This study investigated how the temperature of the hot water extraction (70–100 °C) affects the yield of phenolic compounds, catechin composition, and the antioxidant potential of tea infusions. UHPLC-DAD analysis showed that extraction efficiency increased with temperature, with the highest total phenolic content (TPC) and catechin levels obtained at 80–90 °C. However, a slight decline in selected epistructured catechins above 90 °C indicated thermally induced degradation or epimerisation. The infusions with the highest phenolic content were then spray-dried with maltodextrin to produce stable encapsulated powders. These microencapsulated powders exhibited low moisture content, water solubility and high phenolic content. The inhibitory activity of the encapsulated powders against acetylcholinesterase and tyrosinase - enzymes associated with cognitive impairment and skin pigmentation abnormalities - was assessed in vitro. The inhibitory effect was observed against acetylcholinesterase (AChE), with half-maximal inhibitory concentration (IC 50 ) values ranging from 3.3 to 20.0 mg/mL. Moderate negative correlation was observed between caffeine content and IC 50 values. In other words, the higher the caffeine content the stronger the inhibitory effect on AChE. To explore potential applications in functional food products, the encapsulated powders were incorporated into vegan, agar-based gummies at a concentration of 1%. The incorporation of spray-dried tea encapsulates into vegan gummies enhanced their phenolic content and antioxidant capacity, highlighting their potential as functional food ingredients. • Temperature significantly affects the extraction of bioactive compounds from white, green, and black tea. • The optimal extraction temperature for hot water is between 80 and 90 °C. • Microencapsulation effectively preserves phenolic compounds and antioxidant activity. • Encapsulated tea extracts inhibit acetylcholinesterase and tyrosinase in vitro. • Vegan gummies enriched with encapsulated tea extracts show improved sensory and bioactive qualities.
Kulbat-Warycha et al. (Sun,) studied this question.