Functional improvement of whey protein concentrate on interaction with pectin

The formation of a protein–polysaccharide soluble complex is a valuable method for determining the physico-chemical properties of proteins. The present work was undertaken with the objectives of preparation of whey protein concentrate (WPC)–pectin complexes and to evaluate the functional properties at different conditions, viz., pH, salt and temperature. WPC–pectin complexes were prepared by dry heat treatment and the complex formation was ascertained by gel filtration (using G-100) and centrifugation techniques. Studies on the functional properties of this protein–polysaccharide complex showed increased solubility at pH 4.6 compared to the control ultrafiltered whey protein concentrate (UF WPC). Emulsifying properties were also observed to be higher, viz., 98.56% emulsion activity at 0.10% concentration and 99.65% emulsion stability at 0.25% concentration. Better gelation was observed in UF WPC–pectin complexes at 8% concentration compared to UF WPC alone. Foaming properties were also observed to be improved in these complexes at pH values (4.6 and 7) and temperature (10 and 30°C), whereas, increased foam stability was observed at 1.0 M ionic strength.