Phenolic compounds profile and caffeine in espresso machine extracted teas and capsule coffees: evaluation of...

Capsule coffees are well-established globally, and capsule teas are gaining ground as an alternative beverage to coffee and caffeine consumption. However, the bioactive phenolic potential of capsule teas extracted in espresso machines must be elucidated. In this study, 10 coffees and 14 commercial monovarietal and blended teas in capsules were extracted using an espresso machine (pressure ≤ 18 bar; 80 °C; volume of 100 mL) to evaluate their phenolic profile and caffeine content, and then subjected to simulated digestion to assess bioaccessibility. The coffees stood out for their higher values of phenolic acids, such as chlorogenic acid, compared to the teas. They also had epigallocatechin gallate (0.63-1.85 mg/100 mL), procyanidin B2 (0.26-0.65 mg/100 mL), myricetin (0.88-4.81 mg/100 mL), and naringenin (0.11-1.53 mg/100 mL). The blended teas had a greater diversity of phenolic classes, such as anthocyanins, in capsules that used flowers, hibiscus, and red fruits. Camellia sinensis teas had the highest bioactive content and were associated with gallic acid (1.93 to 2.35 mg/100 mL), catechin (5.07 to 12.9 mg/100 mL), and epicatechin (1.24 to 3.5 mg/100 mL). The blended tea containing Camellia sinensis exhibited good bioaccessibility levels, particularly for epigallocatechin gallate (871.8 %) and kaempferol 3-glucoside (862.5 %). Notably, caffeine was also bioaccessible (80.1 %), which may limit its use in caffeine-restricted diets. Our results suggest that the teas extracted in espresso machines preserved antioxidant substances associated with beneficial effects on consumers' health.