Whey proteins are usually sensitive to ionic strength, pH change, and heat treatment, which may affect their functional properties. Maillard conjugation could be a facile approach to improve whey protein functionality. In this study, whey protein isolate (WPI; 0.6%, w/v) was conjugated to low acyl gellan gum (0.1, 0.2, and 0.3%, w/v) through the Maillard reaction at 90 C for 90 min. The conjugate formation was confirmed by pH decrement, glycation degree (up to 9.44%), browning index, sodium dodecyl sulphatepolyacrylamide gel electrophoresis, and Fourier transform infrared spectroscopy. The surface hydrophobicity of WPI increased up to 2-fold upon conjugation, which led to a solubility decrease. However, the conjugated WPI had an improved interfacial activity, emulsifying activity (~6%), foaming capacity (up to 63.64%), thickening ability (up to 24.67-fold), reducing power (up to 28.86-fold), and iron chelating activity (up to 3.31-fold). These findings may widen the industrial application of whey proteins.

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