Optimization of Conventional Extraction for Luteolin Dye from Asphodelus tenuifolius Cav Applied to Wool Fabrics

The purpose of this work was to investigate the performances of natural dyes obtained from Asphodelus tenuifolius Cav aerial parts in wool dyeing. The effect of the extraction process parameters such as extraction bath pH, extraction temperature, extraction duration and weight of plant material and dyeing process parameters including dyeing pH, dyeing duration and dyeing temperature were studied. The best extraction parameters were implemented at a temperature of 40 °C for a duration of 75 min under pH 13 using 8 g of plant material. As for the dyeing process, the ideal conditions were identified as a pH of 3, dyeing temperature set at 100 °C, and a dyeing duration of 45 min. The optimal dye extract was used to dye both mordanted and unmordanted wool garments. It was determined that the addition of mordants affected the color values ; as a result, distinct hues were produced by employing various mordants. Asphodelus tenuifolius Cav aerial parts have good capacity for wool dyeing. Luteolin was isolated, purified and identified by NMR analyses.