The invention provides a method for treating root—or tuber juice, comprising



a) a pretreatment of the root—or tuber juice to remove root—or tuber lipids to a level below 28 g/kg dry weight;
b) cooling the root—or tuber juice to a temperature of −0.3° C. to −16° C. to form ice crystals; and
c) separating the ice crystals from the root—or tuber juice to obtain, as a first root—or tuber juice product, a concentrated root—or tuber juice. In addition, the invention provides methods to obtain protein depleted root—or tuber juice products, as well as products comprising root—or tuber free amino acids, and uses thereof.