Stoyanova, YoanaYoanaStoyanovaLazarova-Zdravkova, NevenaNevenaLazarova-ZdravkovaPietsch-Braune, SwantjeSwantjePietsch-BraunePetrin, StoykoStoykoPetrinStefanova, AnnaAnnaStefanovaHeinrich, StefanStefanHeinrichPeshev, DimitarDimitarPeshev2026-03-032026-03-032026-02-23Membranes 16 (2): 76 (2026)https://hdl.handle.net/11420/61757The present study explores the possibility of combining membrane concentration, spray drying, and low-temperature precipitation into a single process for the valorization of spent lavender biomass as a source of ingredients rich in antioxidants. Lavender spent plant material was subjected to solid–liquid extraction, and the obtained hydroalcoholic extracts were further concentrated using a dead-end membrane filtration cell (METcell) with a polyamide–urea thin-film composite X201 membrane. The feed and the obtained retentate were subsequently spray dried using a Nano Spray Dryer B-90 (BÜCHI) under different temperature conditions (120 °C and 85 °C). Low-temperature precipitation was further applied for the retentate. An eight-fold concentration of the extracts was achieved, with membrane rejection coefficients of 100% for antioxidant activity and 98.5% for dry solids content. The permeate flux ranged from 2.25 to 0.201 L·m^−2·h^−1. Spray drying at a lower inlet temperature resulted in minimal losses for antioxidant activity (below 6%). The low-temperature storage of the membrane concentrate led to clear phase separation, allowing for the recovery of a precipitated fraction. The obtained results demonstrate that the integrated approach may support the sustainable and scalable valorization of lavender by-products.en2077-03752026Multidisciplinary Digital Publishing Institutehttps://creativecommons.org/licenses/by/4.0/Technology::660: Chemistry; Chemical EngineeringTechnology::660: Chemistry; Chemical Engineering::660.6: BiotechnologyJournal Article2026-02-26https://doi.org/10.15480/882.16791doi: 10.3390/membranes1602007610.15480/882.16791Journal Article