Brewing Time and Lemon Juice as Factors Affecting the Elemental Composition in Commercial Tea Infusions

Area of Science:

• Food Science and Technology
• Environmental Chemistry
• Nutritional Science

Background:

• Tea is a globally popular beverage with potential for dietary exposure to essential and toxic elements.
• Understanding how preparation methods influence the elemental composition of tea is crucial for dietary exposure assessment.

Purpose of the Study:

• To investigate the impact of brewing time and lemon juice addition on metal concentrations in black tea infusions.
• To analyze the multivariate relationships among selected metals under different brewing conditions.

Main Methods:

• Commercial black tea was brewed under varying times and with/without lemon juice.
• Concentrations of selected metals (Pb, Cd, Mn, Al, Cr, Zn, Cu, Ni) were measured.
• Principal Component Analysis (PCA) was employed to assess elemental profile changes.

Main Results:

• Brewing time affected Pb, Cd, Mn, and Al; lemon juice addition influenced Pb, Cr, Zn, Cu, Mn, and Al.
• Extended brewing increased Mn and Al but decreased Pb and Cd.
• Acidification enhanced Al, Mn, Zn, Cr, and decreased Cu; acidification had a stronger effect than brewing time.
• Tea infusions were a substantial source of Mn (30-60% of adequate intake).

Conclusions:

• Common brewing practices, particularly acidification, significantly alter the elemental profile of black tea.
• The investigated teas pose no significant health risk and can be a beneficial source of manganese.
• Preparation methods are key determinants of metal bioavailability and dietary exposure from tea.