Roman Chamomile Seed Extraction and Analysis

Roman chamomile (Chamaemelum nobile, Asteraceae) seeds, produced in the year 2021, were purchased from HerbFarm Edwin Lewczuk (Poland). CO₂ (purity 99.9%) produced by Grupa Azoty (Zaklady Azotowe “Pulawy” S.A., Poland) was used for SFE. Trimethylsulfonium hydroxide solution (TMSH ∼0.25 M in methanol, Sigma-Aldrich, USA) and methyl tert-butyl ether (MTBE, Avantor Performance Materials LLC, USA) were used for converting fatty acids into methyl esters. Folin and Ciocalteu (2 M with respect to acid), gallic acid (97.5–102.5%), quercetin (≥ 95%), and aluminum chloride (99.99%) purchased from Sigma-Aldrich (Germany) as well as isopropanol (min 99.8%, ChemSolute®, Germany) and sodium carbonate (99.8%, Poch, Poland) were used for the evaluation of phenolic and flavonoid content. 2,2-Diphenyl-1-picryl-hydrazyl (DPPH) and L-ascorbic acid (reagent grade) were obtained from Sigma-Aldrich (Germany) and used for evaluation of antioxidant activity.