Adsorption properties of ovalbumin (OVA) as emulsifier in water-commercial oil systems

Abstract

Emulsions are widely used metastable materials which wide applications in field of food and pharmaceutical industries. The present study focuses on understanding the adsorption behavior and emulsifying properties of a globular protein Ovalbumin (OVA) in water and three different commercial oils: Corn Oil (CO), Olive Oil (OO) and Soybean Oil (SBO) emulsions. Concentration of the emulsifier is a major influencing parameter in the formulation of emulsions. So we have conducted our study using variable concentration of OVA and carried out visual observations to see effect. Upon the revelation of destabilization, the turbidimetric analysis has been done to quantify the rate of destabilization. To estimate the adsorption of protein at the oil-water interface the dynamic interfacial tension (IFT) are done and an effective diffusivity has been calculated which indicate clear influence of OVA concentration. The Serrien model fitting of obtained data is done to better understand the mechanism of OVA adsorption which reveals that diffusion is a more prominent phenomenon than the rearrangement influencing the reduction in IFT. The microscopic analyses of the cream and serum phases of the emulsion also show variation in droplet density. The dense and jammed droplet packing of the oil droplets in the cream phase indicates towards depletion flocculation. The rheology of the cream phase shows that with increase in the OVA concentration the storage modulus (G?) and loss modulus (G??) increase as a result of lower oil droplet size as observed in the microscopic analysis.