Oliveira, Barbara Miqueletti deColucci, GiovanaSchreiner, Tatiana B.Preegel, GertSilva, Lucimara Lopes daSantamaria-Echart, ArantzazuBarreiro, Filomena2026-03-302026-03-302026Oliveira, Barbara Miqueletti de; Colucci, Giovana; Schreiner, Tatiana B.; Preegel, Gert; Silva, Lucimara Lopes da; Santamaria-Echart, Arantzazu; Barreiro, Maria-Filomena (2026). Lignin–Quercetin Hybrid Colloidal Particles as Sustainable Pickering Emulsifiers: A Bio-Based and Functional Approach. Molecules. ISSN 1420-3049. 31:5, 1-181420-3049http://hdl.handle.net/10198/36379Lignin, the second-most-abundant polymer on Earth, has attracted attention for its value-added applications. Colloidal lignin particles can overcome handling and compatibility issues, offer antioxidant, antimicrobial, and UV-protective properties, and serve as Pickering stabilizers. Plant extracts rich in bioactive compounds, such as polyphenols and flavonoids (e.g., quercetin), can further enhance lignin-based formulations. In this context, colloidal lignin–quercetin particles (CLQPs) were produced for the first time via antisolvent precipitation and used as Pickering emulsion stabilizers. CLQP dispersions (30 g/L) were prepared by solubilizing lignin and quercetin in 80% (v/v) aqueous acetone solution, followed by precipitation with a pH 8 buffer. A quercetin content of 50% (w/w) (CLQP-50) resulted in predominantly round-shaped lignin–quercetin particles (<1 µm) with a small fraction of quercetin crystals. Both structures contributed to emulsion stabilization, as evidenced by confocal microscopy, a three-phase contact angle of 91.6 ± 0.1°, and a zeta potential of −52.8 ± 2.7 mV. CLQP-50 successfully stabilized Pickering emulsions at a 60/40 oil/water ratio, showing high physical stability (stability index 0.01) and shear-thinning behavior with gel-like consistency. These findings demonstrate the pioneering development of lignin–quercetin hybrid colloidal particles as sustainable and functional Pickering stabilizers, opening new opportunities for advanced cosmetic and pharmaceutical formulations.engLigninColloidal lignin particlesQuercetinPickering emulsionsjournal article10.3390/molecules31050889