Overview
The present invention relates to a novel method for extraction of dark herbal colours utilizing cold as well as hot extraction of different plant parts using environment friendly solvents. The blue colour is extracted from leaves of Piper retrofractum and Solanum nigrum flowers; red colour is extracted from seeds of Stevia rebaudiana and also from the bark of P. santalinus and yellow colour is obtained from rhizomes of Curcuma longa. The yellow and blue colours are extracted using glacial acetic acid whereas the red colour is obtained from seeds of Stevia rebaudiana using IPA and bark of P. santalinus using methanol.