Acorn shell extract as a potential functional finishing agent for textile applications

Abstract Amid growing environmental concerns, agricultural and food industry by-products are increasingly recognized as valuable resources for innovative and sustainable solutions to issues related to ecological preservation and resource-utilization efficiency across various industries. Acorn ( Quercus variabilis ) shells are rich in bioactive compounds such as polyphenols, flavonoids, and tannins, which exhibit well-documented antioxidant and antimicrobial properties. However, they are typically discarded during food processing, and their potential as a source of bioactive compounds remains underexplored. Therefore, the primary aim of this research was to develop a bio-based approach for utilizing acorn shell extract. Bioactive compounds were recovered from acorn shells through aqueous extraction, and the extract was characterized to determine its chemical composition and functional potential. The extract was then applied to cotton fabrics at different concentrations using a pad–dry–cure technique. The treated fabrics were evaluated for colorimetric attributes, surface morphology, chemical interactions, and biofunctional performance, including antimicrobial and antioxidant activities. The results confirmed that the extract was effectively deposited onto the cotton surface, imparting distinct coloration and functional enhancement. Moreover, the intensity of these effects increased with increasing extract concentrations. These findings highlight the potential of acorn shell extract as a bio-based treatment agent for producing more environmentally conscious textile treatments, while also providing a possible means of utilizing an underused agricultural by-product.