Extraction of Anthocyanin Pigments from Red Onion (Alliumcepa L.) and Dyeing Woolen Fabrics


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Özgür M. , Gümrükçü Köse G.

Asian Journal Of Chemistry, cilt.4, ss.2891-2902, 2008 (SCI Expanded İndekslerine Giren Dergi)

  • Cilt numarası: 4 Konu: 20
  • Basım Tarihi: 2008
  • Dergi Adı: Asian Journal Of Chemistry
  • Sayfa Sayısı: ss.2891-2902

Özet

Natural colours have attracted the attention of the entire

world because of their non-hazardous nature. In present study,

woolen fabrics were dyed with natural dyes derived from redonion

(Alliumcepa L.) using various mordants by open bath

dyeing technique. Natural dye (anthocyanins) was extracted

from red-onion skins with acetic acid:ethanol:water (1:80:19,

v/v/v) mixture solution. The amount of total anthocyanins

was determined by using the derivative spectrophotometric

method and found to be 13.5 mg/100 g for fresh onion skin

and 5.2 g/100 g for dry onion skin. Dyeing processes were

carried out according to pre-, together- and last-mordanting

methods by using buffer solutions at the pH = 2-8 interval

and for 1 h at 98-100 ºC. Some metal salts such as Al(OH)3,

Cu(NO3)2, Fe(NO3)2, Zn(NO3)2, NiCl2, SnCl2, Pb(CH3COOH)2

were used as mordantation agents. In addition, various studies

were carried out on the effect of mordant quantity and kind

of mordant salt in dyeing. The colour changes were evaluated

instrumentally with a colour difference meter. Colour differences

in CIE L*a*b* units and gray scale classifications were

reported. Dyeing conditions and other characteristics showed

that mordant was more important than dye in predicting

lightfastness of coloured textiles and good lightfastness which

was between 2 and 4 values were obtained.