Levels of essential and non-essential elements in black teas commercialized in Poland and their transfer to tea infusion

Oxalate, magnesium and calcium content in selected kinds of tea: impact on human health

“…In our study, magnesium characterized with the highest percentage of leaching, especially in green (37 %) and black tea (34 %) ( Table 2). The latter is comparable with values reported by Dambiec et al [42]. Calcium was poorly extractable (7-15 %), similarly to what was suggested by Szymczycha-Madeja et al [35].…”

Determination of essential and non-essential elements in green and black teas by FAAS and ICP OES simplified – multivariate classification of different tea products

“…The consumption of tea beverages per capita in the Europe is also high [1]. It is therefore not surprising that the interest in the information about the content of metals in different tea receives a great deal of attention and continuous to grow in many European [3,7,8], Asiatic [4,9] and African [10] countries. This is mostly due to a nutritional value of essential metals and beneficial prohealthy properties of tea [11], on one side, as well as a risk of an excessive exposure to non-essential and heavy metals and toxicological adverse effects related to the intake of tea [10], on the other side.…”

“…Flame atomic absorption spectrometry (FAAS) [2,7,[9][10][11]16,17] as well as inductively coupled plasma optical emission spectrometry (ICP OES) [5,6,13,14,[17][18][19][20] are the most popular spectrochemical techniques extensively used for the determination of metals in tea. Unfortunately, both FAAS and ICP OES require samples of tea to be decomposed to release analytes; hence, the time of the analysis and the quality of Microchemical Journal 121 (2015) 122-129 results strongly depend on the quality and reliability of the sample preparation step used before the spectrochemical analysis.…”

“…Unfortunately, both FAAS and ICP OES require samples of tea to be decomposed to release analytes; hence, the time of the analysis and the quality of Microchemical Journal 121 (2015) 122-129 results strongly depend on the quality and reliability of the sample preparation step used before the spectrochemical analysis. Sample preparation procedures used in case of FAAS and ICP OES are based on the wet oxidative digestion in open-vessel [2,[5][6][7]10,11,19,20] and closed-vessel [9,14,18] systems. Reagents applied are aqua regia [2,10], HNO 3 [18], HNO 3 with 30% H 2 O 2 (5 + 1) [7], (6 + 1) [14] or (6 + 2) [9], HNO 3 with HClO 4 (6 + 4) [6], (7 + 3) [20], (9 + 1) [19] or (10 + 1) [5], HNO 3 with HCl (2:1) and 30% H 2 O 2 (7 + 2) [11].…”

Sensitive chemical sensor array based on nanozymes for discrimination of metal ions and teas

“…Except for polyphenols, there are many other compounds in tea, such as fluoride, caffeine, and essential minerals, that are beneficial for human health . Drinking tea satisfies the need for some essential minerals in the daily diet .…”