Abstract
A dried black soybean was soaked in water or in NaCl solution with different concentration of 0.8%and 2.0%. Water was added to the 2.0% NaCl solution before heating so as to make the concentrations of both NaCl solutions same. Then they were boiled.
Boiled beans were different in color and hardness there upon a mechanism causing the difference of hardness was investigated by the fractional determination of pectin.
Water-soluble pectin was much in the boiled beans prepared after soaking in the 2.0% solution. It was shown to be more adhesive in texture. The boiled beans soaked in 2.0% NaCl solution were extremely black.
