Effect of Thermal Treatment on Chemical Structure of B-Lactoglobulin and Basil Seed Gum Mixture at Different States by ATR-FTIR Spectroscopy

Attenuated total reflection Fourier transform infrared spectroscopy was used to compare the structure of -lactoglobulin, basil seed gum, and -lactoglobulin-basil seed gum mixtures, at different states (powder, solution, and gel). The effects of heating and different ratios of -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 -lactoglobulin secondary structure, leading to the formation of intermolecular hydrogen-bonding -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 -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 -lactoglobulin-basil seed gum to form a gel and as a consequence to control the gelling and emulsifying properties.