Thermal Aggregation of Soybean (Glycine max L.) Sulfur‐rich Protein

Abstract
The sulfur‐rich protein (SRP) in soybeans aggregated at ≥ 70°C due to thermal denaturation of the protein and subsequent formation of soluble and insoluble aggregates. Aggregation was dependent on heating temperature, time, buffer composition, and the presence or absence of protein modifying agents in the heating buffer. Hydrophobic interactions and disulfide bonds helped stabilize the protein against thermal aggregation while hydrogen bonds and sulfhydryl exchange promoted it. At pH 7.6, 4.5 mg protein/mL, 70°C and 1.0M salt concentration, the rate of thermal aggregation was dependent on the anion type and followed lyotropic series SCN‐> I‐> Br‐> Cl