Relationship between dietary fiber levels and protein digestibility in selected foods as determined in rats

Abstract

Samples of 15 food products and feces obtained by feeding them to rats were analysed for dietary fiber fractions. The food products were added as the sole source of protein in 8% protein diets, making up 8.8-51.6% of the diets. Diets were supplemented with 0.54-5.00% purified cellulose to make them more comparable in total fiber. Fiber analyses of food products revealed that the protein sources provided 0.06-7.27% total dietary fiber. The true protein digestibility in rats was negatively correlated with the total food fiber level (r = -0.69, P less than 0.01) or with the food cellulose level (r = -0.82, P less than 0.01) but it was positively correlated (r = +0.81, P less than 0.01) with the purified cellulose level. No relationship was found between protein digestibility and fiber fermentability. Results indicate that several food fiber fractions and possibly associated substances influenced protein digestibility. Purified cellulose did not have the same physiological behavior as food cellulose from the viewpoint of protein digestibility and fiber fermentability.

The impact of germination and dehulling on nutrients, antinutrients, in vitro iron and calcium bioavailability and in vitro starch and protein digestibility of some legume seeds

“…Dehulled samples had the highest levels of in vitro starch and protein digestibility that may be attributed to lowered levels of antinutrients. Findings about interaction of starch with fiber, phytic acid and tannin (Flores, Castanon, & McNab, 1994;Reddy, Sathe, & Salunkhe, 1982;Thorne, Thompson, & Jenkins, 1983), suppression of pepsin activity by dietary fiber and consequent reduction of in vitro protein digestibility (Horie, Sugase, & Horie, 1995;Mongeau, Sarwar, Peace, & Brassard, 1989), negative correlation between phytic acid and tannin with in vitro digestibility of protein support this study observations (Agarwal & Chitnis, 1995;Kumar & Chauhan, 1993). Significant negative correlations (Po0.05) were observed between in vitro starch and protein digestibility and phytic acid, tannin and total dietary fiber, with least correlation in case of fiber (Tables 5 and 6).…”

Comparative study of natural carob fibre and psyllium husk in rats. Influence on some aspects of nutritional utilisation and lipidaemia

“…These results are in accordance with other authors who indicated that diþerent übres modify the net protein utilisation more than cellulose. 28,33 For the lipid component of these diets (Table 3), no signiücant diþerences were observed for fat absorption between the groups that consumed PSY (0.94^0.01) and CEL (0.95^0.01) but this parameter was signiücantly reduced in the animals consuming NCF (0.91^0.01) compared to the control group. This outcome seems to indicate that NCF is more speciüc than PSY at binding lipids in the digestive tract.…”

Nutritional composition of uncommon foods and their role in meeting micronutrient needs

“…High fibre content as well as fraction associated with the fibre such as phytates and protease inhibitors causes low protein digestibility (Ikeda et al, 1986;Mongeau et al, 1989). Crude fibre content in samples was low and ranged between 0.88 to 5.02 g/100 g. Fat content in samples was low and ranged between 0.23 to 1.38 g.…”