INTERFACIAL AND EMULSIFYING PROPERTIES OF POTATO PROTEIN HYDROLYSATES OBTAINED BY ENZYMATIC PROCESSING

Plant-based proteins are receiving growing attention as sustainable stabilizers for foams and emulsions due to their biodegradability and low cost. Moreover, their use as bio-based surfactants represents an effective approach for the valorization of plant-derived protein by-products [1]. In this context, potatoes emerge as a particularly promising resource [2]. During potato starch production, large volumes of potato fruit juice are generated as a by-product. This stream contains high concentrations of amino acids and proteins, which can be recovered by means of acidic precipitation and thermal coagulation. However, the resulting potato protein isolates typically possess limited foaming and emulsifying properties, primarily due to its relatively high molecular weight and poor solubility in both aqueous and oil phases. Enzymatic hydrolysis represents an effective strategy to improve the techno-functional properties of potato proteins, enabling the development of novel plant-based surfactants [3,4]. In this study, a potato protein isolate was enzymatically hydrolyzed using different proteolytic enzymes (Alcalase® 2.4L FG, Flavourzyme® 1000, Neutrase®, Protamex®, and Papain). The emulsifying properties of the obtained potato protein hydrolysates were evaluated for their potential use as bio-based surfactants. The study first focused on the characterization of the peanut oil/water interface using both static and dynamic interfacial tension measurements, along with interfacial shear rheology analyses. Moreover, the stability of protein-stabilized interfacial films was assessed using the thin film balance technique. Circular dichroism spectroscopy was employed to study the different surface activities of the prepared hydrolysates. Finally, oil-in-water emulsions were prepared, and formulation parameters were optimized by means of chemometric analysis (Figure 1).