Carrageenan each plant weighs approximately 1 kg. The "E. cottonii" variety has been reclassified as "Kappaphycus cottonii" by Maxwell Doty (1988), thereby introducing the genus "Kappaphycus", on the basis of the phycocolloids produced (namely kappa carrageenan). After harvest, the seaweed is dried, baled, and sent to the carrageenan manufacturer. There the seaweed is ground, sifted to remove impurities such as sand, and washed thoroughly. After treatment with hot alkali solution (e.g., 5–8% potassium hydroxide), the cellulose is removed from the carrageenan by centrifugation and filtration. The resulting carrageenan solution is then concentrated by evaporation. It is dried and ground to specification.
Han purple and Han blue not a pigment). The purple color seen in samples of Han purple is created by the presence of red copper (I) oxide (CuO) which is formed when Han purple decomposes (the red and blue making purple). The decomposition of Han purple to form copper (I) oxide is Above 1050 °C, the CuO copper (II) oxide breaks down to copper (I) oxide: Both Han purple and Han blue are barium copper silicates (containing barium, copper, silicon, and oxygen). However, they differ in their formula, structure, and chemical properties. Han purple has the chemical formula BaCuSiO. Han purple has a layered structure