Mineral composition and ascorbic acid content in four non-conventional leafy vegetables species

Non-conventional vegetables show higher nutrient levels than the conventional ones, but their potential for production and consumption has been neglected and there have been few studies about their chemical composition. This study has investigated the levels of ascorbic acid (vitamin C) and minerals in the following non-conventional leafy vegetables: taro, ora-pro-nobis, bertalha and purslane. The taro leaves showed the highest levels of ascorbic acid (198.33 mg 100 g(-1) fresh weight) and nitrogen (5.02 g 100 g(-1)), boron (0.0032 g 100 g(-1)), manganese (0.0069 g 100 g(-1)), in dry matter (DM). The leaves of ora-pro-nobis showed similar levels of ascorbic acid and the highest levels of phosphorus (0.45 g 100 g(-1)DM) and magnesium (0.68 g 100 g(-1)DM). In purslane leaves there were the highest iron (0.0324 g 100 g(-1)DM) and calcium (2.39 g 100 g(-1)DM) content. Concerning to zinc levels, the species that stood out were bertalha (0.0057 g 100 g(-1)DM) and ora-pro-nobis (0.0059 g 100 g(-1)DM). As for potassium, there was no significant difference amongst species (3.71 to 3.87 g 100 g(-1)DM). These species may become good sources of ascorbic acid and minerals with the spread of their use by the population.