The “manna” extracted from the ash trees still cultivated in Sicily from mythical food to pharmaceutical and nutraceutical resource

Abstract

“Manna” is the product obtained from the solidification of the elaborate sap that comes out of the incisions made during the summer season on the stem and on the main branches of some species of the genus Fraxinus (Oleaceae). The cultivation of manna ash trees dates back to ancient times in Sicily and elsewhere ash trees – known as sacred trees, a symbol of abundance and therefore auspicious – was increasingly widespread until the middle of the last century. Subsequently, however, the crop underwent a progressive decline, remaining relegated to restricted areas of Sicily, in particular in the Madonie district (Palermo, Italy). In this brief review, the essential characteristics of the manna and the ash trees from which it is extracted are summarized. The aspects of the current productivity of manna in the Sicilian territory and the implications of a potential recovery and increase of an ancient craft, ash tree cultivation, are also reported in a perspective of sustainable development and green economy for the Mediterranean area and beyond. Finally, the authors remember what has been done to ensure the conservation not only of the active cultivation of manna ash but also of all the relative agro-biodiversity. The conservation of the living germplasm of the ancient cultivars recovered in the Madonie area (Palermo, Sicily) represents one of the most qualifying results.