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

Abstract

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 ( M w) of the aggregates formed by the heat treatment. The M w 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 M w of the aggregates in the WPI/κ-carrageenan mixtures were similar to the M w of the aggregates in the WPI solutions heated alone.