Flow process and heating conditions modulate the characteristics of whey protein aggregates

Whey protein fractal aggregates reveal different texturizing properties depending on their size. This study characterize the effect of three process parameters (flow regime, heating residence time (RTh) and heating temperature) on the size and shape of aggregates formed at a semi-industrial scale using a dynamic tubular heat exchanger, and identify the mechanisms involved in their formation. The study showed that physicochemical parameters are not the unique levers to modulate agregates properties but process parameters are also efficient. Asymetrical-Flow-Field-Flow-Fractionation was used to highlight the significant increase of aggregate size produced under transient regime conditions compared to laminar and turbulent regimes. Even larger aggregates were obtained while increasing the heating temperature from 80 to 85 °C since the unfolding aggregation of protein was controlled by the aggregation step. Moreover, RTh showed no effect on aggregate formation. This study paves the way to the control of aggregate properties obtained in a continuous dynamic mode.