1986 Volume 33 Issue 11 Pages 764-768
Soybean fibrous protein of 0.8mm diameter was prepared by acid coagulation from dope solution. Procedure to fix the fibrous protein at its isoelectric point were examined by immersing it in salt solutions. With sodium acetate or dibasic sodium phosphate solutions of pH 4.0-6.0, it took about five minutes to increase pH of the fibrous protein to its isoelectric point under room temperature, whereas it took longer time with sodium chloride solution under the same conditions. When the fibrous protein was fixed upon heating in sodium chloride solution, solubility of protein in the solution increased with increasing heating temperature and time under conditions at 50-80°C for 2.5-10.0min. Although the solubility was low with statistical significance when the fibrous protein was fixed in sodium chloride solution at pH 4.5 or 2.5% sodium chloride solution at 50°C, it was independent of concentration of sodium chloride at pH 6.5 or 65°C. Practical procedure to fix the fibrous protein seemed to be heating at 70°C for 10min in 5% sodium chloride solution at pH 6.5.
