Abstract
Food protein is denatured by various actions from the outside, such as cooking or freezing, and it gives some effects to the texture of food.
Experiments were carried out to examine the phenomena occured by the denaturation of protein.
1. When 3% solution of milk casein which contains sugar (0%, 20%, 40%, or 60%) was precipitated at isoelectric point (pH 4.6) at room temperature, the size of precipitates became smaller as the percentage of sugar rose. For the solutions of lower sugar contents, the size of precipitates was varied in a solution.
2. When one of the substances listed below was added into 3% solution of milk casein, instead of sugar, the same results as above were obtained : sodium chloride, agar-agar, egg-white, gelatinized potato starch, and soluble starch.
3. When substances such as milk, soybean milk, dried egg white solution and soybean casein contained sugar and were denatured by acid, heat or salt, the size of precipitates was varied according to the percentage of sugar as we had seen in former experiments.
