Relationship between Sencha Evaluation in the Competition and its Inorganic Elements

Abstract

We analyzed the inorganic elements of the three grades of green tea (High, Medium, Low) at the Kansai green tea competition in 2015 to clarify the relationship between the sencha evaluation in the competition and the inorganic components. The content of nitrogen was significantly higher in High and Medium grades than that in Low grade. In the trace elements, zinc content was also significantly higher in High and Medium grades than that in Low grade. In addition, the contents of nitrogen and zinc were highly involved in the components of appearance, aroma, liquid color, and taste, which are the evaluation items of the green tea competition. Also, the contents of nitrogen and zinc were considered to be important components for the sencha evaluation by the principal component analysis. A positive correlation (r = 0.793) was observed between the content of nitrogen and zinc for the High- and Low-grade tea leaves. These results suggested that the sencha evaluation might be associated not only with the contents of theanine and nitrogen but also with content of the trace element, zinc in green tea leaves.