Techno-functional, rheological, and chemical properties of plant-based protein ingredients obtained with dry fractionation and wet extraction

Dry fractionation is a promising technology for producing plant protein ingredients, owing to its minimal environmental impact and adaptability to diverse plant sources. Dry-fractionated proteins are still under development with limited applications in food industry due to lack of extensive knowledge about their physicochemical, rheological and chemical properties. Wet extraction though widely used, consumes high energy, water, and chemicals. In this research, the techno-functional, rheological, and chemical properties of commercial protein ingredients of various botanical species obtained via wet extraction (WE, n = 8) and dry fractionation (DF, n = 9) were investigated in order to identify their potential food applications. Compared to DF ingredients, WE proteins showed the lowest water solubility index and protein solubility at pH 7 and 9, as well as the lowest foaming and emulsifying capacities. This behavior can be explained by the presence of denatured protein structures in WE ingredients as suggested by the analysis of the secondary structure which revealed a higher presence of random coil structures. On the contrary, the presence of non-denatured structures in combination with other constituents like carbohydrates may have contributed to the high solubility and gelling properties of the DF proteins ingredients. While wet extraction technologies can offer a wide modulation of ingredient functionality, providing a broad spectrum of food applications, dry fractionation seems to guarantee a narrow range of techno-functional properties, although with potentially higher performance in certain areas like solubility and foaming.