**3.2. Qualitative screening of tannins and phlobatannins**

Most of the tannins, a group of phenol compounds usually found in plants, are soluble in water. Phlobatannins are considered a novel class of ring-isomerized condensed tannins [17].

The test for tannins is generally described as [27]: to 1 ml aqueous extract 2 ml of 5% ferric chloride are added and a dark-blue or greenish-black color appears.

Phlobatannins are tested following a standardized method: to 1 ml aqueous extract of sea buckthorn and gooseberry few drops of diluted HCl (1%) is added and a red precipitate should appear (**Table 5**).

Tannins are present in both aqueous extracts, while small traces of phlobatannins can be found in gooseberry aqueous extract.
