Effect of Metal Ions on The Functional Properties of Taro Protein Isolate

This study investigated the effects of metal ion species and concentrations on the functional properties of taro protein isolate (TPI), extracted from Colocasia esculenta corms. The results demonstrated that metal salt solutions could modulate the unfolding and aggregation of TPI, thereby altering its protein-protein and protein-water interactions and significantly affecting the functional properties. When monovalent cation concentration [M⁺] was less than or equal to 60 mmol/L or divalent cation concentration [M²⁺] was below 40 mmol/L, the concentration increasing of metal ions enhanced the solubility of TPI, while reducing the foaming capacity and foam stability, and improving the emulsifying capacity and emulsifying stability. When [M⁺] was higher than 60 mmol/L or [M²⁺] was higher than 40 mmol/L, the solubility of TPI decreased due to partial aggregation, and the foaming capacity and foam stability exhibited antagonistic characteristics, while the emulsifying capacity increased (except for Na⁺), and the emulsifying stability decreased. It was worth noting that molecular aggregation involving Ca²⁺ significantly reduced T_gel of TPI solution and markedly enhanced the gel strength.