Quality and Antioxidant Property of Three Types of Tea Infusions

Abstract

Tea infusions were prepared from green, oolong and black teas made from the leaves of Camellia sinensis L. (cultivar Shy‐Jih‐Chun) using the conventional brewing procedure. Three types of tea infusions were different in pH values, soluble solids, color values and visual appearance. With regard to antioxidant activity, reducing power and scavenging ability, the efficacies of tea infusions were in the descending order of nonfermented > semi‐fermented > fully fermented. However, the order of efficacies in chelating ability was reversed. Besides, black tea infusion showed a higher Trolox equivalent antioxidant capacity value. Caffeine contents were similar (42.43–43.13 mg/100 mL). Contents of ascorbic acid, total phenols and total catechins were in the descending order of green > oolong > black tea infusions. All sensory scores (>4.5) were in the descending order of oolong > black > green tea infusions. Overall, the results were valuable for further application and comparison. Practical Application Three different types of tea infusions were brewed from green, oolong and black teas, which were made from the same tea variety. This research disclosed herein the information about the influence of different tea‐making processes (unfermented, partially fermented and completely fermented) on the quality of tea infusions brewed using the conventional brewing procedure. It seems that differences in the degrees of fermentation resulted in different pH values, soluble solids, color values and visual appearance of tea infusions. Three tea infusions were effective in antioxidant properties, including antioxidant activity, reducing power, scavenging ability on radicals and chelating ability on ferrous ions. Caffeine contents were similar in three types of tea infusions. Three tea infusions were sensory acceptable. Overall, the results of three different types of tea infusions were valuable for further application.

High Levels of Major Components and Antioxidant Activity of Fermented Tea Treated with Lactococcus lactis subsp. cremoris

“…Generally, the progress of fermentation by an LAB involves a significant decrease in pH due to the production of lactic acid [14]. In this study, the pH did not dramatically decrease over 14 days as shown Fig.…”

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

“…Soluble carbohydrates in green tea infusions maybe fructose, glucose, and sucrose which are responsible for the sweet taste of the brew. On the contrary, monosodium glutamate-like amino acids found in the brew are accountable for umami taste [ 34 ]. The amounts of extractable substances that are steeped into the tea brew is one of the important characteristics of green tea which determines the quality of green tea.…”

Physicochemical Parameters, Mineral Composition, and Nutraceutical Properties of Ready-to-Drink Flavored-Colored Commercial Teas

“…Lin et al [31] prepared infusion of green, oolong, and black teas by mixing 3 g of tea dried tea leaves with 150 mL of boiling water for 5 min, and after that, the sample was cooled to room temperature to measure the total phenols content and antioxidant capacity levels. Results obtained by these authors were higher than our results with 920, 745, and 669 mg·L −1 of total phenols in of green, oolong, and black teas, respectively.…”