Functionalised plant protein powders: From phase separation to particulate isolates
Nirzar Doshi1, Sai Krishna Keshava Reddy2, Laurice Pouvreau3
1Laboratory of Physics and Physical Chemistry of Foods, Wageningen University and Research, Wageningen, The Netherlands; Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Wageningen, The Netherlands.
Abstract:
Achieving high protein levels in plant-based foods is limited by viscosity, poor dispersibility, and protein aggregation at elevated concentrations. Residuals, such as lipoxygenase, albumins, and antinutritional factors, also impair flavour and nutrition. Addressing these issues requires functional, scalable ingredient formats. In this work, we present a process-compatible strategy using liquid-liquid phase separation (LLPS) to produce globulin-rich protein particles under mild conditions, aligned with existing wet extraction workflows. Using yellow pea protein as a model system, we generated a particulate protein isolate through spontaneous LLPS at pH 4.5, followed by heat treatment, purification, and spray drying. The resulting powder contained 81 % protein (w/w, dry basis), with marked globulin enrichment and significant removal of albumins, lipids, sugars, and soluble polysaccharides-components associated with viscosity, off-flavours, and poor digestibility. Colloidal dispersions of the isolate enabled spray drying at higher solids concentrations than a commercial-like control, demonstrating improved processability. Together, these results establish a scalable route to high-performance plant protein ingredients for concentrated food applications. The colloidal protein isolates readily rehydrated and formed stable, low-viscosity dispersions across a pH range of 5.0-7.0 and during 4 °C storage for up to 7 days, maintaining a lower viscosity than the control under both ambient and heated (90 °C) conditions, even at a 20 % w/w dry matter concentration. These properties support higher protein loading while retaining flowability, making the approach particularly relevant for applications such as ready-to-drink nutritional beverages and protein-fortified medical feeds. Rather than relying on solubility, this method leverages pre-structured protein particles to enhance processability under conditions where conventional isolates typically fail.
