Ultrasound-assisted extraction of natural dyes from Hawthorn fruits for dyeing polyamide fabric and study its fastness, antimicrobial, and antioxidant properties

Due to increasing awareness about the environmental impacts of oil-based synthetic dyes used in textile coloration, the research on natural dyes from sustainable resources has gained importance again. In this study, the ultrasound-assisted extraction (UAE) technique was employed for the extraction process of colorants from Hawthorn fruits. Various solvents (e.g., methanol, acetone, ethanol, water, a mixture of ethanol and water) were used for the extraction process. Compared to the conventional extraction technique, the UAE technique was found to improve the extraction efficiency between 20 and 70% depending on the type of solvent. The synergistic dye extraction efficiency was observed when a mixture of water and ethanol was used for conventional and UAE processes, and consequently, W1/4E was selected as the most efficient mixture. The important parameters, such as dried fruit powder concentration, initial pH, extraction time and temperature, were optimized using the response surface methodology (RSM). A second-order polynomial model was developed for estimating the extraction efficiency based on the important initial parameters. The maximum extraction yield was achieved at the initial dried fruit powder of 8 g/L, at pH 5, 60 °C after 40 min. Three main flavonoids (i.e., quercetin, rutin, kaempferol) were detected in the extracted solvent from Hawthorn fruits by FTIR and HPLC techniques. Polyamide (nylon 6) fabric was successfully dyed by the extracted natural colorants with relatively high colorfastness properties. The dyed fabric also showed remarkable antimicrobial properties against E. coli and S. aureus. This study indicated that the natural colorants extracted from Hawthorn fruits were promising for textile coloration with noticeable antioxidant and antimicrobial properties.