VARIOUS DIETARY FIBERS DECREASE THE RATE OF LIPASE-CATALYZED HYDROLYSIS OF OLIVE OIL IN VITRO

An in vitro method was used to evaluate the effect of different types of dietary fiber on the initial rate of hydrolysis of olive oil catalyzed by porcine pancreatic lipase. Lipolysis was measured at pH 6.5 and 37C while stirring at 20 rpm. Excellent recoveries of added known amounts of oleic acid were obtained in control and fiber-containing samples. Dietary fibers tested (all 3% by weight unless otherwise noted) were: red wheat bran, white wheat bran, oat bran, soyfiber, sugarbeet fiber, chitin, chitosan, cellulose, pectin-LM and psyllium seed (1.5%). All inhibited lipolysis (35–85%) except cellulose and pectin. The contribution of aqueous extracts of the insoluble fibers to the total inhibitory properties of the fibers were: 0% for the two wheat brans; 100% for oat bran, chitin, chitosan and sugarbeet fiber; and 63% for soyfiber.