Characterizing dyeing constituents from walnut green husks: Utilization of a harmful agricultural by-product as natural dye to alleviate its environmental pollution

作者：Sandra Amarachi Ozuzu, Gift Donu Fidelis, Zokir Toshmatov, Nigora Kuchkarova, Bernard Edache Ochekwu, Hua Shao · 发表于：Industrial Crops and Products · 年份：2024 · DOI：10.1016/j.indcrop.2024.120172 · 被引用次数：6 · 研究领域：Dyeing and Modifying Textile Fibers、Dye analysis and toxicity、Pigment Synthesis and Properties

Walnut green husks (WGHs), a by-product of walnut cultivation, poses significant environmental concerns due to their indiscriminate disposal practices. To alleviate this problem, this study explored the possibility of utilizing WGHs as a resource of natural dyes focusing on the characterization of responsible bioactive compounds. The crude aqueous extract of WGHs displayed excellent dyeing activity on fabrics, resulting in a brownish color; further chromatographic fractionation revealed that the distilled water (dH 2 O) fraction of the extract yielded from macroporous resin column chromatography exhibited the best dyeing effect compared with other ethanol-based fractions (20 %, 60 %, and 90 %). Based on the subsequent LC-MS/MS, FTIR, and UV-Vis analysis, six most dominant, colored compounds that are commercially available were chosen for evaluating their dyeing capacity, including β-carotene, 2,4-dinitrophenol, phylloquinone, astaxanthin, quercetin 3-sambubioside and avicularin, and indeed their mixture displayed similar dyeing effect as the dH 2 O fraction and the crude extract of WGHs on fabrics. The isolated compounds and their mixture exhibited comparable dyeing performance to the crude extract, with notable K/S color strength values. Colorimetric analysis revealed distinct CIEL*a*b* values for each compound; furthermore, the dyed fabrics demonstrated moderate-excellent colorfastness. Our study implied that WGHs extract and ingredients have the potential to be utilized as...