MINERAL COMPOSITION OF SOME EDIBLE FLOWERS

Flowers are grown not only for their ornamental values but also for the nutritive, medicinal, culinary, cosmetic and aromatic properties. They are a rich source of many chemical compounds which play an important role in various metabolic processes in the human body. Among them are minerals. The aim of the study, conducted in 2014-2015, was to determine and compare the content of macro- (N, P, K, Na, Ca, Mg, S), microelements (Fe, Zn, Cu, Mn) and heavy metals (Ni, Pb, Co, Cd) in flowers of different species and cultivars of ornamental plants. The experimental material consisted of dried flowers of Mimulus x hybridus L. (Magic Yellow, Magic Red). Antirrhinum majus L. (Cavalier), Dianthus chinensis L. (Chianti), Hemerocallis x hybrida Hort., Paeonia officinalis L. (Sarah Bernardt, Dr Aleksander Fleming, Karl Rosenfield). Monarda didyma L., Monarda fistulosa L. and Monarda citriodora subsp. austromontana Cerv. ex Lag. (Bees Favourite). The content of nitrogen was assessed by the Kjeldahls method, phosphorus - by the colorimetric method, potassium, sodium - by the flame photometry method, calcium, magnesium, sulphur, iron, zinc, copper, manganese, nickel, lead, cobalt and cadmium - by the method of atomic absorption spectrophotometry (AAS). The results of the chemical analyses showed that Monarda and Mimulus x hybridus L. flowers were characterised by a significantly higher content of macro- and microelements in comparison with the other species. Among the macroelements, the highest amounts were noted for potassium (on average 30.03 g kg(-1) d.m.), and from microelements - for iron (on average 154.93 mg kg(-1 )d.m.). Moreover, the edible flower species were characterised by a relatively low concentration of heavy metals: 2.297 mg Ni, 1.298 mg Pb, 0.723 mg Co and 0.342 mg Cd per kg of dry matter on average. The lowest amounts of heavy metals were found in flowers of Paeonia officinalis L. cultivars.