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
Morinda tinctoria dyeing of cotton, silk and wool in shades of red, chocolate or purple. The colouring matter is found principally in the root bark and is collected when the plants reach three to four years of age. If the trees are allowed to mature then hardly any colouring substance remains. The small roots yield the most dye and those above about 1 cm diameter are discarded. The active substance is extracted as the glucoside known as morindin that upon hydrolysis produces the dye. Morindone is a mordant dye giving a yellowish-red colour with an aluminium mordant, chocolate with a chromium mordant,