Effects of pH and Salt Concentration on Functional Properties of Pumpkin Seed Protein Fractions

Abstract

In this study, albumin, globulin and glutelin concentrates with the protein contents of 70.4%, 77.9% and 72.3%, respectively were isolated from deffated pumpkin seed meal. Evaluation of functional properties revealed that water absorption capacity of glutelin was always higher than that of globulin while albumin exhibited the lowest water absorption capacity. Albumin showed the highest oil absorption capacity (6.90 mL/g), followed by globulin (3.00 mL/g) and glutelin (2.27 mL/g). In the pH range 2–10 or salt concentration range 0–1 M, albumin demonstrated the highest foaming properties. Glutelin had the best emulsifying capacity at low pH (2–3). In distilled water, the least gelation concentration of albumin and glutelin was similar (14%) and lower than that of globulin (16%). pH adjustment or salt addition could improve functional properties of the three protein concentrates. Pumpkin seed proteins could be used as good protein ingredients in formulation of new food products. Practical Applications In this study, albumin, globulin and glutelin concentrates were prepared from defatted pumpkin seed meal. The effects of pH and salt concentration on functional properties of the pumpkin seed protein fractions were reported. The investigated functional properties included water and oil absorption capacity, emulsifying capacity, emulsion stability, foaming capacity, foam stability and gelation capacity. The obtained results would be useful for food researchers who look for new protein source as functional ingredient in new food product development.