Effects of microfluidization and transglutaminase cross-linking on the conformations and functional properties of arachin and conarachin in peanut

Functional properties of food protein can be modified by appropriate modification technology, which enable food proteins to have a abroad range of application in the food industry. In the present study, arachin and conarachin fractions of peanut protein were treated by microfluidization treatment (MT, 120 MPa) and/or transglutaminase (TGase) cross-linking (TC). We investigated the effects of these different treatments on the conformations and functional properties of arachin and conarachin. The results showed that both MT and TC could effectively unfold the structures of proteins along with increasing the exposed free SH contents and surface hydrophobicity (H0), and improve the emulsion stability. Interestingly, microfluidization was more effective in improving the functional properties (e.g., solubility or emulsifying properties) of arachin and conarachin than TGase cross-linking. Moreover, it was found that microfluidization pretreatment could facilitate TGase-induced cross-linking of arachin/conarachin. Compared with individual treatments, combined treatments could yield more unfolded protein structures of arachin/conarachin. In addition, the combined treatments could remarkably improve the emulsion stability for arachin and conarachin in comparison with individual MT, and also significantly enhanced the protein solubility and emulsifying activity compared with TC.