Supercritical carbon dioxide treatment of plum (Prunus domestica L) kernel protein isolate: Impact on structural, thermal, physical, and functional properties

Abstract

The effects of supercritical carbon dioxide (SC–CO2) treatment at varying processing temperatures (30–70 °C) on the physicochemical, structural, thermal, and functional properties of plum kernel protein isolate (PKPI) were investigated. The results revealed that SC-CO2 treatment at 60 °C reduced α-helical content (67.82%) and increased the β-sheet content (33.15%), which resulted in the greater stabilization of the oil-water emulsion (1.29-fold), enhanced foaming capacity (2.08-fold) and improved the solubility (1.23-fold). The fluorescence quenching in SC-CO2 treated PKPIs confirmed the conformational change in protein structure. A significant variation in denaturation temperatures (74.53–66.20 °C) and enthalpy values (133.16–93.98 J/g) of SC-CO2 treated PKPIs, indicates protein denaturation and the formation of new intermolecular bonds between proteins molecules. Furthermore, SC-CO2 treatment reduced the particle size and exerted a greater homogeneity, thereby offering new opportunities to extend its use in food applications.