Protein-polyphenol complexes stabilizing emulsions produced in microchannels

Abstract

The production of Pickering particles from vegetable proteins is a strategy that has been commonly used to improve its technological performance as stabilizers of Oil in Water (O/W) emulsions. These particles' performance as a stabilizer can be further improved by complexing the protein with polyphenols, giving the emulsion prolonged kinetic stability and interesting technological properties. Based on these advantages, this project proposes the production of natural complexes formed by lupine protein and proanthocyanidin obtained from grape seed using different formation strategies to verify its stability and potential applications. Despite the abundance of studies involving the synthesis of such complexes, there is still a lack of information about their adsorption kinetics at the oil/water interface, making it difficult to understand the mechanisms involved in stabilizing emulsions, which are related to surface phenomena. Analyzes of dynamic interfacial tension and interfacial rheology, performed in commercial tensiometers, are the standard techniques used for studies related to the anchoring and rearrangement of particles at the interface. However, these measurements are based on the deposition of a single drop of the dispersed phase into a continuous phase, which remains stagnant during the measurement. This model differs from what occurs in conventional emulsion formation processes, in which several drops are produced at flow conditions. In this sense, this work also proposes the use of microfluidic devices to evaluate the adsorption of particles at flow conditions to complement the study of the adsorption kinetics at stagnant condition, and enable the study of the adsorption phenomena in conditions closer to conventional methods. In this context, it is expected that this fundamental study of the adsorption kinetics and the rheological behavior of protein-polyphenol complexes at the oil/water interface provides subsidies to correlate the observed phenomena with the complexes' ability to form and stabilize emulsions produced in microchannels, thus increasing the potential of the complexes for future applications. (AU)