Trace Elements in Tea Leaves from Yakushima and their Regional Variations

Abstract

In this study, we investigated whether there were any regional or inter-variety differences in trace element contents between tea leaves grown in the isolated island of Yakushima and those grown in Shizuoka and Kyushu, and whether the trace element contents are effective in distinguishing the leaves produced in different regions within a small area.

The trace element contents in 32, 14, and 7 samples of tea leaves produced in Yakushima, Shizuoka, and Kyushu, respectively, were measured using an ICPS1000IV.

The scatter plot from discriminant analysis of varieties showed that each variety formed a cluster, but no differences in the trace element content were observed. The scatter plot from discriminant analysis of the samples from Yakushima, Shizuoka, and Kyushu showed that the samples from each region formed a distinct cluster, and it was possible to identify the origin based on the trace element content. No regional differences were found in the trace element content when analysis involved the samples collected in Yakushima only. However, when cultivated regions were categorized into two areas, the Yakushima samples were found to form two groups based on the Mg and Mn contents, those from northeast and southeast areas.