Abstract
Probe spectrofluorimetry studies for ovalbumin (OVA) show an increase in surface hy-drophobicity at pressures > 400 MPa. Pressure treatment of mixtures of OVA+ dextran sulphate (DS) greatly reduces the surface hydrophobicity. Size exclusion chromatography data indicate that stronger protein-polysaccharide complex(es) are formed during treatment at low ionic strength and pH 6.5. Emulsions made with pressurized (600 MPa) OVA in the presence of polysaccharide at pH 6.2 and low ionic strength exhibit the improved emulsifying efficiency and stabilizing properties of the protein. Under pressure treatment at pH ≤ 6.5, OVA forms reversible electrostatic complex(es) and the strength of interaction is related to the charge density on the polysaccharide (DS > Ltarrageenan (t-CAR) > κ-carrageenan (κ-CAR)). Complexation of OVA with polysaccharide seems to protect the protein against loss of functionality from pressure-induced aggregation.