Evaluation of antioxidant, antibacterial and fastness properties of erythrina abyssinica extracts on cotton fabric using biomordants

Abstract

Due to the toxicity of synthetic dyes, natural dyes have been touted as possible alternatives owing to their ecofriendliness and ability to impart bio-functional properties, such as antibacterial, antifungal and antioxidant properties, especially when natural dyes are mordanted using with biomordants. The aim of the study was to evaluate the effects of using biomordants on the natural dyeing properties of Erythrina abyssinica dye extract, and to evaluate their antioxidant and antimicrobial biofunctionalization properties on cotton fabric. The biomordants used in this study were from mango bark and rosemary extracts. The antioxidant activity of the dyed cotton fabric was established using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) method, while the antimicrobial activity of cotton fabric was measured against the Escherichia coli and Staphylococcus aureus strains of bacteria using the direct absorbance method. The use of biomordants in dyeing led to an increase in colour strengths from 0.601 to 0.762 and 0.692 for rosemary and mango biomordants, respectively. Cotton dyed using E. abyssinica demonstrated an antioxidant activity of up to 78.6 1%. The dye imparted a microbial reduction ability of up to 69.11% and 70.06% against E. coli and S. aureus, respectively, to the fabric. Dyeing properties, such as wash fastness, light fastness, colour fastness and perspiration, improved after biomordanting. It can thus be concluded that E. abyssinica dye extracts are suitable for textile dyeing and biofunctionalization