Effect of ozone, H2O2 and organic solvents on tannin content of Persian gum: Investigation of physicochemical properties

The major challenge regarding Persian gum (PG) is its tannin content which acts as an anti-nutritional compound by binding to ions and proteins. Therefore, the effect of H 2 O 2 , ozone gas, and organic solvents on tannin removal of PG was investigated. For this purpose, PG was treated with H 2 O 2 and ozone at different concentrations. Moreover, organic solvents were applied at ratios of 1:10, 1:20, and 1:30 when PG was used in powder form, and at ratios of 1:2, 1:3, and 1:4 when the solvents (ethanol and acetone) combined with PG in dispersion form. Based on the results, the H 2 O 2 -treated sample exhibited the lowest a∗ and b∗ values, as well as the highest L∗, indicating its effectiveness in causing color fading. The appropriate solvent for tannin removal of PG in dispersion form was ethanol at the ratio of 1:2, while for PG in powder form, acetone at the ratio of 1:10 showed the best results. Tannin removal reduced the apparent viscosity, and the highest zeta potential belonged to the ethanol-treated sample (−29.95 mV). FTIR analysis indicated that –COOH groups of H 2 O 2 -treated PG remained undissociated; hence, this sample can be used where PG is intended to function as a non-adsorbing gum. • Acetone was the best solvent for tannin removal of Persian gum in powder form. • Ethanol was the most effective solvent for tannin removal from Persian gum dispersion. • The lowest a∗ and b∗ values belonged to the H 2 O 2 -treated Persian gum. • Treating at pH 3 and 20 °C was the best condition for tannin removal with H 2 O 2 (0.5 M). • Tannin removal treatments diminished apparent viscosity and zeta potential of Persian gum.