A. Kamaleldin et La. Appelqvist, VARIATIONS IN THE COMPOSITION OF STEROLS, TOCOPHEROLS AND LIGNANS IN SEED OILS FROM 4 SESAMUM SPECIES, Journal of the American Oil Chemists' Society, 71(2), 1994, pp. 149-156
Seeds from different collections of cultivated Sesamum indicum Linn an
d three related wild species [specifically, S. alatum Thonn., S. radia
tum Schum and Thonn. and S. angustifolium (Oliv.) Engl.] were studied
for their oil contents and fatty acid composition of the total lipids.
The oils from wild seeds were characterized by higher percentages of
unsaponifiables (4.9, 2.6 and 3.7%, respectively) compared to S. indic
um (1.4-1.8%), mainly due to their high contents of lignans. Total ste
rols accounted for ca 40, 22, 20 and 16% of the unsaponifiables of the
four species, respectively. The four species were different in the re
lative percentages of the three sterol fractions (the desmethyl, monom
ethyl and dimethyl sterols) and in the percentage composition of each
fraction. Campesterol, stigmasterol, sitosterol and Delta(5)-avenaster
ol were the major desmethyl sterols, whereas obtusifoliol, gramisterol
, cycloeucalenol and citrostandienol were the major monomethyl sterols
, and alpha-amyrin, beta-amyrin, cycloartenol and 24 methylene cycloar
tanol were the main dimethyl sterols in all species. Differences were
also observed among the four species in sterol patterns of the free st
erols compared to the sterol esters. Sesamum alatum contained less toc
opherols (210-320 mg/kg oil), and S. radiatum and S. angustifolium con
tained more tocopherols (ca 750 and 800 mg/kg oil, respectively) than
did S. indicum (490-680 mg/kg oil). The four species were comparable i
n tocopherol composition, with gamma-tocopherol representing 96-99% of
the total tocopherols. The four species varied widely in the identity
and levels of the different lignans. The percentages of these lignans
in the oils of S. indicum were sesamin (0.55%) and sesamolin (0.50%).
Sesamum alatum showed 1.37% of 2-episesalatin and minor amounts of se
samin and sesamolin (0.01% each). Sesamum radiatum was rich in sesamin
(2.40%) and contained minor amounts of sesamolin (0.02%), where S. an
gustifolium was rich in sesangolin (3.15%) and also contained consider
able amounts of sesamin (0.32%) and sesamolin (0.16%).