Functional characterizations of sodium caseinate conjugated with water-soluble bitter almond gum exudate

Abstract

This study investigated the impact of incubation time (1, 2, 4, and 7 days) on the functionality of sodium caseinate (SC) conjugated with the water-soluble fraction of bitter almond gum (SBAG) (1:2) under a controlled Maillard reaction. SDS-PAGE confirmed the conjugation between two biopolymers. The thermal stability of SC improved remarkably from ∼73 °C to 83 °C with the increasing incubation time up to 2 d The fluorescence intensity declined due to changing SC conformation. The conjugate prepared under 2 d incubation showed the highest viscosity and viscoelastic moduli. The solubility was improved with increased incubation time (from approximately 42.25% to 55.72%), whereas water holding capacity was not affected up to 4 d incubation (44.75±3.15% vs. 46.35±2.25%). A significant improvement in emulsifying, foaming, and radical scavenging activities was detected with the incubation time (from ∼68.2 to 190.5 m2/g, 40.85 to 97.55%, and 4.9 to 46.5%, respectively). However, prolonged incubation negatively affected some conjugate properties, including WHC, emulsion, and foam stability. Overall, the results suggest that an incubation period between 2 and 4 days could be desirable to improve most glycated SC attributes, allowing it to perform better in food applications.