Comparative Assessment of Thermal Aggregation of Whey, Potato, and Pea Protein under Shear Stress for Microparticulation
Caren Tanger, Paola Quintana Ramos, Ulrich Kulozik
Abstract
The presented work investigates the aggregation behavior of whey, pea, and potato proteins under a shear stress using a rotational rheometer. The size, protein interaction, and morphology of the aggregates were analyzed. Whey protein particles were cross-linked by disulfide bonds (75%–90%). In contrast, potato protein particles were cross-linked by a hydrophobic interaction (88%–97%). High shear rates were needed to limit the aggregate growth. Pea protein particles were stabilized in equal parts by hydrophobic interactions (40%–62%) and disulfide bonds (37%–56%) in equal parts. Aggregate size was dependent on the processing history of the protein. Native pea protein favored a particle size of 5–30 μm and was independent of the shear rate. An increasing shear rate decreased the aggregate size of preaggregated pea protein to a d50 of 29 μm. A general prediction of the protein aggregation behavior based on the molecular structure remains a challenging task. This research provides insights into the aggregation behavior of pea and potato proteins and helps to design microarticulated structures of plant proteins.