The Effect of Environmental Conditions on the Physical Properties of Protein (Part 2)

The Effect of Temperatures on the Protein Precipitation at the Isoelectric Point

Abstract

To systematically study the phenomena that were caused by the denaturalization of protein, some experiments were made, continued from the previous report.
The 3% solution of milk casein was warmed at 20, 30, 40, 50, 60, 70 and 80°C respectively, and precipitated at the isoelectric point, being stirred constantly with Magmixstirrer. There were various shapes of the precipitate and at 40, 50, and 60°C, the precipitates agglomerated into a ball.
When milk and soybean casein were precipitated by acid, precipitates showed various figures at different temperatures (at 20, 30, 40, 50 and 60°C for milk and at 25, 40 and 60°C for soybean casein) similarly to milk casein. The particle sizes of the precipitates became larger as the temperature rose.