[Physico-chemical properties related to gastrointestinal function of 6 sources of dietary fiber].

The physicochemical properties of the six sources of dietary fiber more commonly consumed in Mexico were studied. The knowledge of these properties may allow a prediction of the functional effect of the fibers on the GI tract. The content of dietary fiber varied from 43% in wheat bran (WB) to 87% in Psyllium plantago (PP). Glucomannan (GM) showed the highest proportion of soluble fiber (97%) followed by dried cactus from Opuntia sp (DC) (28%) and PP (13%), whereas WB and soy isolate (SI) showed the highest proportion of insoluble fiber (95 and 92%, respectively). PP and GM showed a higher water holding capacity and viscosity and a lower ion exchange capacity: we anticipate that these fibers would be more effective to regulate plasma levels of glucose and cholesterol in contrast, WB and SI with a lower water holding capacity and viscosity and a higher proportion of insoluble fiber would be more effective to increase fecal bulk. Fibers from DC and from cactus fiber isolate were intermediate in these responses.