GCMS profiling and dyeing properties of natural dye from Western Himalayan walnut ( Juglans regia L.) green husk: Focusing on textile applications

Abstract

This study investigates the natural dyeing potential and comprehensive GCMS profiling of green husk of wild‐growing western Himalayan walnut ( Juglans regia L.) for textile applications. The phytochemical analysis revealed high phenolic content (181.7 ± 1.5 mg GAE/g) and flavonoid content (77.4 ± 2.1 mg CE/g) along with carbohydrates (62.4 ± 1.8 mg/g), moisture (5.2 ± 1.0%) and ash content (18.4 ± 1.8%). FTIR analysis indicated the presence of phenolic O‐H stretches, carbonyl groups and aromatic C‐H bonds. GCMS profiling identified several phytochemical constituents contributing to dye performance. The dye extract exhibited antioxidant activity (85.4%) with an IC ₅₀ value of 20 μg/mL. Cotton fabric dyed with and without mordant (alum, iron sulphate) demonstrates good to excellent fastness grades (4, 5), colour strength ranging from 3.8 to 4.2 with highest depth obtained using iron sulphate compared to un‐mordanted fabric, lightness (L) ranging from 60.6 to 74.9, hue shifts (h°) around 80–82° depending on mordant type. The dyed fabric also showed excellent ultraviolet protection (UPF 50 ⁺ ). These results indicate the potential of green husk of wild‐growing western Himalayan walnut as a sustainable and less environmentally harmful dye alternative for the industrial sector.