The
content of phyto
sterol oxidation product
s wa
s determined in
sample
s of crude vegetable oil
s:peanut,
sunflower, maize, palm nut, and lampante olive oil
s that were intended for refining and notfor direct con
sumption. The 7
![](/image<font color=)
s/gifchar
s/alpha.gif" BORDER=0>- and 7
![](/image<font color=)
s/gifchar
s/beta2.gif" BORDER=0 ALIGN="middle">-hydroxy derivative
s of
![](/image<font color=)
s/gifchar
s/beta2.gif" BORDER=0 ALIGN="middle">-
sito
sterol,
stigma
sterol, andcampe
sterol and the 7-keto-
![](/image<font color=)
s/gifchar
s/beta2.gif" BORDER=0 ALIGN="middle">-
sito
sterol were the principal phyto
sterol oxide
s found in almo
st all ofthe oil
s analyzed. In
some oil
s, the epoxy and dihydroxy derivative
s of
![](/image<font color=)
s/gifchar
s/beta2.gif" BORDER=0 ALIGN="middle">-
sito
sterol were al
so foundat very low level
s. The highe
st total concentration
s of phyto
sterol oxide
s, ranging from 4.5 to 67.5and from 4.1 to 60.1 ppm, were found in
sunflower and maize oil
s, re
spectively. Lower concentration
swere pre
sent in the peanut oil
s, 2.7-9.6 ppm, and in the palm nut oil, 5.5 ppm, wherea
s in the lampanteolive oil
s, only three
sample
s of the
six analyzed contained a low concentration (1.5-2.5 ppm) ofoxyphyto
sterol
s. No detectable level
s of phyto
sterol oxide
s were found in the
sample
s of palm andcoconut oil
s. Bleaching experiment
s were carried out on a
sample of
sunflower oil at 80
![](/image<font color=)
s/entitie
s/deg.gif">C for 1 hwith 1 and 2% of both acidic and neutral earth
s. The bleaching cau
sed a reduction of thehydroxyphyto
sterol with partial formation of
steroidal hydrocarbon
s with three double bond
s in thering
sy
stem at the 2-, 4-, and 6-po
sition
s (
steratriene
s). The
same
sunflower oil wa
s deodorized at180
![](/image<font color=)
s/entitie
s/deg.gif">C under vacuum for 1 h, and no dehydration product
s were formed with a complete recoveryof the hydroxyphyto
sterol
s. A bleaching te
st with acidic earth
s wa
s carried out al
so with an extravirgin olive oil fortified with 7-keto-chole
sterol, dihydroxychole
sterol, and
![](/image<font color=)
s/gifchar
s/alpha.gif" BORDER=0>-epoxy-chole
sterol. Therewa
s no formation of
steratriene
s from the
se compound
s, but dihydroxychole
sterol underwentcon
siderable decompo
sition and
![](/image<font color=)
s/gifchar
s/alpha.gif" BORDER=0>-epoxychole
sterol underwent ring opening with formation of thedihydroxy derivative, wherea
s 7-ketochole
sterol wa
s rather
stableKeyword
s: Phyto
sterol oxide
s; chole
sterol oxide
s; vegetable oil
s;
steroidal hydrocarbon
s;
steradiene
s;
steratriene
s; refined oil
s; bleaching; deodorization; ga
s chromatography-ma
ss spectrometry