Various dietary fibers have different effects on lipase-catalyzed hydrolysis of tributyrin in vitro.

The ability of various dietary fibers to impede lipase-catalyzed hydrolysis of tributyrin was studied in vitro. Conditions (temperature, kind and concentration of constituents, pH, agitation) were chosen to mimic, as closely as possible, those prevailing in the human duodenum. Lipolysis was monitored at pH 6.0 and 37 degrees C using a constant pH titrimeter. Some fibers inhibited lipolysis (red wheat bran, white wheat bran, oat bran and sugarbeet fiber), whereas most did not (psyllium seed, pectin LM 12CG, carrageenan, carboxymethylcellulose, gum arabic, and pectin slow set). Water extracts of the fibers accounted for 32-41% of the inhibitory effect of the two wheat brans on lipolysis and 100% of the inhibitory effect of oat bran.