Rheological, structural and physicochemical characteristics of heat-induced egg albumin/sesbania gum mixed gels

The effects of sesbania gum (SG) on the rheological and physicochemical properties of heat-induced egg albumin gels were investigated. The formation of the gels of egg albumin (4%, w/v)/SG (0, 0.1, 0.2 and 0.3%, w/v) mixtures were induced by heating. It was evident from the appearance of gels' microstructure that phase separation occurred in egg albumin/SG systems. Non-Newtonian pseudoplastic flow behavior was observed in all the gels and it was further evident that 0.1% of SG could significantly (p < 0.05) improve the apparent viscosity of the egg albumin gels. The rheological characteristics of the gels demonstrated a more stable and plastic character gel formed at 0.1% SG. The temperature stability test showed that the structures of egg albumin/SG gels maintain their stability when reheated. The hardness of the egg albumin gels was improved with the addition of 0.1% SG, and their water holding capacity (WHC) was also improved. For egg albumin gel with 0.1% SG, a three-dimensional stranded network was observed, indicating the formation of a more stable and tight gel. The FTIR results confirmed that egg albumin and SG are thermodynamically incompatible, which suggested that there is no covalent bonding between egg albumin and SG.

Keywords: Egg albumin; Heat-induced gels; Physicochemical properties; Rheological properties; Sesbania gum.