The Development And Application Of The Biological Dye Extracted From The Distiller’s Dried Grains With Solubles

Xanthophylls are yellow pigments found in highest quantity in the leaves of mostgreen plants, and also in the flowers or fruits of plants such as maize, marigold,spinach, etc. They are form one of the most abundant colorants found in nature nextonly to chlorophylls. Xanthophylls and closely related carotene pigments are widelyused as colorants and additives in food industry due to their brilliant color and abilityto quench radicals. However, the application of xanthophylls and textile dyes werescarce. The current work propose to use xanthophylls extracted from Distiller’s DriedGrains with Solubles (DDGS) and bought in the form of marigold extracts to dyewool fabrics. Thanks to the fast expanding bio-ethanol industry, large volume ofDDGS are produced each year globally, which makes it an ideal natural resources forxanthophylls. Marigold extract has been the most common form of xanthophyllsfound on market.Three different DDGS from China and the U.S. were subjected to ethanolextraction. Results showed the extractable xanthophyll contents were0μg/g,38μg/g, and128μg/g respectively. Stability of the extracted pigments were investigatedunder various pHs. Significant discoloration or xanthophyll degradation was observedunder pH values less than3. The results indicated that dyeing should be performedunder nutral or slightly basic conditions to avoid undesirable pigment decomposition.In the dyeing experiments, dyeing properties of xanthophyll dyes wererepresented as color depth or K/S values of the dyed wool fabrics. The effectssurfactants, co-dyeing solvents (for better dye dispersion), antioxidant as dyeing auxiliaries, dyeing temperature, and dyeing time were investigated. The resultsshowed that highest K/S could be achieved with a mixture of4:6diglyme and water at80°C. The most significant improvement in dye up-take was achieved with2,6-di-tert-butylphenol as dyeing auxiliary. The optimum dosage was found to be9:1auxiliary to dye, in which case the K/S value of wool fabric dyed with1%o.w.fmarigold extracts increased from4.20to10.49. The colorfastness of the dyed woolfabric was acceptable and could be further improved by treating with softeners orfixation agents. Polyethylene softener ADALIN NI was found to be the most effectiveaddictive.The dyeing rate curve and the sorption isotherm was measured at differentdyeing conditions. The dyeing rate curve shows that adding2,6-di-tert-butyl-phenolsignificantly enhanced both the rate of dyeing and the equilibrated concentration ofdye on fabric. Under all conditions studied, the sorption isotherms of xanthophylldyes for wool fabric dyeing fit with the Langmuir Sorption Isotherm. Judging fromthe1HNMR spectrum of the mixture of2,6-di-t-butylphenol and the dye, the twospecies form a hydrogen bonded complex, which is less soluble and possesses higheraffinity for the wool.In conclusion, xanthophyll dyes were shown to be applicable to dye wool fabricin light to medium dark shades.(K/S value up to13.52). The colorfastness of the dyedfabric were moderate to good and can be further improved by aftertreatment to meetthe practical demands. The results have implications for the application ofxanthophyll and related natural colorants in textile dyeing.