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Reaction of carotenes in palm oil with acid
Author(s) -
Liew K. Y.,
Nordin M. R.,
Goh L. S.
Publication year - 1994
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02638057
Subject(s) - protonation , isomerization , palm oil , chemistry , delocalized electron , double bond , conjugated system , photochemistry , carotenoid , pigment , carbon atom , carbon fibers , carotene , organic chemistry , ion , materials science , ring (chemistry) , food science , polymer , composite number , composite material , catalysis
Carotenes in palm oil reacted with strong acid under nonaqueous conditions to produce blue‐green cations that initially absorbed with a broad maximum at approximately 900 nm. These cations were postulated to be formed from the protonation of the α‐ and β‐carotene at the seventh carbon atom, with the charge delocalized between the 8 and 9 conjugated double bonds. They were unstable at room temperature and may, by isomerization and oxidization, form carotenoid compounds with shorter conjugation. The resulting carotenoids can be protonated further to form cations, which absorbed between 500–900 nm, with γ max of approximately 800 nm. The transient blue‐green color observed in partially bleached palm oil is likely due to the presence of these cations.