Attenuated total reflection Fourier transform infrared spectroscopy was used to compare the structure of β-lactoglobulin, basil seed gum, and β-lactoglobulin-basil seed gum mixtures, at different states (powder, solution, and gel). The effects of heating and different ratios of β-lactoglobulin-basil seed gum were also investigated to determine their impact on chemical structure and understand their interaction. The results showed that gelification process proved a pronounced effect upon β-lactoglobulin secondary structure, leading to the formation of intermolecular hydrogen-bonding β-sheet structure. These results confirmed that this structure may be necessary for the formation of a gel network. Basil seed gum had a distinct peak at around 1603 cm–1 that relates to –COO–1 stretching of carboxylate salts, probably uronic acids, which approved its anionic structure. The Fourier transform infrared spectroscopy findings strongly suggested that these two polymers are thermodynamic incompatible as amide I peak was increased in the β-lactoglobulin-basil seed gum mixed system and carbon–nitrogen (CN) stretching peak was observed at 2125 cm–1. On the basis of these findings, it was possible to modify the ability of β-lactoglobulin-basil seed gum to form a gel and as a consequence to control the gelling and emulsifying properties.

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