Characterization of soybean protein isolates. The effect of calcium presence

SCILINGO, A.A., AÑON M.C.

JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY (JAOCS)

Año: 2004 vol. 81 p. 63 - 69

0003-021X

Results of a study of the effect of calcium addition on polypeptide composition, hydrophobicity, sulfhydryl content,thermal stability, enthalpy of denaturation, and water solubility of soybean protein isolates suggest that the addition of small amounts of calcium (1.23¨C5.0 mg/g protein) induced the formation of ¦Á,¦Á¡ä soluble aggregates, whereas large amounts (5.0¨C9.73 mg/g protein) induced the selective nsolubilization of the glycinin fraction. The addition of this ion also produced thermal stabilization of the soybean proteins, mainly the glycinin fraction, and increased the enthalpy of denaturation. A decrease in the surface hydrophobicity of proteins with increasing calcium content was also observed. The results obtained suggested the existence of specific calcium¨Csoy protein interactions, especially with the glycinin fraction.