Thomas Bechtold1, Amalid Mahmud-Ali, Rita Mussak. 1. Institute for Textile Chemistry and Textile Physics, Leopold Franzens University of Innsbruck, Hoechsterstraße 73, A-6850 Dornbirn, Austria.
Abstract
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.
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.