Eco-friendly Extraction of Flavonoids Dyes from Moroccan (Reseda luteola L.), Wool Dyeing, and Antibacterial Effectiveness

Greater importance should be attributed to finding environmentally friendly processes that are particularly suitable for the textile industry. In this work, we exploit the plant (Reseda luteola L.) for the extract of a natural yellow dye, using the tannic bark of Acacia mearnsii as a bio-mordant to ensure sustainable dyeing of wool fabrics. Four important extract parameters were optimized: hydroethanolic extract, pH = 7, 80 degrees C temperature, and a short duration of nearly 30 min as time of extraction. The pigment's chromatographic profile shows that 7-O-glucoside luteolin is the most dominant flavonoid in the extract. The extract shows good thermal stability up to 90 degrees C and pH stability under acid and neutral conditions. Then, the dyeing conditions were optimized in terms of color strength (K/S) values to produce textile shades with acceptable colorimetric characteristics of (K/S = 23.2). Pre-mordanting with alternative bio-mordant (alum stone and Acacia mearnsii tannin) improved the overall absorption of dyes into the fabric, producing a range of colors from pale yellow to dark brown, and showing strong resistance to washing and wet and dry rubbing. In addition to its good dyeing property, the fiber dyed with 100% of the extract shows antibacterial effect against Gram-positive Staphylococcus aureus bacteria, so it can be used in future applications to produce antimicrobial textiles.