The colours of oils result from included lipochromes that have special colorific qualifications. The most common natural colorants in vegetable oils are alpha and beta carotone , xanthophyll and chlorophyll but the oils gotten of low-quality crude materials and also stored under inanppropriate conditions of temperature , moisture and oxygen , contain natural
Colarants together with oil- inspissating compounds that are formed as a result of oxidative reactions.It is particularly hard to bleach these kinds of oil.
The most common method applied today for bleaching oils is executed through being soaked up of the colorant pigments in oil, phospholpid residues , oxidation materials ,ize metals and soap residues by the absorbents and removal of those absorbents from oil via filtration.
Bleaching soils with high surface activation is applied in this method .This is applied under vacuum , that is to say , in an oxygen – free environment to keep oil away from oxidation and its negative effects because the process of bleaching is carried out under high – temperature (95-100)
As the last word , the process of bleaching has a strong influence in terms of increasing stability of flavour.