State diagrams of soy globulins

State transitions of 7S and 11S soy globulins were studied as a function of moisture by monitoring their rheological and calorimetric properties. Small-amplitude oscillatory rheometry and differential scanning calorimetry (DSC) were used to characterize their denaturation and complexing reactions within a temperature range of 40–200 °C and moisture contents of approximately 20%, 30%, and 40%. Major increases in rheological properties showed that the 7S and 11S fractions with 40% moisture underwent structure forming reactions above 70 and 100 °C, respectively, while they reacted at higher temperatures for lower moisture. DSC helped to identify the individual complexing behavior of each fraction. The above, along with the information from their glass transition, previously reported, allowed us to develop state diagrams for each protein, where glassy, rubbery, entangled polymer, reaction, and free-flow states were identified.