BLEACHING
In the bleaching process, which is common in both physical and alkali increments, hot oil (about 100 [deg.] C.) is slurried with acid-activated bleaching soil, calcium montmorillonite or naturally hydrated aluminum silica. In this process, the aim is to remove residual soaps and phospholipids, as well as residual color soaps, trace metals, and oxidation products after washing the neutralized structures. The bleaching process consists of vacuum bleaching, vacuum cleaning, bleaching, pretreatment/conditioning (acid).
BLEACHING REACTIONS
The two main reactions commonly found in all vegetable oils are as follows:
DEGRADATION OF HYDROPEROXIDES
During bleaching, the hydroperoxides are decomposed to form oxidized triacylglycerols containing keto and hydroxy functions. After bleaching, the peroxide value must be zero or close to zero.
DEHYDRATION OF ALCOHOLS
Hydroxy acids formed from hydroperoxide are subjected to partial dehydration by soil catalysis. Since the function is in a position of alkyl, the formation of conjugated dienes from oleic acid hydroperoxides is observed due to the formation of conjugated trienes from linoleic acid hydroperoxides.
