Rheological and interfacial properties of basil seed gum modified with octenyl succinic anhydride

This study aimed to evaluate rheological and interfacial properties of basil seed gum (BSG) esterified with octenyl succinic anhydride (OSA) at different OSA:BSG weight ratios (WRs) of 0, 0.01, and 0.03. The amounts of added OSA were analyzed by high performance liquid chromatography (HPLC) and ion mobility spectroscopy (IMS). The high correlation coefficient (R-2 = 0.998) between the results of HPLC (0%, 0.277%, and 1.01%) and IMS (0%, 0.31%, and 0.97%), obtained at different WRs, indicated that IMS can be considered as an alternative analytical technique for HPLC to determine the extent of modification. The entropy (image information content) of scanning electron micrographs of lyophilized BSG was decreased after modification and attributed to relative disappearance of spherical particles and formation of a structure with higher integrity. A decrease in interfacial tension, an increase in contact angle and molecular weight, and more negative values of zeta-potential were recorded after modification. All dispersions showed shear-thinning behavior with an increase in apparent viscosity after modification. The first-order stress decay with a non-zero equilibrium stress was better than other models for predicting the thixotropic properties. The dilute solution properties were better fitted with slope-based models than intercept-based models. A dominant elastic behavior was observed in BSG dispersions and corresponding BSG-stabilized emulsions and improved after modification. The OSA-modified BSG exhibited an improvement in the emulsifying and foaming capacities and colloidal stability over time. Emulsions prepared with modified gums showed a smaller droplet size. OSA-modified BSG might be a good candidate for improving the long-term stability of emulsions.