Effect of Polysaccharide Conjugation or Transglutaminase Treatment on the Allergenicity and Functional Properties of Soy Protein

Abstract

The soy protein−galactomannan conjugate prepared by the Maillard reaction removed the allergenicity of the 34 kDa protein which is frequently recognized by the IgE antibody in the sera of soybean-sensitive patients as a major allergen. Monitoring of polyclonal antibody titers by an indirect enzyme-linked immunosorbent assay and immunoblotting of rabbit sera, monoclonal antibody, and human allergic sera showed that soy protein−galactomannan conjugation was more effective in reducing the allergenicity of the soy protein than transglutaminase treatments and/or chymotrypsin. The soy protein−galactomannan conjugate was highly soluble at all pHs, while untreated soy protein was sparingly soluble at pH 4−6. Heat stability and emulsifying properties were greatly improved by conjugation with galactomannan. Keywords: Galactomannan; transglutaminase; allergenicity; soy protein−polysaccharide conjugate; functionality