Investigation of the Impact of Different Types of Brewing Water on Green Tea Infusion Quality Based on <scp>RATA</scp> and <scp>GC</scp> – <scp>MS</scp>

ABSTRACT This study examines the effects of four different types of brewing water, including purified water (PW), natural water (NW), natural mineral water (NMW) and electrolysed water obtained (EW) on the release of aroma compounds in green tea infusions through consumer‐based sensory evaluation Rate‐All‐That‐Apply (RATA) and GC–MS analysis. The research results indicated that tea infusions brewed with PW at pH 7.13 contain the highest levels of volatile compounds (527.84 μg/kg), tea polyphenols (18.83%) and soluble sugars (9.20%). In contrast, those brewed with alkaline EW at pH 9.15 exhibited the lowest levels. The RATA results indicated that consumers can distinctly perceive differences between tea infusions prepared with different brewing water. Tea infusions prepared with NW at pH 7.71 were the most preferred. The floral and chestnut aromas of the tea infusions were initially higher as the pH of the brewing water increased, followed by a decline, while the tend aroma weakened and the dull odour increased. The bitterness and astringency were more prominent in tea infusions prepared using NMW and EW. Partial least squares regression (PLSR) analysis identified α‐terpineol, decanal, nonanoic acid, benzophenone, nonanal and 1‐tetradecanol as key contributors to ‘flowery aroma’ and ‘chestnut aroma,’ with higher concentrations of these compounds correlating with increased consumers' preference for tea infusions. These substances were abundant in tea infusions prepared with PW and NW. Additionally, an analysis of the effect of different concentrations of SiO 3 2− in aqueous solutions on green tea infusion flavour indicated that SiO 3 2− promotes the release of alcoholic compounds in tea infusions, thereby improving the overall fragrance of the tea. The tea infusions T1 and T2, prepared using PW and NW respectively, demonstrated superior consumer acceptability due to their well‐balanced flavour profile and harmonious taste characteristics, making PW and NW particularly suitable for green tea preparation. These results provide valuable insights into the effects of different brewing water types on green tea's flavour quality.