Catechin Composition, Phenolic Content, and Antioxidant Properties of Commercially-Available Bagged, Gunpowder, and Matcha Green Teas

The leaves of the Camellia sinensis plant are used to produce many different types of teas, and green tea is particularly noted for its health promoting properties which are attributed to high concentrations of phenolic compounds known as catechins. Green tea is available in forms such as bagged, gunpowder (rolled leaf), and matcha, a fine powder. This study evaluated the phenolic content, catechin composition, caffeine concentration, and antioxidant properties of fifteen commercially-available green teas with an emphasis on identifying differences between ceremonial and culinary matcha. Gunpowder and bagged green teas had higher total phenolic contents and greater CUPRAC (cupric ion reducing antioxidant capacity) and ORAC (oxygen radical absorbance capacity) antioxidant capacities than matcha teas. Among matcha samples, less expensive culinary teas had greater total phenolic contents and higher antioxidant capacities than ceremonial products. Hierarchical cluster analysis was used to determine similarities and differences in catechin composition and revealed that bagged and gunpowder green teas had the highest levels of the stereoisomers epi/catechin gallate, which correlated with their strong antioxidant properties. Bagged and gunpowder teas were the lowest cost products in this study, indicating that they are an economical choice for consumers who want a green tea beverage with high catechin content, although they generally had lower caffeine levels than matcha.

An input-output model for resources planning in a medical care system

As medical care delivery systems grow in complexity, the understanding of interaction between entities within the system becomes a key aspect in resource planning. The model presented in this paper is geared to aiding resource planning both at the community or regional level and at the medical facility level. At the regional level the problem is related to the elimination of duplication and the sharing of services. At the medical facility level the concern is the balancing of the supply and demand of services among the departments. The framework of the model is a directed graph with nodes representing the service entities and branches representing the interrelationships. At the regional level, entities are hospitals, clinics, and centralized supportive units, such as the data center or the central laboratory. At the medical center level, entities are generally departments within the facility. An iterative procedure is used to simulate the propagation effect of a change on all entities. The model at the medical center level, as implemented in a minicomputer system was applied to a real problem. The results strongly correlated with another, independent study.