Nutritional and toxic factors in selected wild edible plants.
Nutritional (ascorbic acid, dehydroascorbic acid and carotenes), antinutritional and toxic components (oxalic acid, nitrate and erucic acid) were determined in 16 popular species of wild edible plants which were collected for human consumption in southeast Spain from March to June 1992. Ascorbic and dehydroascorbic acids contents were very high in several species, especially in Chenopodium album (155 mg/100 g). Carotenoid content ranged from 4.2 (Stellaria media) to 15.4 mg/100 g (Amaranthus viridis). A range of values was found for oxalic acid from absence to 1100 mg/100 g of plant material. Nitrate contents ranged from 47 (Salicornia europaea) to 597 mg/100 g (A. viridis). Low amounts of erucic acid were found in the Cruciferae [Brassicaceae] family (Sisymbrium irio 1.73%; Cardaria draba 1.23%) and Plantago major 3.45%. It is concluded that these plants are a good source of ascorbic acid and carotenes, but due to the amounts of oxalic acid and nitrate they contain, a high consumption is not recommended, especially of A. viridis, Chenopodium and Portulaca oleracea.