<p>Bixin, a carotenoid compound extracted from annatto seeds, is recognized for its antioxidant properties and is commonly utilized as a food colorant. Here, bioactive compounds were extracted from annatto seeds using an aqueous ethanolic mixture as solvent, and the extract was sequentially filtered through asymmetric alumina hollow fiber membranes. The annatto seed extract presented a total phenolic content of 3.12 ± 0.01&#xa0;mg_GAE/g of seeds and a bixin concentration of 1.262 ± 0.142&#xa0;mg&#xa0;g⁻¹. The microfiltration process through the ceramic hollow fiber membrane was efficient in concentrating the bixin molecules, with retention factors of 54.2 ± 0.8% for total phenolic compounds and greater than 90% for bixin molecules. The antioxidant activity of the permeate was statically equivalent to the feed extract. Thus, the membrane was efficient in retaining the long-chained bixin molecules and some of the phenolic compounds, while most of the antioxidant compounds were permeated through the membrane.</p> Graphical abstract <p></p>