**5.3 Solubilization and recovery of protein**

To adjust protein solubility, the pH and ionic strength of the solubilization media are frequently changed to extract proteins from either constituent of defatted wheat. Because most food materials, including legumes and insects, have an isoelectric point (pI) of between 4 and 5, excessive pH values cause the protein surface to become charged, enhancing both electrostatic repulsion between proteins and proteinwater associations [63–65]. To increase protein solubility, ionic strength can also be changed. Salt ions operate as a "shield" for proteins with opposing surface charges at low ionic strength (0.5–1 M), enhancing protein-water association and water solubility [66]. This method is known as salting in. The protein solution is normally centrifuged or gently eluted to complete the solubilization process. Proteins and other water-soluble constituents are retrieved from the supernatant, whereas water-insoluble polysaccharides and other minor components are eliminated from the pellet [54].
