Influence of Different Brewing Water on the Quality of Huiming Tea Infusions

This research tested six Huiming tea infusions brewing by different types of water,including pure water(PW),bottled natural water(TR1,TR2),bottled mineral water(MW1,MW2)and tap water(TW). Comparisons had been made between their physicochemical characteristics,biochemical components,and sensory qualities. It also adopted solid-phase microextraction(SPME)combined with gas chromatography-mass spectrometry(GC-MS)to analyze aroma components. The results indicated that different types of water had significant effects on both the physical and chemical properties of Huiming tea infusions. Comparing with TR1,TR2,and PW tea infusions,MW1,MW2,and TW tea infusions with high Ca²⁺,Mg²⁺ ions had a lower increment of Mg²⁺ ion or electrical conductivity. Meanwhile,the concentration of Ca²⁺ ion in MW1,MW2,and TW also significantly reduced. For taste-producing substances,free amino acid and Ca²⁺,Mg²⁺,pH,also total soluble sugur and pH,as well as tea polyphenols and Ca²⁺,Mg²⁺,pH,electrical conductivity had a very significant negative conelation(P<0.01). As for aroma compounds,the contents in TR1(7429 μg·kg^-1)and PW(7422 μg·kg^-1)tea infusions were significantly higher than other samples(about 5100 μg·kg^-1). Further,it also found that most aroma compounds had significant negative correlations(P<0.05)with Ca²⁺ ion and pH of the water,as well as positive correlations(P<0.05)with total soluble sugar and free amino acids. At last,for the sensory qualities,the evaluation granted TR1 and TR2 tea infusions of the most favorite among all samples. In detail,TR2 infusion had a more favorable color and taste when TR1 infusion had the best fragrance quality. Therefore,the lower the pH and Ca²⁺ concentration of water,the higher the content of aroma substances,and the better the aroma quality of tea infusions.