Estimation of cold denaturation temperature and its utilization in predicting protein stability as an aid in functionalizing pea protein isolate through cold denaturation

Abstract

Plant-based proteins are commonly used to generate new textures in food by inducing changes in their molecular structures with the application of heat, shear, pressure, and other methods of protein denaturation. One structural transformation that is relatively less understood is cold denaturation, which mainly occurs due to a weakening of hydrophobic forces at low temperatures. In this work, the Gibbs-Helmholtz equation is used to produce stability curves and estimate the temperature of cold denaturation for pea protein. The equation is solved with data obtained from differential scanning calorimetry conducted as a function of the solution pH and salt concentration. It is found that at pH 3, the temperature of cold denaturation is 3.85 °C. The protein functionality is then tested through zeta potential, surface hydrophobicity, solubility, and the emulsion activity/stability index at these low temperatures and compared to results from room temperature. It is found that surface hydrophobicity increases, the magnitude of the zeta potential increases, solubility decreases, and the emulsion activity/stability increases at low temperatures.