engleski

Major minerals in teas (green, black, fruit, herbal)

Tea is, next to water, the most widely consumed beverage worldwide. It contains many important substances and elements for the human health. Apart from flavonoids (polyphenols, tanning agents), caffeine, amino acids, volatile oils and vitamins (A, B1, B2, C and K), tea leaves also contain several minerals as aluminium, calcium, fluorine, iron, sodium, magnesium, manganese, potassium and zinc. Especially green tea contains a lot of potassium, an element important for healthy muscles (also for a strong heart), magnesium and manganese (important as activators for enzymes in the cell metabolism) and zinc (for the right functioning of the metabolism). Aluminium, though, is in contrast to the stimulating effect of plant growth, a powerful neurotoxicant for humans. In this investigation the mineral content of several samples of different kinds of tea (black tea, green tea, fruit tea and herbal tea) have been determined. Tea powder from tea bags have been used as raw materials. The dry mass content has been measured. After a microwave assisted digestion, the element concentrations have been determined with ICP-OES (inductively coupled plasma-optical emission spectroscopy). Additionally, tea infusions have been freshly prepared and their element concentrations have been analyzed. In all samples high amounts of calcium and magnesium could be found. And, as expected, differences in the elemental composition could be seen between the different classes of teas. Green and black tea contain more aluminium and manganese than fruit or herbal teas. Sodium is contained especially in herbal tea.

mineral ; tea ; ICP-AES

nije evidentirano