Impact of native pea proteins on the gelation properties of pea protein isolates

Pea protein isolates (PPI) mainly contain globulin proteins responsible for forming fragile gels affecting the texture properties of plant-based foods like extruded meat analogs. This study aims to extract a soluble protein fraction (SPF) from air-classified pea protein concentrate (PPC) containing globulins and albumins and use it directly in its liquid form to enhance the elasticity of PPI gels and extrudates produced by high moisture extrusion (HME). Two commercially available PPIs and one PPC were characterized by protein solubility, differential scanning calorimetry, and heat-induced gelation capacity by rotational rheology. Gel characterization was done by small amplitude oscillation rheology. Protein extraction at concentrations between 5% and 10% w/w and mildly alkaline pH was the most efficient way to produce functional SPF with high protein yield (> 67%). The SPF had a positive effect on the yield strain of PPI gels. However, the effect on the elastic modulus (G’) depended on the degree of protein isolate purification. Moreover, adding SPF directly as wet feed in HME reduced the brittleness of PPI extrudates. This research highlights the texture formation potential of minimally pre-processed pea protein ingredients in plant-based foods (e.g., meat analogs) manufactured with HME.