不飽和脂肪酸の異性化に関する研究 (第4報)
リノール酸メチルの熱変化に伴う酸素の影響
1961 年 10 巻 1 号 p. 29-32
詳細
1961 年 10 巻 1 号 p. 29-32
It was known that unsaturated fatty acids were very sensitive to oxygen, but little studies on the thermal isomerization were made. We investigated the effect of thermal change of methyl-linoleate.
The isomerization was conducted by passing nitrogen containing 1, 5 and 10 vol% of oxygen into pure cis methyl-linoleate at the rate of 3l/hr at 100 and 200°C. The obtained results are summarized as follows :
1) In the presence of oxygen, cis methyl-linoleate isomerizes rapidly, even at low temperature, to trans-trans conjugated or trans non-conjugated one.
2) The increase of oxygen content is only effective to increase the speed of isomerization.
3) At the first stage of isomerization, the yield of trans-trans conjugated isomer is almost independent of the oxygen content. This can be explained by the assumption that oxygen is consumed by the polymerization or oxidation reactions (such as to -OH, -OOH or = CO).
4) The formation of trans-trans conjugated isomer reaches to the equilibrium concentration of about 12%. This may due to either the polymerization of the resulting conjugated isomer, or its isomerization to the thermal stable trans non-conjugated isomer.
5) Although Lundberg reported the formation of cis-trans conjugated isomer in the oxidation of methyl-linoleate, only trans-trans isomer was found in our experiment.
