Assessment of interfacial and foaming properties of bovine sodium caseinate glycated with galactose

The impact of the initial and advanced stages of glycation of sodium caseinate (SC) with galactose on the interfacial and foaming properties has been investigated at pH 7 and 5. At pH 7, the most remarkable result was the higher stabilizing foam capacity of glycoconjugates as compared to native and heat treated SC, as a result of the higher elastic character and cohesion of the interfacial film formed by glycated SC. At pH 5, native and control heated SC underwent a significant loss of solubility, resulting in a worse dynamic of adsorption at the interface of such systems and the formation of fluid and poorly resistant films. However, solubility of glycated SC remained relatively high, so that, at this pH, only SC glycoconjugates showed interfacial characteristics suitable to stabilize the foam during its formation as well as against mechanisms of foam destabilization at long term. This behavior was attributed to the higher adsorption efficiency and degree of interfacial interaction exhibited by the SC glycoconjugates. These findings highlight the beneficial effect of glycation on the foaming properties of SC which could contribute to broadening the applicability of SC as a foaming agent, mainly in acid foods.