Style decolorization treatment of denim fabric: Decomposition of indigo dyes via horseradish peroxidase/H2O2 system at room temperature

The decolorization treatment for denim fabric (jeans) could give the fabric a bright blue and white appearance, a sense of vintage, and meet the needs of different styles. In industrial production, the common decolorization methods included sphysical methods such as stone grinding and water washing, which can cause strong damage to the fabric, and chemical methods such as bleach washing and snow washing, which also have some problems of environmental pollution. Therefore, an efficient, clean, and controlled decolorization method for denim fabric was proposed using the horseradish peroxidase/H2O2 system, which was first reported in this article. The optimized decolorization treatment process was studied, and the optimal process was as follows: the dosage amount of horseradish peroxidase was 150 u/mL, the dosage amount of H2O2 was 2.5 mL/L and added 3 times, the pH of buffer solution was 5, the reaction temperature and time were 35 °C for 1 h. And controllable (local) decolorization of denim fabric was applied through printing methods. The decomposition mechanism and reaction kinetics of indigo by the horseradish peroxidase/H2O2 system was also analyzed and proved the indigo was decomposed into the isatin and some small molecule substances. In addition, compared with cellulase and laccase decolorization methods, the horseradish peroxidase/H2O2 system has the advantages of no anti-staining, high efficiency, and environmental protection. It was expected to become a promising partial style decolorization treatment method.