The present invention relates to a method for extracting phenolic compounds with low molecular weights from olive fruit water; the invention also relates to compositions enriched with phenolic compounds including at least 40% of dry matter, said dry matter consisting of at least 30% hydroxytyrosol; the invention also relates to a method for drying said compositions by spraying using grape polyphenol extracts as a drying medium as well as to powders titrated with phenolic compounds of olives and grapes obtained after drying.