Effect of Different Brewing Methods on Quality of Green Tea

Abstract

Tea infusions were prepared from cold or hot brewed-parched or steamed green tea at 2, 6 and 10% and their color properties; several components and sensory scores were measured. Tea infusions from both green tea were comparable in contents of soluble solids, sugars, free amino acids, caffeine and antioxidant components, and had different pH values, profiles of various catechins, colors and sensory results. Higher ratios (tea leaves/water) resulted in higher soluble component contents in tea infusions but lower sensory results. Cold brewing of lower extraction efficacy resulted in lighter, less colored and higher sensory-rated tea infusions with less astringent and bitter taste. Five of 12 different tea infusions were highly rated and were in the descending order of 2%-cold, 2%-hot, 6%-cold brewed infusions from parched green tea, and 2%-cold and 2%-hot brewed infusions from steamed green tea. Overall, cold brewed tea infusions from parched green tea would be a new alternative. Practical Application Green tea includes the Japanese style steamed tea and the Chinese style parched (fired) tea with the difference in blanching. This research disclosed herein were the information about the influence of different brewing temperatures (cold or hot water) on the quality of tea infusions brewed from different green tea (parched or steamed) at different concentrations (2, 6 or 10%). Tea infusions from parched and steamed green tea were comparable in contents of soluble solids, sugars, free amino acids, caffeine and antioxidant components, and had different pH values, profiles of various catechins, colors, and sensory results. Cold brewing of lower extraction efficacy resulted in lighter, less colored and higher sensory-rated tea infusions. Cold brewed tea infusions contained lower contents of caffeine, epigallocatechin gallate and epigallocatechin, and were less astringent and bitter. Overall, cold brewed tea infusions from parched green tea would be a new alternative to the public.