Extraction of valuable substances (color, polyphenols, flavor)
In case, an extraction of valuable substances is required, it is recommended to work with clear starting material. A fractal column design is recommended. One column acts as a working column which should get loaded to a maximum, the second column is working as a polisher to reduce product losses and increase the yield. Once loaded, the working column will be generally washed with demineralized or softened water to replace non valuable substances and sugars, then eluted with ethanol (generally 40-80% w/w), and subsequently regenerated. The regeneration can be done with NaOH and phosphoric acid at elevated temperatures. In some cases alkaline ethanol is used.
Flavors can be extracted by either eluting them from the adsorbent or strip them with steam if they are volatile enough. The fractal design allows an optimal concentration of the valuable substance in the eluant.