Cereal Chem 58:375 - 380.  |  VIEW ARTICLE
Effects of Rat Digestion upon Native, Enzymically or Chemically Modified Wheat Brans and Native Oat Bran.

D. Bertrand, J. M. Brillouet, V. F. Rasper, B. Bouchet, and C. Mercier. Copyright 1981 by the American Association of Cereal Chemists, Inc. 

Utilization of native or modified cereal brans by the rat was investigated. In a first experiment, during a four-week period, weanling rats were fed one of six diets: control, oat bran, or native, air-classified, enzymically destarched, or chemically delignified wheat bran. Excretion variables (rate, transit time, feces moisture, stool weight, and defecation frequency) were measured. Dietary fiber of the collected feces was analyzed. In a second experiment, adult rats were fed for four days with a control diet or with isofibrous diets containing enzymically destarched or chemically delignified wheat bran or hemicellulose A extracted from the same wheat bran. Excretion variables and apparent digestibility of the dietary fiber components were measured. Wet feces excretion rate, feces moisture, stool weight, and defecation fequency were positively correlated with the dietary fiber content of the diet, whereas transit time was negatively correlated. Cellulose apparent digestibility was around 15% and lignin digestibility about 0%, whereas digestibility of hemicellulose was as high as 50% except for that of hemicellulose A (95%). Differences in degradation of cell-wall polysaccharides were studied; water-soluble hexosans of oat bran and of native and air-classified wheat brans were easily digested, whereas for all bran samples studied, hexosan and pentosan moieties of insoluble hemicelluloses were degraded to the same extent. Of the monomeric sugars, beta- glucans were the most degradable, followed by xylan and then arabinan. An overall correlation matrix was established for nutritional, biochemical, and physical data.