Carrageenan is that the carrageenan is first dissolved and filtered to remove cell wall debris. The carrageenan is then precipitated from the clear solution either by isopropanol or by potassium chloride. A hybrid technology in which seaweed is treated heterogeneously as in the semirefined process exists, but alcohol or high salt levels are used to inhibit dissolution. This process is often used on South American seaweeds and gives some of the cost benefits of semirefined processing, while allowing a wider range of seaweeds to be processed, however, the naturally low cellulose levels in some South American seaweeds allow them to be
Ethnolichenology from lichens were historically very important throughout Europe from the 15th to 17th centuries. They were generally extracted from "Roccella" spp. lichens imported from the Canary Islands, Cape Verde Islands, Madagascar, or India. These lichens, and the dye extracted from them, are called orchil (variants archil, orchilla). The same dye was also produced from "Ochrolechia" spp. lichens in Britain and was called cudbear. Both "Roccella" spp. and "Ochrolechia" spp. contain the lichen substance orcin, which converts into the purple dye orcein in the ammonia fermentation process. Litmus, a water-soluble pH indicator dye mixture, is extracted from "Roccella" species. Many lichens