Chemical and physicochemical features of common plant proteins and their extrudates for use in plant-based meat

Demand for plant-based meat is increasing as the flexitarian diet becomes popular. Many meat analog products in the market are made from soy and wheat proteins, but other protein sources can be used. Alternate legume proteins can be an economically and functionally viable option. This review discusses qualities of traditional meat analog proteins (soy and wheat gluten), pea protein, and emerging pulse proteins (chickpea, faba bean, lentil, mung bean). Raw traits of protein are important for texturization via extrusion. This review focuses specifically on protein sedimentation coefficients, amino acid composition, least gelation concentration, denaturation temperature, water and oil absorption capacity, viscosity and flow temperature. Product qualities (protein solubility, water holding capacity, amino acid composition, digestibility and texture) of meat analogs based on various protein sources are also discussed. Physicochemical properties of each protein should be considered before extrusion, as their functionality can vary even when from the same botanical source. The analysis and methods used for transitioning from soy and wheat gluten to pea can be useful in the utilization of additional pulse proteins. The quality of pea based textured vegetable protein is heavily dependent on processing parameters such as specific mechanical energy, moisture, and temperature. However in general, pea protein based texturized products have a lower cutting strength, and less chewiness than soy or gluten based products due to differences in protein sub-units and also cold and hot water swelling (or gelling) properties that can be potentially manipulated by using functionality modifiers.