Effect of addition of high fiber ingredients on protein quality of casein and gluten diets assessed by bioassays in growing rats (540.8)

Abstract

The food industry has responded to consumer demand for foods with higher fiber content, developing products with high‐fiber ingredients. These ingredients have unique properties that raise the level of fiber. Excessive consumption of high‐fiber products can have an impact on the digestibility and protein quality. The aim of this study was to evaluate the effect of three commercial products used to increase fiber content of food on the protein quality of diets based on casein and gluten bioassays, employing Sprague Dawley rat as an experimental model. Six synthetic diets were prepared, three of casein, and three of gluten with three different ingredients high in fiber: insoluble fiber from wheat bran, soluble fiber with resistant maltodextrins and fiber obtained from orange pulp formed by similar amounts of fiber soluble and insoluble. Biological indicators were determined, Net Protein Ratio (NPR) and % Apparent and true digestibility of nitrogen (ADN, VDN). Results were analyzed by a statistical program with 95% significance. ADN and VDN of casein diets with high fiber ingredients ranged from 83.7 to 86.2% and from 86.6 to 89.1% respectively. In gluten diets with different fiber ADN and VDN ranged from 88.0 to 90.5% and from 91.1 to 94.8% respectively and NPR results ranged from 1.44 to 1.77. The results showed that commercial fibers showed significant differences in digestibility and RNP gluten diets.