Sustainable Extraction of Colourant from Harmal Seeds (Peganum harmala) for Dyeing of Bio-Mordanted Wool Fabric

Abstract

The recent pandemic scenario has caused demand for green products that have medicinal aspects, as well as greener approaches for global health. Natural dye from plants, particularly from harmal seeds, is an excellent alternative to carcinogenic yellow synthetic dyes. The current study has been conducted to isolate natural colorants from harmal seeds in methanolic medium through Gamma-Assisted Extraction (GAE). The dyeing variables that are necessary for shade development before and after mordanting were selected. It has been found that 6 kGy is the optimal absorbed dose for extraction of colorant from 6 g of powder to isolate the colorant in the methanolic medium through the Gamma-irradiated extraction mode (GAE). To get excellent results, 30 mL of methanolic extract containing 6 g/100 mL of Glauber salt was sued for dyeing of irradiated wool at 45 °C for 65 min. For improving the color strength and acceptable rating of fastness, 9% of henna, 3% of acacia, 10% of turmeric, and 7% of pomegranate extracts as pre-bio-mordants as well as 7% of acacia, 3% of pomegranate, 9% of henna, and 10% of turmeric extracts as post-mordants have given high results compared to when chemical mordants have been used. It was concluded that Gamma-ray treatment has excellent color strength in the dyeing of bio-mordanted wool using harmal seed extracts under mild conditions, and has good fastness ratings after using chemical and bio-mordanting methods as well.