Dyeing and Functionalizing Mulberry Silk With Phenolic‐Amine Conjugates of Catechin and Gallic Acid

A laccase‐catalyzed coloration process was explored as a sustainable alternative to traditional dyeing methods. Laccases play a key role in textile processing owing to their remarkable versatility and broad substrate specificity. This study deals with the simultaneous dyeing and finishing of mulberry silk fabrics with the laccase‐catalyzed phenolic conjugates of catechin and gallic acid with the amino acid (glycine). The results demonstrated that the colored silk showed maximum color depth at pH 5 (K/S = 18.663 and 16.609) and temperature at 50°C (K/S = 17.411 and 13.401) for catechin and gallic acid conjugates, respectively. Silk fabric was pre‐treated with beta‐cyclodextrin (β‐CD) and guar gum before dyeing with the conjugated products as an alternative to metallic mordants. The results of colorfastness demonstrated that dyed silk exhibited strong dye stability (rating 4‐5) in terms of washing and rubbing fastness. Functional properties of the dyed fabrics, such as antioxidant, UV protection, and antibacterial properties, were evaluated. The results showed higher antioxidant activity, satisfactory antibacterial property, and good UV protection capabilities. UV–vis spectral and FTIR analysis of the laccase‐catalyzed conjugated products (LCCPs) was done to confirm the conjugation reaction. Thus, an innovative approach of enzyme‐catalyzed coloration on silk fabrics was investigated.