Fructose is the dominant monosaccharide in bilberry juice and red bilberry juice, but glucose is dominant in the cranberry juice. Dominant polyphenols are catechine and chlorogenic acid. In the bilberry and red bilberry juices, the most common acids are citric, quinic and tartaric acids, in the cranberry juice – citric, quinic and malic acids. When bilberry juice is heat-treated for 30 min at 98 C 1 C, HMF content is 2-fold higher than in samples treated at 60 C 1 C. In solutions from lyophilisates of wild berry juice, turbidity and translucent coloration have been determined.