Allergenicity, trypsin inhibitor activity and nutritive quality of enzymatically modified soy proteins

• Published in: International journal of food sciences and nutrition 2005-05, Vol.56 (3), p.203-211
• Main Authors: Barca, Ana María Calderón De La, Wall, Abraham, López-Díaz, José Alberto
• Format: Article
• Language: English
• Subjects: Allergenicity; Allergens - immunology; Allergies; Amino acids; Amino Acids - analysis; Animals; Biological and medical sciences; Cattle; enzymatically-modified; Feeding. Feeding behavior; Food Hypersensitivity - immunology; Food Hypersensitivity - metabolism; Food science; Food, Fortified; Fundamental and applied biological sciences. Psychology; Humans; Hydrolysis; Infant; Methionine; Milk Proteins - immunology; Milk Proteins - metabolism; Nutritive Value; nutritive-quality; Proteins; Rats; Rats, Sprague-Dawley; Soy products; soy-protein; Soybean Proteins - immunology; Soybean Proteins - metabolism; Trypsin Inhibitors - metabolism; Vegetable Proteins - analysis; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0963-7486; 1465-3478
• DOI: 10.1080/09637480500146762

Two ultrafiltered soy flour protein fractions were evaluated; the first was obtained by hydrolysis (0.5-3 kDa, F0.5-3), and the second was an enzymatically methionine-enriched fraction (1-10 kDa, F1-10E). Amino acid profiles, protein quality, allergenicity (against soy-sensitive infant sera) and trypsin inhibitor activity were determined. Fraction F1-10E fulfilled amino acid requirements for infants, whereas the F0.5-3 fraction was methionine deficient. Both fractions were similar in net protein utilization, and F1-10E digestibility was comparable with casein and higher (P < 0.05) than F0.5-3 or soy isolate. Allergenicity of SF was reduced to 21.5% with the hydrolysis in F1-10E and it was not detected in F0.5-3. Residual trypsin inhibitor activity with respect to soy flour was 8.1%, 3.3% and 1% for hydrolysate, F1-10E and F0.5-3, respectively. Both fractions presented high nutritive quality and reduced or null allergenicity. The trypsin inhibitor activity decreased along processing and could be a useful indicator for production of hypoallergenic proteins.