Improving the colloidal stability and emulsifying property of flaxseed 11S globulin by heat induced complexation with soy 7S globulin

Abstract

Flaxseed protein contains mainly 11S globulin (FG). It suffers significant aggregation upon heating, ionic strength and pH variation which hinders its application in food products. This study aims at improving the colloidal stability of FG by fabricating a flaxseed 11S globulin-soy 7S globulin (SG) complex and exploring its potential application in stabilizing emulsion. Results showed that SG could limit the thermal aggregation of FG by forming a stable FG-SG complex above 80 °C at neutral pH. Increasing temperature and heating time would promote the exposure of hydrophobic sites and facilitate the complexation that was irreversible. The complex showed enhanced stability against ionic strength and pH variation and was able to stabilize high internal phase emulsion (HIPE) with oil volume fraction up to 85% by a minimal protein concentration of 20 g/L which however could not be achieved solely by flaxseed 11S globulin. The HIPEs showed long term stability in a wide range of pH and ionic strength. This study paves way for enhancing the functionalities of oilseed 11S globulin simply through thermal induced complexation with 7S globulin from another plant source.