REACTION OF CAROTENES IN PALM OIL WITH ACID

Carotenes in palm oil reacted with strong acid under nonaqueous condit ions to produce blue-green cations that initially absorbed with a broa d maximum at approximately 900 mn. These cations were postulated to be formed from the protonation of the alpha- and beta-carotene at the se venth carbon atom, with the charge delocalized between the 8 and 9 con jugated double bonds. They were unstable at room temperature and may, by isomerization and oxidization, form carotenoid compounds with short er conjugation. The resulting carotenoids can be protonated further to form cations, which absorbed between 500-900 mn, with lambda(max) of approximately 800 mn. The transient blue-green color observed in parti ally bleached palm oil is likely due to the presence of these cations.