Abstract
Brewing temperature and duration jointly modulate the sensory perception, functional properties and chemical profiles of herbal tea infusions, yet their integrated effects on Cyclocarya paliurus tea remain poorly understood. In this study, cold-brewed (4 °C) and hot-brewed (90 °C) C. paliurus infusions were prepared across a time gradient from 5 min to 2 h, and systematically characterized via a multi-platform analytical strategy.Hot brewing produced darker infusions with stronger bitterness and astringency, higher levels of phenolics and flavonoids, and greater DPPH(2,2-diphenyl-1-picrylhydrazyl ) and ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical-scavenging capacity, whereas cold brewing resulted in lighter appearance, milder taste and more gradual time-dependent compositional changes. A total of 61 volatile features and 3666 metabolite features were annotated, with 50 core differential metabolites screened. Representative metabolites including gossypetin 8-glucuronide, kaempferol 3-O-arabinoside, sericoside and epoxypheophorbide a were statistically associated with antioxidant, bitterness and color traits, respectively.These results demonstrate compound-specific temperature- and time-dependent responses rather than simplistic greater extraction under high temperature, providing chemical clues for brewing optimization and development of differentiated C. paliurus-based herbal beverages.