Tailoring the structure-functionality and volatile properties of pea protein isolate by high-pressure homogenization: Impact of pass number and pressure.

Abstract

Pea protein is increasingly used in food formulations due to its nutritional value and sustainability. However, its limited solubility, weak interfacial properties, and undesirable off-flavors remain major constraints for broader application. In this study, pea protein isolate (PPI) was subjected to multi-stage high-pressure homogenization (HPH) at pressures ranging from 100/1000 psi to 500/5000 psi with various pass numbers (1, 2, and 3) to examine how processing intensity affects its structural, functional, and volatile properties. SDS-PAGE showed no detectable changes in molecular weight distribution, whereas FTIR, particle size distribution, and zeta potential analyses collectively indicated that HPH induced subtle physicochemical modifications in PPI. These modifications improved functional properties, particularly solubility, which increased from 83.18% in the untreated sample to 88.14% under optimized conditions. Enhancements in foaming capacity and emulsifying activity were also observed, most prominently at 500/5000 psi, although excessive processing resulted in a slight decline in foaming performance. In contrast, emulsifying stability remained largely unchanged across conditions. Furthermore, GC-MS was used to evaluate the changes in the volatile profile of PPI after HPH treatment. Seven major compounds dominated by lipid oxidation products were identified. Their relative abundances varied with homogenization conditions with pressure exerting a more pronounced influence than pass number. Overall, HPH effectively tailored the properties of PPI by reducing particle size, improving solubility and interfacial properties, and altering its volatile profile, although at higher homogenization pressures the potential trade-off between functionality and oxidative flavor stability needs to be considered.