Iodine → Linolenic Acid

Participants

Reaction Steps

54 mg. of soybean oil (containing by weight fatty acid moieties on a fatty methyl ester basis as follows: palmitic, 9.7%; stearic, 4.6%; oleic, 23.2%; linoleic, 53.9%; linolenic, 7.7%; other, 0.9%) was added to 5 milliliters of hexane (δ=7.3, δD =7.3, δP =0, and δH =0) and 1.0 gram Amberlyst 15 ion exchange resin with 100% of its cationic substituents being silver substituents, in a screw-cap vial. This was placed on a wrist action shaker at 27° C. overnight. A 1.0 milliliter aliquot of the supernatant liquid was removed, freed of hexane with a nitrogen stream, weighed, multiplied by 5 to give 35.5 mg. in the bulk liquid and by difference 18.5 mg. adsorbed. The bulk liquid material was converted to methyl esters with sodium methoxide/methanol, the resulting ester mixture analyzed by gas chromatography and selectivities were calculated according to the aforementioned formula using methyl esters as the components M and N. These selectivities were as follows: methyl stearate/methyl palmitate, 0.4; methyl oleate/methyl palmitate, 1.5; methyl linoleate/methyl palmitate, 5.2; and methyl linolenate/methyl palmitate, 42.4. These selectivities demonstrate that triglycerides of higher Iodine Value were preferably adsorbed and that a soybean oil fraction was produced with dramatically reduced linolenic acid moiety content.

Provenance & Evidence