Seasonal variation in nutrient content of some leafy vegetables from Banat County, Romania

The aim of this study is to investigate the effect of seasonal variation of the moisture content and trace metal composition of spinach, butter lettuce and parsley leaves. The content of bioactive compounds in green leafy vegetables at harvest has beneficial effects on human health. It was found that moisture, macro and microelement content vary from one season to another. Water content measured by thermo-gravimetric method is presenting small variation during the seasonal change, revealing the lowest value for spinach, butter lettuce and parsley leaves, in June. Calcium, magnesium and potassium concentrations in leaves are decreasing in spinach, lettuce and parsley from April to September, but the variations are small. Copper is accumulating mostly in parsley leaves and less in lettuce and spinach. Knowing the concentration of important nutrients in different seasons helps do decide the harvesting period in according to the richness of the diet for each individual.