The effect of temperature and shear upon technological properties of whey protein concentrate: Aggregation in a tubular heat exchanger

Microparticulation of whey proteins at low concentration (2%, w/v), was examined in a pilot plant tubular heat exchanger (THE). Turbulent flow in combination with moderate temperatures (≤85 °C) was used in the heating section to prevent fouling, whereas the flow was varied from laminar to turbulent in the holding section of the THE. The logarithm of the formal rate of denaturation of β-lactoglobulin (β-Lg) kf was −5.4 to −2.5 depending on the temperature. Variation of flow velocity in the holding section had a negligible impact on denaturation degree of β-Lg and particle size of agglomerates. A high increase of elastic modulus, G′, of agglomerates was combined with only bisection of water holding capacity. Advanced modifications of particle structure and properties are supposed to be achievable by more freedom in control of flow character at a heating section of a THE for example through application of direct heat transfer principles.