DIETARY NON-EXTRACTABLE CONDENSED TANNINS AS INDIGESTIBLE COMPOUNDS -EFFECTS ON FECAL WEIGHT, AND PROTEIN AND FAT EXCRETION

The possible degradation of non-extractable condensed tannins (NECT) w ithin the intestinal tract and their effect on faecal weight and compo sition was studied. Two groups of male Wistar rats were fed either a N ECT-free control diet, or a diet containing 100 g carob pod concentrat e kg-1 (53 g NECT kg-1 dry matter) for 5 weeks. A slight effect of NEC T on growth rate was observed in the fifth week. The NECT diet did not affect food intake. Significant increases of total faecal output as w ell as water, nitrogen and fat excretion were observed. NECT were not degraded in the intestinal tract, since they were quantitatively recov ered in faeces (98 +/- 1 %). Since the usual spectrophotometric method s gave contradictory results on NECT levels in the diet and faeces, an alternative method based on Klason lignin residues was used.