Effect of Xanthan, Guar, and Carrageenan Gums on the Physicochemical Properties of Hypoallergenic Pea Protein-Based Dysphagia-Friendly Matrices

Due to the allergenicity of soy protein, this study aimed to develop a hypoallergenic, dysphagia-friendly matrix using pea protein isolate. We investigated the effects of three hydrocolloid thickeners-xanthan gum (XG), guar gum (G), and carrageenan (C)-at various concentrations on the matrices' rheological properties, textural characteristics, and dysphagia diet classification. The unthickened pea protein base was unstable, exhibiting rapid phase separation and low viscosity, unsuitable for dysphagia diets. The addition of XG (0.4-0.6 g), G (0.5-1.0 g), and C (0.8-1.2 g) successfully produced food matrices meeting the slightly, mildly, and moderately thick levels of the Japanese Society of Dysphagia Rehabilitation (JSDR) framework. However, discrepancies were noted between instrumental viscosity and syringe flow test classifications. Rheological analysis revealed that XG samples were in elastic (<i>G</i>' > <i>G</i>″) domain in the linear viscoelastic region (LVR) and exhibited shear-thinning behavior. In contrast, G and C samples were in viscous (<i>G</i>″ > <i>G</i>') domain. Frequency sweeps characterize XG samples as weak gels, G samples as dilute polymer solutions, and C samples as gel-like structures. Texture profile analysis further showed that xanthan gum imparted the highest firmness and thickness, whereas guar gum provided the best flowability.