Functional Properties of Water-soluble Proteins from Silver Carp (Hypophthalmichthys molitrix) Conjugated with Five Different Kinds of Sugar

Water-soluble proteins (WSP) from silver carp denature easily during thermal processing, leading to the reduction of functional properties. In order to improve the functional properties of WSP and to utilize its resources efficiently, five different kinds of sugars (i.e., xylose, glucose, galactose, oligo-isomaltose, and dextran-10) were used to conjugate with WSP by Maillard reaction. Results suggested that the use of the Maillard reaction improved the solubility, heat stability, and emulsifying properties of WSP. With the increase of molecular weight (MW) of the sugars, the solubility, emulsifying properties, and total sulfhydryl (SH) groups of WSP increased, while the surface hydrophobicity decreased. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of the five Maillard reaction products (MRPs) showed that xylose reacted easily with WSP than did the other four kinds of sugar. Dextran-10 conjugated to WSP could efficiently improve the functional properties of WSP during heat processing.