d-psicose (Psi), a rare ketohexose, improves food properties of proteins through the Maillard reaction (MR) much more than d-fructose (Fru). This encouraged us to investigate the improvement of food properties of proteins through MR with various rare ketohexoses (d-psicose, Psi; d-tagatose, Tag; and d-sorbose, Sor). The food properties of egg white protein (EWP) after reaction with Psi, Tag, Sor and Fru were studied. Psi-EWP (43.3 μmol TE g−1) and Tag-EWP (43.4 μmol TE g−1) had the highest antioxidant activity, followed by Sor-EWP (38.4 μmol TE g−1) and Fru-EWP (38.9 μmol TE g−1). MR enhanced the breaking stress of heat-induced EWP gels by 224–267%. The breaking stress was higher in Psi-EWP (81.1 kN m−2), Tag-EWP (80.0 kN m−2) and Sor-EWP (77.8 kN m−2) than in Fru-EWP (71.6 kN m−2). Furthermore, the foaming capacity was highest in Psi-EWP and Sor-EWP. Rare ketohexoses improved food properties of EWP more than Fru. Overall, Psi offered the greatest functional improvement.Summary
Food properties of egg white protein were improved through Maillard reaction with D-ketohexoses. Antioxidant activity and gelling properties were improved more by D-psicose and D-tagatose, while emulsifying and foaming properties were improved more by D-psicose and D-sorbose. Overall, D-psicose offered the great functional improvement.