Nutritional profile of the Portuguese cabbage (Brassica oleracea L var. costata) and its relationship with the elemental soil analysis

The economic and financial crisis has increased the number of urban horticulture on lands close to present or past industrial areas. "Tronchuda" or the Portuguese cabbage (Brassica oleraceae L var. costata DC) was studied because of its importance in Portuguese diet. It belongs to a number of economically significant horticultural crops (Brassica species), which are also known to be nutritionally well-balanced vegetables. "Tronchuda" produced in urban horticultures from 4 regions of mainland Portugal was studied for its nutritional profile along with elemental soil analysis of each sampling site. This study revealed significant interactions between essential elements in soil and plant leaves - the edible part of the plant for human nutrition. In general, these organs contained poor concentrations of Fe and Si, while Mn is absent, regardless of the sampling sites. Conversely, Ca levels were abundant with values ranging between 3.3% and 3.9%. Soils from CAP showed a soil nutrient exhaustion of Fe, Mn and Mo, although the highest protein and sucrose contents in the leaves was observed in plants growing in those soils. Protein, lipids and carbohydrates concentrations differed according to sampling site, reflecting different production practices.