Effect of lipid oxidation on dough bleaching

The effect of lipid composition and oxidation on dough bleaching has been d etermined. At > 2.25% (flour basis), pure linoleic acid was very efficient in degrading beta -carotene in dough, unlike colza, corn, peanut, soy, or s unflower oil, which were mainly characterized by different polyunsaturated fatty acids content. In a very oxidized state, as determined by a peroxide index of >15 meq/kg of oil, sunflower oil (rich in polyunsaturated fatty ac ids) had a major bleaching activity on beta -carotene when compared with co lza oil (less polyunsaturated), especially in combination with long mixing times. A combination of lipase (815 U), slightly oxidized oil (peroxide ind ex of 2-5 meq/kg of oil), and linoleic acid (90 mg/100 g of flour) signific antly degraded flour pigments (P < 0.05).