Despite extensive global research on Camellia sinensis, comprehensive studies on its chemical composition remain limited in many regions, including Saudi Arabia, restricting insights into its health benefits and quality. This study aimed to characterize the mineral, antioxidant, phenolic, and phytochemical profiles of 20 commercial tea brands imported from Sri Lanka, India, the United Arab Emirates, Saudi Arabia, and the United Kingdom. Mineral content was assessed via inductively coupled plasma mass spectrometry (ICP-MS), phytochemicals were analyzed by gas chromatography-mass spectrometry (GC-MS), antioxidant capacity was evaluated using the DPPH assay, and total phenolic content (TPC) was determined with the Folin-Ciocalteu method. Chemometric analyses, including principal component analysis (PCA) and hierarchical cluster analysis (HCA), were used to explore variable associations and sample groupings. Aluminum (4.42 × 10³ to 1.70 × 10⁴ ppb) and manganese (2.80 × 10³ to 3.46 × 10³ ppb) showed notable variability, with elevated lead (6000 ppb) and cadmium (52.5 ppb) in one sample indicating potential contamination risks. Caffeine (57.76-79.14%) was the dominant phytochemical, followed by theobromine and quinic acid. Although TPC ranged from 256.22 to 361.84 mg GAE/mL, it showed no clear correlation with DPPH inhibition (11-69%), suggesting contributions from non-phenolic antioxidants. PCA and HCA indicated both geochemical and anthropogenic influences on sample composition. These findings underscore the chemical diversity of tea in the Saudi market and support the need for strengthened quality control. Future studies should quantify specific phytochemicals and identify contamination sources to enhance the safety and nutritional value of these products.
Taha et al. (Fri,) studied this question.