Food properties of egg white protein modified by rare ketohexoses through Maillard reaction

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 mu mol TE g(-1)) and Tag-EWP (43.4 mu mol TE g(-1)) had the highest antioxidant activity, followed by Sor-EWP (38.4 mu mol TE g(-1)) and Fru-EWP (38.9 mu mol 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.