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
Purple mixed light of two longer wavelengths. The resulting color has the same hue as pure violet; however, it has a lower saturation. One psychophysical difference between purple and violet is their appearance with an increase in luminance (apparent brightness). Violet, as it brightens, looks more and more blue. The same effect does not happen with purple. This is the result of what is known as the Bezold–Brücke shift. While the scientific definitions of violet and purple are clear, the cultural definitions are more varied. The color known in antiquity as "Tyrian purple" ranged from crimson to a deep bluish-purple, depending