Nutritional value and nitrate content in edible wild species used in southern Italy

Thirty-one edible wild herbaceous species were examined to establish the nutritional value with regard to their domestication and the enlargement of their consumption. High levels of nitrate accumulation (> 2,500 mg.kg(-1) f.w.) were recorded in Papaver rhoeas, Eruca vesicaria, Parietaria officinalis, Capsella bursa-pastoris, and Diplotaxis spp. In contrast, in eight other species the nitrate content was < 200 mg.kg(-1). Soluble oxalate were extremely high in Chenopodium album, high in Stellaria media, Portulaca oleracea and Amaranthus retroflexus and wanting species of Sonchus. Mineral content was substantially higher in wild species than in cultivated vegetables. Ca was very abundant in P. officinalis, A. reroflexus and C. album but very low in Asparagus acutifolius, C. album. Amaranthus retroflexus had the highest Mg concentration and Borrago officinalis the lowest. Sea beet, all the Asteraceae species and Malva sylvestris had the highest content of sodium (> 65 mg.100 g(-1)),and the lowest (< 10 mg.100 g(-1)) was found in C. album, Eruca vesicaria, A. retroflexus and P. oleracea. Potassium content ranged between 1,286 mg.100 g(-1) in C. album, and 104 mg.100 g(-1) for Cichorium intybus. The maximum amount of Cl, H2PO4 and SO4 were noted in Asphodeline lutea.