Valorization of hydrosol derived from Rosmarinus officinalis cultivated in Metouia oasis

Hydrosols, are by-products of the hydrodistillation of plants. They consist of the distillation water in which very small amounts of essential oils remain dispersed. The aim of this study is the valorization of the hydrosol of a Tunisian aromatic and medicinal plant, Rosmarinus officinalis, by evaluating its phenolic content, antioxidant properties and enzyme activities. Through pH measurements, it has been determined that the hydrolate possesses an acidic character, with pH value falling within the range of 4.9. Total phenolic content assay and antioxidant assays DPPH radical scavenging activity unequivocally demonstrated the presence of antioxidants in the hydrosol and highlighted its potential to combat free radicals. The results showed that Rosmarinus officinalis presented an interested tyrosinase, polyphenol oxidase and lipoxygenase activities. Detected enzymes are identified for the first time in plant hydrosol and are searched for health care and manufacturing industries.