Characterization and emulsifying properties of β-lactoglobulin-gum Acacia Seyal conjugates prepared via the Maillard reaction

Gum Acacia Seyal (ASY) is less valued than is gum Acacia Senegal, due to its poor emulsifying ability. The present study investigated the Maillard reaction between ASY and β-lactoglobulin (BLG) and its impact on the emulsifying properties of ASY. The reaction products of BLG/ASY mixture (r = 1/4), prepared by dry-heating at 60 °C and a relative humidity of 79%, as a function of incubation time, were characterized by SDS-PAGE, GPC-MALLS and DSC. The results showed that 12-24 h of dry-heating under the given conditions was sufficient for conjugation, meanwhile avoiding the formation of deeply coloured and insoluble melanoidins. More than 64% of the protein was incorporated into ASY, resulting in a two-fold increase in arabinogalactan-protein (AGP) content and 3.5 times increase in weight-average molecular mass of ASY. The conjugation with BLG markedly improved the stability of ASY-stabilized emulsions and their resistance against severe conditions, such as low pH and high saline conditions.