Physicochemical and techno-functional properties of acid-aided pH-shifted protein isolate from over-salted duck egg (Anas platyrhucus) albumen

Here, potential physicochemical and techno-functional properties of the albumen protein recovered from over-salted albumen by an effective acid-aided pH-shift process (POA) were tested in comparison with the fresh albumen (FA) and albumen protein recovered from fresh albumen by acid-aided pH-shift process (PFA). POA contained 66.73% protein and 11.30% sodium (dry basis). Surface hydrophobicities of PFA and POA were higher than FA (P < 0.05), whereas the reactive sulfhydryl content of FA was higher than PFA and POA (P < 0.05). PFA had the highest whiteness followed by POA and FA, respectively. Single endothermic peak in DSC thermogram was found at 86.86, 89.67 and 98.96 °C for FA, PFA and POA, respectively. Long-term salting impaired the solubility, viscosity, emulsifying activity and gelation but not for foaming of albumen protein isolate. FA can be softly gelled with continuously packed structure, whereas PFA and POA underwent agglutination to form white clot suspension with spongy network.