Effect of the type of brewing water on the sensory and physicochemical properties of light-scented and strong-scented Tieguanyin oolong teas.

Variations in the quality of brewing water profoundly impact tea flavor. This study systematically investigated the effects of four common water sources, including pure water (PW), mountain spring water (MSW), mineral water (MW) and natural water (NW) on the flavor of Tieguanyin tea infusion. Brewing with MW resulted in a flat taste and turbid aroma, mainly due to the low leaching of tea flavor components and complex interactions with mineral ions (mainly Ca2+, Mg2+). Tea infusions brewed with NW exhibited the highest relative contents of total volatile compounds, while those brewed with PW had the lowest. NW and MSW, with moderate mineralization, were conducive to improving the aroma quality of tea infusion and were more suitable for brewing both aroma types of Tieguanyin. These findings offer valuable insights into the effect of brewing water on the sensory and physicochemical properties of oolong teas.

Effects of brewing water on the volatile composition of tea infusions.

There is a huge demand for brewing water in tea consumption, and the sensory flavor of tea infusion is significantly affected by the water used for brewing. To investigate the impact of brewing water on the aroma of tea infusions made from Camelia senensis, the three tea infusions of green, oolong and black tea brewed by six different drinking waters were analyzed by sensory evaluation, solid-phase microextraction, gas chromatography-mass spectrometry, and chemometrics. Brewing water with high pH values (>8.10) and high TDS content (>140 ppm) resulted in a lower overall aroma acceptability for tea infusion, where HCO3-, Ca2+ and Mg2+ were key influencing ions. A total of 86, 106, and 131 volatiles were identified in green, oolong and black tea infusions, respectively, which were strongly influenced by six different brands of waters. Decanal, dimethyl sulfide, ß-ionone and linalool were potent volatiles in tea aroma changes caused by brewing water.

The types of brewing water affect tea infusion flavor by changing the tea mineral dissolution.

The effects of different brewing water samples, including natural drinking water (NDW), pure water (PW), mineral water (MW), distilled water (DW), and tap water (TW) on flavor and quality of green tea infusion were investigated. The results showed the dissolution rate of mineral substances varied greatly depend on the type of water used. Notably, the tea infusion brewed with MW showed the highest taste response and darker but higher brightness in color. Furthermore, the content of volatile compounds was highest in tea infusion brewed with NDW and lowest in tea infusion brewed with MW. The mineral substances content and pH were the main factors affecting volatile compounds in green tea infusion. Thereinto, Ca2+ and Fe3+ remarkably affected the content of alcohols and aldehydes in volatile compounds. These results suggested that water with a neutral pH value and lower mineral substance content is more conducive for brewing green tea.

Quality characteristics of green Tea's infusion as influenced by brands and types of brewing water.

The influences of four types of brewing waters including tap water (TAP), alkaline ionized water (ALK), magnetized water (MAG) and mineral water (MIN), and two brands of commercial green tea (L and T) on quality characteristics of tea infusions were studied. The Oxidation Reduction Potential (ORP) values of the brewing waters was TAP > MAG, MIN > ALK. After brewing, all infusions showed a significant drop (p < 0.05) in pH values. The pH of original brewing waters of ALK (8.64) was the highest as compared to other waters, whereas L-MIN (pH 6.63) and T-MIN (pH 5.82) showed the highest pH values after brewing. Overall, the quality characteristics of green tea infusions were influenced by the brands of tea and the types of brewing water used. MAG was the most superior brewing water in extracting the green tea. Evidenced by total phenolic and flavonoids contents, both L-MAG and T-MAG infusions were superior in extracting antioxidative compounds as compared to other tea infusions. In addition, T-MAG infusion was the least astringent (P < 0.05) and scored the highest (P < 0.05) overall acceptability ( 5.40 ) by sensory panelists.

Unraveling the difference in aroma characteristics of Huangjiu from Shaoxing region fermented with different brewing water, using descriptive sensory analysis, comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry and multivariate data analysis.

To investigate the specific difference in aroma characteristics of Huangjiu (Chinese rice wine) in Shaoxing region fermented with different brewing water, descriptive sensory analysis, comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS) and multivariate statistical analysis were employed. The descriptive sensory analysis proved that Huangjiu fermented with Jianhu water had higher overall aroma intensity, and was more prominent in ester, sweet and alcoholic aroma than those fermented with deionized water and Nenjiang water. The results of aroma components analysis by GC × GC-qMS showed that the Huangjiu fermented with Jianhu water had higher concentration of some key aroma compounds, such as ethyl butyrate (OAV: 29-196), isoamyl acetate (OAV: 11-18) and ethyl hexanoate (OAV: 38-47). The multivariate statistical analysis further confirmed that 14 compounds could be used as key markers to distinguish the Huangjiu samples fermented with different brewing water. The correlation network between the volatile compounds in Huangjiu and the inorganic components in water indicated that the ions played an important role in the formation of the difference in aroma characteristics among the samples.

Effects of brewing water on the sensory attributes and physicochemical properties of tea infusions.

The effects of brewing water on the sensory attributes and physicochemical properties of tea infusions made from Chinese teas were investigated. The tea infusions brewed in water with higher pH and total dissolved solids (TDS), generally had a darker color and lower overall sensory acceptability. Moreover, those infusions had less catechins, particularly galloylated-catechins, and lower antioxidant capacity. The teas with less fermentation contained more galloylated-catechins and had higher antioxidant capacity, but were much more susceptible to high mineral brewing water. Green tea was proved to be the most susceptible one, whereas dark tea the most stable one. Green tea infusions prepared with higher pH/TDS water were more rapidly oxidized, resulting in a darker color due to polymerization of catechins, when exposed to the air. These findings suggested that low mineral brewing water was better for Chinese tea, both from the sensory and health benefit perspectives.

Effect of the type of brewing water on the chemical composition, sensory quality and antioxidant capacity of Chinese teas.

The physicochemical characteristics, sensory quality, and antioxidant activity of tea infusions prepared with purified water (PW), mineral water (MW), mountain spring water (MSW), and tap water (TW) from Hangzhou were investigated. The results showed that the taste quality, catechin concentration, and antioxidant capacity of green, oolong, and black tea infusions prepared using MW and TW were significantly lower than those prepared using PW. Extraction of catechins and caffeine was reduced with high-conductivity water, while high pH influenced the stability of catechins. PW and MSW were more suitable for brewing green and oolong teas, while MSW, with low pH and moderate ion concentration, was the most suitable water for brewing black tea. Lowering the pH of mineral water partially improved the taste quality and increased the concentration of catechins in the infusions. These results aid selection of the most appropriate water for brewing Chinese teas.