This study aimed to assess the behaviour of phenolic compounds from yarrow extract encapsulated in nanoemulsions during in vitro gastrointestinal digestion. Oil-in-water nanoemulsions were developed using grape seed oil and lupin protein (LPI) as oil phase and emulsifier, respectively. The use of 6 % LPI including 1 mg/mL of yarrow extract resulted in nanoemulsions with a homogeneous particle size distribution (200 nm) and an encapsulation efficiency of 85.6 %. During in vitro gastrointestinal digestion, most of the phenolics remained encapsulated, being protected from degradation. The in vitro bioavailability of the encapsulated phenolics was measured using a cell co-culture model (Caco-2/HT-29MTX). In this regard, nanoemulsions did not increase the bioavailability of yarrow phenolics, instead, they promoted their access to the colon. Finally, the antiproliferative activity was determined in Caco-2 cells, observing that the apical fraction inhibited cancer cells, indicating the bioefficacy of the non-absorbed phenolics. Thus, this study underscores the potential of LPI-stabilized nanoemulsions as a vehicle for protecting and delivering yarrow phenolics to the colon.

This work was supported by the Spanish Government (Project: PID2019\u2013110183RB-C22/MCIN/AEI/10.13039/501100011033) and by the Villum foundation through the Villum investigator award. M.N. Siles-S\u00E1nchez thanks Universidad Aut\u00F3noma de Madrid for the grant \u201CFormaci\u00F3n de Personal Investigador (FPI) UAM 2019\u2033. The authors declare that the research conducted in this study has not involved studies in humans and animals.