Asperyellone – a suitable coloring agent for protein based textile fabrics: an approach on production, characterization and application

Abstract

Color is the first thing which is perceived by the senses. Natural colorants are extremely safe because of its added advantages. The present study describes extraction, characterization and application of a yellow pigment from Aspergillus species, strains AN01 and explores its wider applications. The chosen strain isolated from the soil displayed an extracellular yellow pigment production when grown at specific nutrient and growth conditions. The yellow color pigmented solution free from spores extracted, concentrated, purified and subjected to characterization using UV, FT-IR, DSC, TGA, GC-MS and NMR analyses. From the results the yellow pigment is identified as Asperyellone. Coloring efficacy of the yellow pigment on silk, cotton, synthetic and wool fabrics demonstrates appreciable color uptake by the materials. Increased dye uptake is observed in the protein fibers and polypropylene. The high K/S values corroborate substantiates the preference of Asperyellone pigment to proteins than other natural or synthetic fabrics. The fastness of the pigment on the various substrates is found to be good except to the light fastness. Additional molecular docking studies with silk protein and Asperyellone display the interaction and appreciable binding energy. The above results authenticate the suitability of yellow pigment to enhance the organoleptic property of silk, which ultimately will improve the export value at appreciable level.