Total reflection X‐ray fluorescence analysis of elemental composition of herbal infusions and teas

Abstract

BACKGROUND The elemental composition of herbal infusions and teas has not been sufficiently investigated. It could potentially be used for defining fingerprints for individual herbal / tea infusions, differentiation of botanical families, detecting the influence of packaging, and other purposes. The objective of this study was to determine the elemental composition, including the trace element content, of various herbal infusions and teas by means of total reflection X‐ray fluorescence analysis (TXRF), with a chemometrics approach using principal component analysis (PCA). RESULTS This study determined the elemental composition of various herbal infusions and teas, including trace elements, using total reflection X‐ray fluorescence (TXRF). The methodology for the sample preparation was established, including the multiple‐steepings procedure for the two tea samples (Oolong and Pu‐erh). Data from 29 samples were collected. We hypothesized that the elemental content of infusions could reflect certain features, such as the influence of processing and the type of tea. CONCLUSION A chemometric approach (PCA) was applied, and differences between teas and herbal infusions were found. This was further corroborated by explicit differentiation of one botanical family, Theaceae. The influence of packaging (tea bags) on herbal material was identified. The three types of tea ( Camellia sinensis ) appeared to be separated with PCA, and elemental concentrations in Pu‐erh changed with multiple steepings.

Type of tea consumption and depressive symptoms in Chinese older adults

“…Daily consumption of one or more cups of green, fermented, or floral tea was associated with up to 50% lowered odds of having depressive symptoms. These findings are in line with previous observations of an inverse association of tea consumption with the risk of depression [ 22 – 27 ].…”

“…The association of tea consumption with depression is observed to be highly heterogeneous among studies and populations across the world, and is true within China, as evidenced by the data in this study. The heterogeneity may be partly explained by the local popularity of different types of tea used for consumption and methods of infusion and preparation in production [ 27 , 50 ]. In China, tea of different types is traditionally consumed on its own without or rarely with milk and remains so today, whereas tea, mostly of mixed blends of black fermented tea, is popularly consumed with milk in the West [ 51 ].…”

“…However, there remains a paucity of studies that examine the dose-response effect for different types of tea. Bioactive components, which vary in different types of tea through diverse processing methods in the markets, may account for the heterogeneity of findings [ 27 , 28 ]. Green tea has a higher content of catechins than fermented teas (such as Oolong and black teas).…”

Type of Tea Consumption and Depressive Symptoms in Older Adults

“…The heterogeneity may be partly explained by local popularity of different types of tea used for consumption and methods of infusion and preparation in production 28,51 . In China, tea of different types is traditionally consumed on its own without or rarely with milk and remains so today, whereas tea, mostly of mixed blends of black fermented tea, is popularly consumed with milk in the West 52 .…”

“…However, there remains a paucity of studies that examine dose-response effect for different types of tea. Bioactive components which vary in different types of tea through diverse processing methods in the markets may account for the heterogeneity of ndings 28,29 . Green tea has a higher content of catechins than fermented teas (such as Oolong and black teas).…”