did not affect the sesame oil characteristics but decreased the oxidation stability of sesame oil.
|