Tailoring polyphenol-protein conjugate microgel-stabilized pickering emulsions: a strategic design to decrease the astringency and improve the bioaccessibility and cellular uptake of quercetin

Abstract

The development of complex colloidal systems using food-grade ingredients for emerging applications in food design is a promising strategy to add value to foodstuff. Herein we present the proposal to explore the design of polyphenol-protein conjugate microgels-stabilized Pickering emulsions to reduce the astringency and improve the bioaccessibility and cellular uptake of quercetin (QUE). This proposal is based on a systematic study correlating i) the capacity of protein and its conjugates and conjugate microgels to form stable oil-in-water (O/W) emulsions via conventional and Pickering stabilization; iii) vehiculation of QUE at the interface and in the oil phase; iv) evaluation of the tribological performance - astringent perception; v) evaluation of the gastrointestinal fate of O/W emulsions loaded with QUE in simulated in vitro digestion environment - free fatty acids release, bioaccessibility, cell viability and delivery of QUE to Caco-2 intestinal cells. This project aims to test the following hypotheses: i) the conjugation of polyphenol (QUE) with protein (whey protein isolate - WPI) and the gelation of conjugates and their use as microgels converts the polyphenol quercetin into a non-astringent molecule, and ii) the use of QUE-WPI conjugate microgel as Pickering stabilizers will increase the bioactive compound loading in the carrier system and improve the stability of systems in gastric conditions leading to an enhancement of the bioaccessibility and bioavailability of QUE. The comprehension of the oral and gastrointestinal behavior of systems used in food applications is the key point for developing innovative food systems that meet the demand for customized mouthfeel and nutrition with a common goal of promoting health and well-being for consumers. (AU)