Enzymatic modification of the functional, nutritional and sensorial properties of soy protein for special nutrition.

Production of new protein-based products for optical nutrition such as hypo allergenic infant formulas, fortified beverages and nutraceutics, require i deal ingredients. Protein ingredients were developed by enzymatic hydrolysi s and methionine synthesis of soy protein. Hydrolysis was done at 4% (w/v) using porcine pancreatic enzymes (4% w/w), 50 degrees C, 6 h and pH 8. Afte r drying powder was resuspended (20% w/v) and incubated with 7.6% (w/w) met hionine methyl-ester, 1% (w/w) chymotrypsin and 3 M glycerol. 37 degrees C. 3h and pH 7. Hydrolysates were fractionated cl by ultrafiltration (UF) bef ore and after enrichment (E): Fl>10, 10>FII>3 and 3>FIII>1 kDa. Functional properties, amino acid content, anti-physiological factor activities and an tigenicity were assayed for all the UF fractions and the soybean meal. Prot ein quality bioassay and sensorial test of an non-enriched fraction and an enriched fraction were performed. Functional properties were positively mod ified by hydrolysis and synthesis by using a minimum time and methionine ad ded for the last reaction. After UF all the fractions under 10 kDa showed 1 00% solubility (pH 4 and 7), good clarity, acceptable foam capacity and neg ligible antigenicity and anti physiological activities. Additionally, methi onine enrichment enhanced their nutritional value, upgrading sulfur amino a cid requirements for infants and adult. Because functionality and nutrition al value FIII-E could he used for hypoallergenic infant formulas, FII-E for fortified soluble formulas and nutraceutics and FI-E for a semi-solid baby food.