This research work involves the dyeing of wool with indicaxanthin, a natural dye extracted from fruits of
Opuntia ficus-indica. The optimal conditions for dye extraction were to mix 50 g of Juice from cactus pears
with 100 mL of 80% aqueous ethanol as solvent for dye extraction. Liquid chromatography was applied
for the separation. Two main dyes were obtained, which were identified as indicaxanthin (75 mg per 50 g)
and betanin (5 mg per 50 g). The effect of dye bath pH, salt concentration, dyeing time and temperature
were studied. The optimal conditions for wool dyeing with indicaxanthin dye were carried out at 70 ◦C for
90 min with the pre-treatment of various metal salts as mordant. The colour yields of the dye on the wool
were found to be highly dependent of the pH, optimum results being obtained at pH 4. The K/S of wool
increased in the order of the dyeing using KAl (SO4)2 > MnSO4 > CoSO4 > FeSO4 > none > ZnSO4 > CuSO4.
Un-mordanted samples have good properties of water and washing fastness. Mordants KAl (SO4)2 and
CoSO4 were found to give good light fastness (rating 5).