Comparison of functional properties of commercial plant protein isolates and sonication pretreatment assisted extraction-based plant protein isolate blends

The current study was conducted at ICAR-Indian Agricultural Research Institute, New Delhi, India, in the year 2023. Plant Protein Isolates (PlPIs) derived from sesame, mung bean, peanut, chickpea and spirulina have attracted widespread attention due to their high nutritional value, the popularization of vegan diets and broad availability. However, their relatively poor functional properties compared to animal proteins limit their wider use in food formulations. This study investigates the effect of sonication pretreatment on the functional properties of lab-made PlPI blends compared to Commercial Plant Protein Isolates (CPlPIs). Functional attributes such as solubility, dispersibility, swelling capacity, foaming and gelation behaviour were evaluated. PlPI blends exhibited significantly higher solubility (up to ~48 % at pH 11) and oil-holding capacity (~339 %) than commercial isolates. Dispersibility in PlPI blends ranged narrowly from 61–63 %, whereas CPlPIs varied widely between 16 % and 100 %, depending on formulation. Swelling capacity was also notably improved in PlPI blends (13.3–426.9 %) compared to CPlPIs (12.1–122.2 %). Rheological analysis (flow properties) indicated shear-thinning behaviour (less viscous when stirred or subjected to force) for both PPI-blends and CPPIs, with PPI-blend 2 showing the highest viscosity due to its greater swelling capacity. PPI-blends demonstrated higher oil-holding capacity (330.6–339.7 %) than CPPIs (66.7–139.5 %). However, unlike CPlPIs, which formed gels at low concentrations (1–3 %), all PlPI blends required a higher concentration (12 %) to gel. This is the first study to systematically compare sonicated PlPI blends with CPlPIs across multiple functional traits using diverse plant sources. Overall, sonication pretreatment improved hydration and functional properties, making sonicated PlPI blends promising ingredients for developing plant-based dairy alternatives, meat analogues and other functional food products requiring improved solubility, foaming and texture.