Controlled food protein aggregation for new functionality

Globular proteins are an important component of many food products. Heat-induced aggregation of globular proteins gives them new properties that can be useful in food products. In order to optimize functionality, the aggregation process needs to be controlled, which in turn requires good understanding of the mechanism. Heating aqueous solutions of globular proteins leads to the formation of aggregates with one of four distinctly different morphologies: spherical particles, flexible strands, semi-flexible fibrils, and fractal clusters. We review recent research in this area focusing on the parameters that control the morphology including the influence of hydrolysis. The aggregation mechanism and the effect of the morphology on the functionality will be addressed. A distinction is made between primary aggregation leading to roughly spherical particles or more or less flexible strands and secondary aggregation leading to fractal clusters, gels or precipitates. We will discuss how the formation of aggregates with different morphologies is related to the formation of either particulate or fine stranded gels.