Production and Characterization of Enzymatic Hydrolysate from Soy Protein Isolate

Soy protein isolate was enzymatically hydrolysed, for its potential use in clinical nutrition, using pancreatin as the hydrolytic agent. The hydrolysate, after separation of the insoluble fraction, showed differences in its amino acid composition with respect to soy protein isolate. There was a decrease in the content of the essential amino acids, Val, Leu and Phe, and an increase in Lys and Trp. The average peptide size was evaluated using gel exclusion chromatography on Sephadex G-25, total and free amino acid analysis, and NH2-group determination. The peptide size distribution of the hydrolysate was 0.24 peptides with 18 residues, 0.27 with 12 residues, 0.38 peptides with 2–5 residues and 0.12 free amino acid. This size distribution was similar to that of casein and soy protein hydrolysates which have been used successfully in clinical nutrition.