30
L. Yang et al. / Chemistry and Physics of Lipids 119 (2002) 23Á31
/
leic Acid Research, vol. 1. AOCS Press, Champaign, IL,
USA, pp. 354Á368.
Eulitz, K., Yurawecz, M.P., Ku, Y., 1999. The oxidation of
conjugated linoleic acid. In: Yurawecz, M.P., Mossoba,
M.M., Kramer, J.K.G., Pariza, M.W., Nelson, G.J. (Eds.),
Advances in Conjugated Linoleic Acid Research, vol. 1.
the double bond at position 9 migrates towards
position 10 to produce 9c,11t-18:2, and the double
bond at position 12 migrates towards position 11
to form 9c,11t-18:2.
/
The present study examined the effects of
temperature and dehydration reagents on the
CLA production and when ricinoleic acid and
linoleic acid were used as starting materials. The
results clearly demonstrated that dehydration of
MMOE and alkali isomerization of linoleic acid
produced different CLA profiles. It is premature
to assess merits of one method over another at the
present time because the information on biological
activities of each CLA isomer is still limited. Some
evidences suggested that 9c,11t-18:2 was the active
isomer (Ip et al., 1991; Knekt et al., 1996) while
several recent reports showed that 10c,12t-18:2
was biologically more potent than 9c,11t-18:2
AOCS Press, Champaign, IL, USA, pp. 55Á63.
/
Griinari, J.M., Bauman, D.E., 1999. Biosynthesis of conjugated
linoleic acid and its incorporation into meat and milk in
ruminants. In: Yurawecz, M.P., Mossoba, M.M., Kramer,
J.K.G., Pariza, M.W., Nelson, G.J. (Eds.), Advances in
Conjugated Linoleic Acid Research, vol. 1. AOCS Press,
Champaign, IL, USA, pp. 180Á200.
/
Griinari, J.E., Corl, B.A., Lacy, S.H., Chouinard, P.Y.,
Nurmela, K.V., Bauman, D.E., 2000. Conjugated linoleic
acid is synthesized endogenously in lactating dairy cows by
delta(9)-desturase. J. Nutr. 130, 2285Á2291.
/
Ha, Y.L., Grimm, N.K., Pariza, M.W., 1989. Newly recognized
anticarcinogenic fatty acids: identification and quantifica-
tion in natural and processed cheeses. J. Agric. Food Chem.
3
7, 75Á81.
/
(
Leung and Liu, 2000; Lin et al., 2001; Park et
Ha, Y.L., Storkson, J., Pariza, M.W., 1990. Inhibition of
benz(a)pyrene-induced mouse forstomach neoplasia by
conjugated dienoic derivatives of linoleic acid. Cancer Res.
al., 1999). If 9c,11t-18:2 were the only active
isomer, dehydration of MMOE catalyzed by
KOH would be a preferred method to produce
CLA. If 9c,11t-18:2 and 9c,11t-18:2 were both
biologically active, alkali isomerization would be
preferred to synthesize the CLA because it pro-
duced equal amounts of these two isomers.
5
Ip, C., Chin, S.F., Scimeca, J.A., Pariza, M.W., 1991. Mam-
0, 1097Á1101.
/
mary cancer prevention by conjugated dienoic derivative of
linoleic acid. Cancer Res. 51, 6118Á6124.
/
Jiang, J., Bjorck, L., Fonden, R., 1998. Production of con-
jugated linoleic acid by dairy starter cultures. J. Appl.
Microbiol. 85, 95Á
Kepler, C.R., Tove, S.B., 1967. Biohydrogenation of unsatu-
rated fatty acids. J. Biol. Chem. 242, 5606Á5612.
/
102.
/
Knekt, P., Jarvinen, R., Seppanen, R., Pukkala, E., Aromaa,
References
A., 1996. Intake of dairy products and the risk of breast
cancer. Br. J. Cancer 73, 687Á691.
Lee, K.N., Kritchevsky, D., Pariza, M.W., 1994. Conjugated
/
Berdeaux, O., Christie, W.W., Gunstone, F.D., Sebedio, J.L.,
1
997. Large-scale synthesis of methyl cis-9, trans-11-octa-
decadienoate from methyl ricinoleate. J. Am. Oil Chem.
Soc. 74, 1011Á1015.
linoleic acid and atheroclerosis in rabbits. Atheroclerosis
1
08, 19Á25.
/
/
Leung, Y.H., Liu, R.H., 2000. Trans-10, cis-12-conjugated
linoleic acid isomer exhibits stronger oxyradical scavenging
capacity than cis-9, trans-11 conjugated linoleic acid
Body, D.R., Shorland, F.B., 1965. The geometric isomers of
conjugated octadecadienonates from dehydration of methyl
ricinoleate. J. Am. Oil Chem. Soc. 42, 5Á8.
/
Chen, Z.Y., Chan, P.T., Kwan, K.Y., Zhang, A., 1997.
Reassessment of the antioxidant activity of conjugated
isomer. J. Agric. Food Chem. 48, 5469Á5475.
/
Li, Y., Watkins, B.A., 1998. Conjugated linoleic acids alter
bone fatty acid composition and reduce ex vivo bone
prostaglandin E2 biosynthesis in rats fed n-6 or n-3 fatty
linoleic acids. J. Am. Oil Chem. Soc. 74, 749Á
Chin, S.F., Liu, W., Storkson, J.M., Ha, Y.L., Pariza, M.W.,
992. Dietary sources of conjugated dienoic isomers of
linoleic acid, a newly recognized class of anticarcinogens. J.
Food Comp. Anal. 5, 185Á197.
/753.
1
acids. Lipids 33, 417Á425.
/
Lin, Y., Kreeft, A., Schuurbiers, J.A., Draijer, R., 2001.
Different effects of conjugated linoleic acid isomers on
lipoprotein lipase activity in 3T3 adipocytes. J. Nutr.
/
Cook, M.E., Miller, C.C., Park, Y., Pariza, M.W., 1993.
Immune modulation by altered nutrient metabolism: nutri-
tional control of immune-induced growth depression. Poul-
Biochem. 12, 183Á189.
/
Lie Ken Jie, M.S.F., Pasha, M.K.&, Alam, M.S., 1997.
Synthesis and nuclear magnetic resonance properties of all
geometrical isomers of conjugated linoleic acids. Lipids 32,
try Sci. 72, 1301Á1305.
/
Dugan, M.E.R., Aalhus, J.L., 1999. Feeding CLA to pigs. In:
Yurawecz, M.P., Mossoba, M.M., Kramer, J.K.G., Pariza,
M.W., Nelson, G.J. (Eds.), Advances in Conjugated Lino-
1
041Á1044.
/