Substance mixture comprises (a) polyphenols, flavonoids and/or diterpene glucosides, (b) polysaccharides comprising at least 11 wt.% arabinogalactan proteins, and optionally (c) saponins. An independent claim is also included for preparing the substance mixture, comprising (i) dissolving or dispersing the component (a) in a solvent mixture, which comprises water, triacetin, polyols and alcohols, (ii) mixing the obtained solution or dispersion with an aqueous polysaccharide solution having a content of arabinogalactan proteins present in gum arabic, of at least 11 wt.%, and optionally saponins, (iii) dehydrating the obtained mixture until a residual content of not > 5 wt.%, and optionally (iv) grinding or granulating the dried product to obtain a powder.
