OBJECTIVE: The objective of this study was to assess the quality of two commercial brands of green tea in sachets, verifying how different infusion times, including that recommended by the manufacturer, affect functional component levels. METHODS: High-performance liquid chromatography with diode-array detection was used for identifying and quantifying caffeine, catechin, epigallocatechin, rutin and epicatechin. RESULTS: Epigallocatechin and catechin levels of both brands were higher with an infusion time of 6 minutes in boiling water (100°C). Rutin was only found in one of the brands after an infusion of six minutes. Methanol (99.8%) extraction significantly increased the yield of all study compounds. The Trolox Equivalent Antioxidant Capacity of the tea increased with infusion time. However, the Trolox Equivalent Antioxidant Capacity of the methanol extractions was significantly smaller than that of all of the other treatments (p<0.05). CONCLUSION: Chemical analysis of moisture, ash, ash insoluble in hydrochloric acid, and microscopic analysis of dirt and other physical contaminants showed that both brands conform to the legislation with respect to these parameters.
Antioxidantes; Camellia sinensis; Flavonoids; Quality management
