Evaluation of various techniques for extraction of natural colorants from pomegranate rind-Ultrasound and enzyme assisted extraction

摘要

Ultrasound, enzyme and enzyme-mediated ultrasound assisted extraction processes have been used for the extraction of dye from pomegranate rind. Optimum parameters for dye extraction are found to be pH 10, extraction time 40 min and temperature 50 °C. The yields for ultrasound, enzyme, enzyme-mediated ultrasound assisted and solvent extraction are found to be 29.2%, 26.5%, 35.6% and 8.8% respectively. The dye obtained has been used for dyeing wool and cotton, keeping the optimum dye bath concentration as 10% and 8% (w/v) respectively. The fastness properties of wool are found to be very good while that of cotton is only satisfactory.