The occurrence of a Maillard-type protein-polysaccharide reaction between β-lactoglobulin and chitosan

Reaction mixtures containing β-lactoglobulin and chitosan (1:4 weight ratio) were dry-heated at 40 °C and 79% relative humidity for 2 weeks. Absorbance measurements and SDS-PAGE analysis indicated the occurrence of the Maillard reaction and conjugate formation, respectively. Some β-lactoglobulin and chitosan properties were modified. For example, the emulsifying capacity at pH 4 and bactericidal activity against Escherichia coli of the Maillard reaction products (MRPs) increased with incubation period up to 2 days, after which these properties deteriorated. The latter was explained by MRPs degradation, which was confirmed by the increased appearance of degradation products in electrophoresis gels at longer incubation times. Data show that the Maillard reaction, under the studied conditions, can be successfully employed to generate MRPs from β-lactoglobulin and chitosan, which exhibit improved properties with respect to β–lactoglobulin alone.