Tea (Camellia sinensis L.) infusion is the second most commonly consumed drink in the world after water, valued for its sensory qualities and health-promoting properties. Tea contains a range of chemical compounds that give it specific nutritional and refreshing properties. These include alkaloids, polyphenolic compounds, carbohydrates, amino acids, enzymes, and aromatic compounds. The content of individual compounds in tea leaves is impacted by factors such as the variety, region, and cultivation method, as well as specific processing operations. The aim of the present study was to investigate the content of bioactive compounds in a selection of organic and conventional tea infusions characterized by different degrees of leaf fragmentation. The analysis of selected phenolic acids, catechins, quercetin, and caffeine in black tea and black Earl Grey tea infusions was conducted using high-performance liquid chromatography (HPLC). The study confirmed that the chemical composition of tea infusions is significantly impacted by the type of tea, cultivation practices, and form of the leaves, and revealed some previously underexplored interactions between the leaf fragmentation and cultivation system effects. From a consumer or product design perspective, organic loose-leaf Earl Grey teas appear to offer the most favourable balance of catechins, and flavonoids whereas conventional bagged black teas provide higher phenolic acid content.
Kazimierczak et al. (Sat,) studied this question.