Effect of metal ions on the soybean protein by freezing

Different metal ions were adding into soybean protein solutions and freezing treatment had been used to produce soybean protein in order to determine the production of soybean protein affected by the metal ions.It was suggested that protein content increased significantly at the solid-liquid ratio 1:20, the heated temperature 50℃, pH5, after adding of metal ions, then freezing at-18℃ for 24h.The precipitation of protein content of calcium chloride and magnesium chloride were much more than that of chlorine sodium, which was in accordance with the Hoffmann Manchester-ion sequence.The solubility of the protein increased with the concentration of the metal ions, while water holding capacity showed various trends.It was clearly showed that soybean protein was strongly promoted by calcium and magnesium ions through freezing treatment, while much less of sodium ions.