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Anthocyanin dyes extracted from grape pomace for the purpose of textile dyeing.

BACKGROUND
Pomace from different grape varieties was studied with regard to the content of extractable anthocyanins.


RESULTS
Total anthocyanin concentrations of 24.5-126 mg dm(-3) were found in the extracts. The amount of extractable pigment was dependent on the variety of grape. The extracts were applied in textile dyeing operations using cotton fabric pre-mordanted with tannin as textile substrate. Red/violet shades were obtained that showed good water-fastness; however, limited light-fastness indicated need for improvement to fulfil requirements for textile application.


CONCLUSION
Colour measurement by means of CIE-Lab coordinates and Kubelka-Munk value showed a direct correlation between extractable anthocyanin concentration and colour depth of the dyed material. Thus the analytically determined concentration of anthocyanins in the aqueous extract can serve as a measure of quality of grape pomace as raw material for textile dyeing application. Copyright © 2007 Society of Chemical Industry.