The effect of limited hydrolysis followed by glycation with galactose, and vice versa, on interfacial and foaming (foamability and foam stability) properties of β-lactoglobulin (β-Lg) at pH 7 and pH 5 has been studied. Hardly any effect of the two treatments, hydrolysis and glycation (HG) or glycation and hydrolysis (GH), on the β-Lg foaming capacity at both pH values was observed. Foam stability, however, was significantly enhanced after both HG and GH at pH 5. Particularly, the system obtained after glycation at 50 °C followed by limited hydrolysis showed an exceptional stability, which might be related to the increase in elastic character and cohesion of the interfacial film, indicated by the increase of the surface dilatational modulus (E) and the decrease of the phase angle (ϕ) over the time. These results indicated that glycation of β-Lg with galactose followed by limited hydrolysis might allow extending the use of this protein as foaming agent, although further research in complex food systems is needed to apply this method in the formulation of acidic foods and beverages.
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