Tea as a Source of Biologically Active Compounds in the Human Diet

Abstract

Due to the different levels of bioactive compounds in tea reported in the literature, the aim of this study was to determine whether commercially available leaf teas could be an important source of phenolics and selected minerals (copper, manganese, iron, zinc, magnesium, calcium, sodium, potassium) and if the differences in the content of these components between various types of tea are significant. It was found that both the amount of these compounds in tea and the antioxidant activity of tea infusions were largely determined by the origin of tea leaves as well as the processing method, which can modify the content of the studied components up to several hundred-fold. The group of green teas was the best source of phenolic compounds (110.73 mg/100 mL) and magnesium (1885 µg/100 mL) and was also characterised by the highest antioxidant activity (59.02%). This type of tea is a great contributor to the daily intake of the studied components. The average consumption of green tea infusions, assumed to be 3–4 cups (1 L) a day, provides the body with health-promoting polyphenol levels significantly exceeding the recommended daily dose. Moreover, drinking one litre of an unfermented tea infusion provides more than three times the recommended daily intake of manganese. Tea infusions can be a fairly adequate, but only a supplementary, source of potassium, zinc, magnesium, and copper in the diet. Moreover, it could be concluded that the antioxidant activity of all the analysed types of tea infusions results not only from the high content of phenolic compounds and manganese but is also related to the presence of magnesium and potassium.

Process optimization for the development of fruit‐based diet drink: A low‐calorie approach

“…On the other hand, herb extract also contributed significantly ( p ≤ .05) to the sodium content of DDs which might be due to the presence of sodium in a ginger root, that is, 38.96 μg/g (Ogbuewu et al, 2014). Tea extract concentration affects potassium content of DDs inversely (Table 3) owing to its contribution in tea, that is, 30,362 μg/ 100 ml (Klepacka et al, 2021). However, the potassium content increased with an increase in herb extract concentration because ginger is a good source of essential micronutrients such as potassium, magnesium, copper, and manganese (Bhatt et al, 2013).…”

The effect of Camellia sinensis tea on a decreased risk of anxiety for medical students at Universitas Lambung Mangkurat Indonesia

“…Red and green teas are rich sources of antioxidants, particularly flavonoids. 16,17 A study using Ethiopian tea leaves demonstrated that level of L-theanine in green teas are higher than black ones by > 48 mg/g and by < 31 mg/g of dried aqueous extract, respectively. 18…”

Mini-Review on the Enzymatic Lipophilization of Phenolics Present in Plant Extracts with the Special Emphasis on Anthocyanins

“…Tea is one of the most popular beverages consumed around the globe and prepared from the leaves of Camellia sinensis. The beneficial effect of tea on human health is primarily due to its high antioxidant activity, which results mainly from the presence of tannins and catechins (epicatechin, epigallocatechin), as well as their derivatives (epicatechin gallate and epigallocatechin gallate) [ 37 , 38 , 39 ]. Seeds are another product in addition to the leaves of the tea plant; they are the source of vegetable oil, an important plant oil due to its high content of unsaturated fatty acids, especially essential linoleic acid.…”