Digestibility and Dietary Quality of Nonacetylated and Acetylated <i>Vicia faba </i>Proteins in Maintenance

Abstract

N digestibility and the dietary quality of a Vicia faba protein isolate as well as of two protein fractions from this isolate, acetylated and nonacetylated, were estimated in ¹⁵N-labelled adult rats. For reference, whole egg, casein and wheat were studied. The diets were fed at maintenance energy intake level. Daily metabolic fecal nitrogen estimated by an isotopic method was 5 mg/l00 g body weight in animals receiving whole egg, casein, or Vicia faba proteins. When wheat was included in the diet metabolic fecal nitrogen was increased to 140% of this value. True N digestibility of reference proteins was 91-92% and of Vicia faba proteins 95-97%. Protein quality for maintenance was high and similar for all proteins. Acetylation affected neither N digestibility nor protein quality under maintenance conditions.

Effect of Spinning and Additional Cross-Linking with Dialdehyde Starch or Aluminum Ions on the Digestibility and Quality of Casein-<i>Vicia faba</i>Protein Isolate Mixtures

“…As in the previous study, and with the exception o f wheat, the amount of MFN was found to be in the normal range; approximately 5 m g/100 g body weight (ta ble II). In the diets with wheat MFN was nearly doubled and is associated with the increased crude fiber content [ 1,11]. …”

“…As in ear lier studies in which nonacetylated and acetylated fractions of V. faba protein isolate were tested [ 1] an isotopic method was ap plied [2, 11).…”

“…The general composition of the diets for the pre liminary, labelling and experimental periods was sim ilar to that in the previous experiment [ 1 ]. The protein content of the diets was adjusted to 10% on a dry matter basis.…”

Pattern of Fecal Endogenous Nitrogen Excretion in Rats Fed Leguminous Diets.

“…The influence of beans, bean proteins or bean diets on the dry weight of feces, fecal nitrogen, secretion and excretion of endogenous nitrogen has been the subject of research by many investigators (6,8,9,15,19,20). The power equations determined by regression analysis do in fact show the pattern of excretion of the rat corporal nitrogen.…”

The Use of Nitrogen-15 Labeling for the Assessment of Leguminous Protein Digestibility.

“…The influence of these seeds on rat fecal endogenous nitrogen excretion as on digestive secretions and epithelial desquamation, was investigated (2)(3)(4) and, in all cases, authors found increased secretion and excretion by animals fed cooked legumes, which could indirectly contribute to decreased protein digestibility values. By using 15 N isotopic labeling of bean protein, it was possible to identify the contribution of endogenous nitrogen to total fecal nitrogen excreted by animals fed these labeled seeds and to determine the digestibility values, which were called real (5).…”