espèce (2) Afrique (2) Species (2) South Africa (2) Sources (2) Sources (2) élément trace (1) norme (1) sol (1) recherche (1) nutrition (1) minéral (1) ménage (1) aliment (1) air (1) investigation (1) dommage (1) Afrique (1) comparaison (1) calcium (1) Nutrition (1) Context (1) Food (1) Comparison (1) Varieties (1) Identification (1) Phytochemicals (1) Minerals (1) Vegetables (1) Values (1)