Prepn. of technically pure indigo from fresh plant material - by opening up cells, dissolving indigo precursors, removing plant components, fermenting to give indigotin and sepg. indigotin

摘要

In prepn. of technically pure indigo from plant material, (a) the material is recovered directly from fresh plant material, (b) the plant cells are opened up mechanically or with steam, (c) water-sol. indigo precursors in the substrate are dissolved by heating, boiling or treatment with steam, opt. under excess pressure, (d) suspended and/or colloidal plant components are removed before fermentation, (e) the substrate is fermented, then indigotin is formed from the precursors, (f) the suspended and/or colloidal indigotin is sepd. from the fermentation prod., and (g) the sepn. processes for the purification and sepn. of the indigotin are adjusted so that the fermenting substrate contains no plant components which are sepd. with the indigotin. USE/ADVANTAGE - Indigo is used in dyeing, esp. of textiles. Indigo of technical quality can be obtd. on the large scale by an environment-friendly process. Direct dyeing in the fermentation bath reduces the waste problem. Waste material can safely be used on the land. Energy is needed only for the first extn., and any waste heat from the engine can be used in the harvester. Undried green material is used, needing no, or only a little, process water