Influence of pH on fluid gels produced from egg and whey protein isolate

Abstract

Food producers are coming under increasing pressure to reduce fat content of foods. Fat forms a major structuring component in many foods responsible for the desirable texture of foods which are rich in fats. Consumers want healthier foods whilst maintaining desirable sensory properties of these foods and using ‘natural’ ingredients. In this work we present suspensions of soft gelled protein particles produced by heating induced gelation in shear of proteins. We present egg white fluid gels and compare them with previously characterized WPI fluid gels. Understanding the effects of pH on proteins is important owing to the net charge influencing gelation and gel properties. Soft tribology and rheology were used to investigate textural properties of fluid gels produced and relate these to potential mouthfeel of these systems. Fluid Gels at the IEP were shown to produce aggregated particles of less than 1 μm diameter. These systems produced at the IEP demonstrated greater friction values in the mixed and boundary regimes of lubrication.