Influence of κ-carrageenan on the aggregation behaviour of proteins in heated whey protein isolate solutions

The influence of the addition of κ-carrageenan to 2% whey protein isolate (WPI) at pH 7 and heated at 75 °C for different times, has been investigated by size-exclusion chromatography with multi-angle laser light scattering and gel electrophoresis. Under the conditions used, the addition of κ-carrageenan to WPI did not influence the loss of native β-lactoglobulin or α-lactalbumin. However, κ-carrageenan addition affected the molecular weight (Mw) of the aggregates formed by the heat treatment. The Mw of the whey protein aggregates formed in the early stages of heating in the presence of κ-carrageenan were lower than the aggregates formed in WPI solutions heated in the absence of κ-carrageenan. At longer heating times, the Mw of the aggregates in the WPI/κ-carrageenan mixtures were similar to the Mw of the aggregates in the WPI solutions heated alone.