Dyeability, UV-protection and antimicrobial activity of cotton and silk fabrics dyed sequentially with fermented pepper seeds and medicinal plants

Purpose The study aims to develop a zero-waste, sequential dyeing method using fermented pepper seed extract followed by Saururus chinensis (SC) and Chrysanthemum zawadskii (CZ) to achieve a vibrant color and added functionality for silk and cotton. Design/methodology/approach Silk and cotton fabrics were mordanted, then dyed with fermented pepper seed extract before undergoing sequential dyeing with SC followed by CZ. Color performance was evaluated by measuring the change in CIELAB and Kubelka–Munk values. Fastness to washing, light and rubbing was tested according to ISO standards. Air permeability was determined under 100 Pa pressure, UVB blocking was assessed via spectrophotometry and antibacterial efficacy was quantified against Staphylococcus aureus (S. aureus) and Klebsiella pneumonia (K. pneumoniae) using a shake-flask method. Findings Silk dyed with fermented pepper seed extract demonstrated excellent color quality and fastness properties, with post-mordanting using chestnut shell extract showing better lightfastness (grade 4–5) than pine bark extract (grade 2). Cotton fabrics dyed with the fermented pepper seed extract, followed by sequential dyeing with SC and CZ, developed soft pastel hues, with rubbing fastness grades 4–5 and light fastness grades 2–3. Both SC and CZ exhibited significant antibacterial activity, with over 99% effectiveness against S. aureus, and CZ also showed strong antimicrobial effects against K. pneumoniae. Mordanting decreased the air permeability of the fabrics but increased UVB protection, with rates of 89.8% for pine bark and 95.6% for chestnut shells. Originality/value Applying fermented pepper seed extract in an initial dye bath, followed by successive SC and CZ treatments, produces vivid natural coloration along with strong antibacterial and UV-protective properties – demonstrating a sustainable, zero-waste route to multifunctional textile finishing.