The interaction between soybean protein and water can be divided into two types: water absorption and water retention. Water absorption refers to a chemical combination between soybean protein and water, and water retention refers to the physical retention between soybean protein and water. . The process of water absorption is an exothermic reaction, and the order of water molecules after binding on the protein surface increases, similar to the condensation of water vapor. The dry protein interacts directly with liquid water, and the absorbed water is called water holding capacity. It is a macroscopic phenomenon. Water holding capacity is mainly determined by the pH value rather than the concentration.
