Driving forces of disaggregation and reaggregation of peanut protein isolates in aqueous dispersion induced by high-pressure microfluidization

Abstract

Our previous report described that high-pressure microfluidization (HPM) treatment can disaggregate peanut protein isolates (PPIs) to prepare antihypertensive peptide fractions. In the present study, we investigated the driving forces of disaggregation and reaggregation of PPIs in aqueous dispersion induced by HPM treatment and discussed the mechanism. The driving forces of hydrogen bonds, surface hydrophobicity, sulfhydryl/disulfide bonds (SH/SS) and ζ-potential, which are responsible for disaggregation and reaggregation, were studied. HPM treatment changed the polar environment and promoted surface hydrophobicity and the formation of disulfide bonds (SS), while the free sulfhydryl (SH) group content was decreased. The magnitude of the ζ-potential and β-sheet content increased when the pressure was ≤120 MPa. However, the magnitude of those values decreased when the pressure was >120 MPa. Hydrophobic interactions, SH/SS interchange reactions, hydrogen bonds and electrostatic interactions cannot individually induce changes in PPIs. Combination of the applied forces drove the disaggregation and reaggregation of PPIs in aqueous dispersion.

Keywords: Driving forces; High-pressure microfluidization; Peanut protein isolate.