Digestibility of collagenous fermented sausage in man

The digestibility of the protein of a fermented collagenous sausage was studied in three patients with ileostomies with small bowel resections. The patients were given four ordinary meals each day with a total protein content of about 64g, half of which was derived from collagen. Pigskins from 6-month old scalded pigs were used as the collagen source. A fermented sausage, based on meat, was used as a reference and the patients with ileostomies served as their own controls. Urine was collected from two patients. The true nitrogen digestibilities were found to be 71-79 % for the collagenous diets and 69-85 % for the reference diets. Hydroxyproline digestibilities (apparent and true) for the collagenous diet periods were similar: 70-82 %. This indicated that collagen was digested to the same extent as other proteins. Amino acid patterns of ileal excreta distinctly differed for each of the two periods, further confirming that all the protein was not absorbed. Elevated excretion of hydroxyproline in the urine after ingestion of the collagenous sausage was found, mainly as peptide bound hydroxyproline, but accounted for about only 2% of the ingested hydroxyproline. It was concluded that collagenous fermented sausage is as digestible as a reference sausage based on meat even without prior heat treatment.