Effects of heat treatment on the emulsifying properties of pea proteins

The effects of heat treatment on the emulsifying properties of pea proteins were investigated. Thermal treatment of pea proteins at 95 degrees C for 30 min increased the extent of protein aggregation, and the hydrodynamic diameter increased with the increasing of heated protein concentration (c(h)). Electrophoresis showed that acidic and basic (AB) subunits as well as convicilin in unheated pea proteins were involved in the formation of polymers linked by disulfide bonds (SS) after heat treatment (95 degrees C, 30 min). At different protein concentrations in the continuous phase (c: 0.1%-0.5%, w/v) with constant oil fraction of 0.1, emulsions formed by heated pea proteins (95 degrees C, 30 min) showed higher protein adsorption percentage and creaming stability than those formed by unheated proteins. Proteins adsorbed at the oil-water interface contained higher percentages of vicilin and basic subunit of legumin (leg B) in emulsions stabilized by heated pea proteins than in those stabilized by unheated proteins. Moreover, increasing c was conducive to the formation of emulsions with greater stability against creaming. In addition, emulsion viscosity increased with the increasing of c(h). These results indicated that the heated pea proteins, as compared to the unheated pea proteins, exhibited a greater potential to act as a kind of excellent emulsifiers. (C) 2015 Elsevier Ltd. All rights reserved.