Abstract:The arachin/conarachin-rich fractions were isolated from defatted peanut flour by cryoprecipitation in this study. The peanut protein-rich fractions were mixed with maltodextrin in a 1:1 weight ratio. At a temperature of 60 ℃ and a relative humidity of 79%, arachin-rich and conarachin-rich fractions underwent glycosylation reactions for one to seven days and 8 to 24 h, respectively. The extent of glycosylation between peanut protein-rich fractions and polysaccharides was characterized using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the changes in the conformational properties of the glycosylation products of peanut protein isolates and polysaccharides were investigated using thermal properties and fluorescence spectra. The SDS-PAGE analysis indicated arachin/conarachin-rich fractions underwent cross-linking reaction with maltodextrin to generate macromolecular grafted products under dry-heating conditions. The subunits of conarachin-rich fraction readily underwent Maillard reaction with maltodextrin than those of the arachin-rich fraction. The thermal stability of peanut protein fractions was remarkably improved by mixing or conjugation of peanut protein-rich fractions with maltodextrin. The conformational structure of peanut protein-rich fraction became loose and subsequently compact with increasing extent of glycosylation.
