EFFECTS OF A FIBER CONCENTRATE FROM CITRUS-FRUITS IN HUMANS

Ten female subjects consumed a fiber concentrate made from citrus fruits under strict dietary control in a randomized cross over study comprising 2 experimental periods each of 4 wk duration. The citrus fiber concentrate contained 68.6 g total dietary fiber per 100 g, half of which was soluble. The fiber preparation was incorporated into various fiber free or low fiber foods in an amount providing 24 g total dietary fiber daily. The control diet contained these foods but without added fiber. Total dietary fiber intake was 21.2 and 45.1 g/d during the control and the high fiber diet periods, respectively. When the control diet was fed, mean total serum cholesterol levels remained stable, whereas high density lipoprotein (HDL)-cholesterol was reduced by 6.5 % after 4 wk. When the citrus fiber was consumed for 4 wk, both serum total and HDL-cholesterol levels were decreased significantly by 10.6 and 14.5%, respectively. The addition of citrus fiber to the diet increased fecal wet and dry weight by 1.5 and 0.2 g, respectively, per gram of additional fiber. Fecal excretions of both energy and nitrogen were increased due to the intake of citrus fiber, whereas fecal fat was not affected. The additional fiber source was fermented completely. The partial digestible energy value of the citrus fiber was calculated to be 12 kJ (2.9 kcal)/g.