Balanced intraintestinal nutrition: digestion, absorption and biological value of selected preparations of milk proteins.

The absorption of an enzymatic hydrolysate of whey proteins, hydrolysates of milk proteins and casein, 7% hydrolysate of bovine blood produced by Polfa under the trade name "Aminokwasy", and a standard mixture of amino acids from isolated small intestine loop of dogs and rats was compared. The composition of amino acids of the initial proteins and hydrolysates obtained from these proteins was determined. The biological value of selected proteins and hydrolysates was assessed determining the mean weight gain, nitrogen content of the body, urinary excretion of urea and creatinine, blood urea level and NPU. No significant differences were found in the absorption of nitrogen from the hydrolysate of milk and whey proteins. The nutritional value of whey protein hydrolysate was, however, slightly higher than that of an analogous hydrolysate of milk proteins. It seems that of all tested proteins whey hydrolysate (free of lactose) is the most suitable source for obtaining preparations for no-residue intraintestinal feeding.