Functional properties in vitro and physiological effects in vivo of new sources of dietary fiber in Holtzman rats

The endosperm of tara seeds (EST) and powder from the leaves of Agave americana (HAA) were evaluated as new sources of dietary fiber, using wheat bran (ST) as a reference. In vitro experiments were carried out to determine functional properties and in vivo experiments were used to determine the physiological effects of fed Holtzman rats with diets with 6% of each fiber source. Endosperm of tara had 32.2% solubility, 45.0 and 47.9 g/g absorption and water retention capacity, respectively, and 46 ml/g swelling, values significantly higher than wheat bran (p<0.01). On the other hand, Agave had higher adsorption capacity of oil than wheat bran (6.38 g/g vs. 5.27 g/g; p<0.01). Diets with endosperm of tara, were 8.76% of fecal fat, a value that exceeded that of wheat bran (p<0.01); however, there was no effect on body weight of the rats. Agave increased fecal volume and reduced (p<0.01) intestinal transit time from 14.9 to 10.4 h. Endosperm of tara retained and eliminated fat from the diet through the feces; on the other hand, the powder of Agave leaves reduced intestinal transit time.