Department of Food and Nutrition, Medical University of Lublin, 4a Chodźki Str., 20-093 Lublin, Poland.
Department of Pharmacognosy with Garden of Medicinal Plants, Medical University of Lublin, 1 Chodźki Str., 20-093 Lublin, Poland.
Molecules. 2021 Oct 4;26(19):6017. doi: 10.3390/molecules26196017.
A comprehensive approach to the mineral composition of black teas of different origins was studied using the Flame Atomic Absorption Spectrometry (FAAS) method, supported by chemometric tools including Principal Component Analysis PCA) and Classification and Regression Trees (CART). Significant differences between the teas from seven countries (Japan, Nepal, Kenya, Iran, Sri Lanka, India, and China) were shown. K was the main element determined in all teas, with an average concentration of 11,649 mg/kg, followed by Ca, Mg and Mn. In general, regarding all investigated black teas, the element content was ranked in the following order: K > Ca > Mg > Mn > Fe > Na > Zn > Cu. The applied chemometric methods allowed us to recognize black tea clusters based on their mineral composition and place of cultivation, and allowed us to find correlations between particular elements in black teas. The performed analyses revealed interesting correlations between the concentration of various elements in black teas: K was negatively correlated with Na, Fe, Mn and Cu; K was positively correlated with the content of Ca and Mg. Significant positive correlations between Mn and Fe and Mn and Zn in the studied black tea samples were also revealed. It was shown that mineral composition may be a significant factor regarding the origin of the black tea, not only considering the country, but also the region or province.
采用火焰原子吸收光谱法（FAAS）并结合主成分分析（PCA）和分类回归树（CART）等化学计量学工具，对来自 7 个国家（日本、尼泊尔、肯尼亚、伊朗、斯里兰卡、印度和中国）的红茶的矿物组成进行了全面研究。结果表明，来自不同国家的茶之间存在显著差异。K 是所有茶中含量最高的元素，平均浓度为 11649mg/kg，其次是 Ca、Mg 和 Mn。总体而言，在所研究的所有红茶中，元素含量的排序为：K > Ca > Mg > Mn > Fe > Na > Zn > Cu。应用的化学计量学方法允许我们根据其矿物组成和种植地点识别红茶聚类，并发现红茶中特定元素之间的相关性。分析结果揭示了红茶中各种元素之间的有趣相关性：K 与 Na、Fe、Mn 和 Cu 呈负相关；K 与 Ca 和 Mg 的含量呈正相关。在研究的红茶样本中，Mn 和 Fe 之间以及 Mn 和 Zn 之间也显示出显著的正相关关系。研究表明，矿物成分可能是红茶起源的一个重要因素，不仅要考虑国家，还要考虑地区或省份。
