Abstract:
The present study was carried out to investigate t
he effect of various refining
processes’ conditions on conjugated dienes in soybe
an oil. Conjugated dienes contents of
soybean oil were found to undergo reduction in neut
ralization and bleaching steps while
being increased in deodorization. It was observed t
hat alkali refining (neutralization)
through 12 and 14 °Bé, bleaching with either acid ac
tivated clay or a mixture of acid
activated clay plus activated carbon at 110 ̊C along
with deodorization at 220 ̊C and at 4
or 8 mbar had the highest effect on reduction of co
njugated dienes in soybean oil.
Conjugated dienes were in good correlation with per
oxide value, free fatty acids,
Totox
value and as well with
p
-anisidine value in each step. Overall, alkali refi
ning proved to be
the most effective step in reduction of conjugated
dienes, free fatty acids and oxidative
stability index. Peroxide value,
p
-anisidine and
Totox
values changed during refining and
got significantly decreased in deodorization.
Keywords:
Conjugated dienoic acid, Edible oil, Oil processing
, Peroxide value,
p
-Anisidine value.
