Enhancing the Antioxidant Activity of Tea (Camellia sinensis) Through Common Herbal Infusions

Abstract

Tea is the second most widely consumed beverage globally, after water, and is known for its substantial antioxidant properties, primarily due to its phenolic content. This study quantifies phenolic compounds and assesses antioxidant activity in ten types of tea and selected herbal infusions, individually and in combination. Our findings reveal that free phenolic compounds and their antioxidant activity were twelve times and eight times greater than bound phenolic compounds. Among individual infusions, white tea exhibited the highest antioxidant activity and phenolic content, with 172.51 µmol TE/1000 g and 7.83 mg GAE/1000 g, respectively. In combination, white/linden flower tea showed the highest antioxidant activity (374.44 µmol TE/1000 g), and white/orange tea contained the highest phenolic content (9.24 mg GAE/1000 g). This study identified primarily two phenolic compounds, epigallocatechin gallate and epicatechin gallate, and one alkaloid, caffeine, in tea and herbal combinations. Compared to other combinations, we observed significant variations in catechins and caffeine between white and dark teas. Integrating specific herbal infusions with tea can enhance antioxidant activity up to three-fold compared to tea alone. This research offers valuable insights into optimizing herbal infusions to maximize antioxidant benefits, creating new opportunities to enhance the health benefits of tea-based products.