Conjugated linoleic acid isomers in partially hydrogenated soybean oil obtained during nonselective and selective hydrogenation processes

Partially hydrogenated soybean oil samples were collected during selective and nonselective hydrogenation processes. The formation of conjugated linol eic acids (CLAs) during hydrogenation was greatly dependent on the types an d duration of hydrogenation processes. During hydrogenation processes, CLA contents increased initially. After reaching maximum CLA content;, the cont ent decreased during hydrogenation. Selective hydrogenation was much more f avorable for the formation of conjugated linoleic acids. With nonselective hydrogenation process, the total CLA content was a maximum (9.06 mg total C LA/g oil) at 35 min. However, with the selective hydrogenation process, the total CLA content was a maximum (98.27 mg total CLA/g oil) at 210 min. The CLA, contents in some of the tested selectively hydrogenated soybean oils were among the highest ever reported in foods.