Radiocaesium concentration of the first crop of processed tea and it's extracts, and the second crop of processed tea manufactured in Kanagawa Prefecture in 2012

We conducted this study to understand the relation of 137Cs concentration of the first crop of processed tea and that of its extracts manufactured in Kanagawa Prefecture in 2012. In the case of the first crop, processed tea was brewed in 30 times its volume in hot water (at 90℃) for 1 minute, the 137Cs concentration of processed tea extracts was diluted to 1/68.9 that of processed tea on average and extraction efficiency of 137Cs from processed tea was 46.2% on average. The correlation coefficient between 137Cs concentration of the first crop of processed tea and that of extracts was 0.799(p<0.01). Furthermore, the relation of 137Cs concentration of the first and second crops of processed tea was analyzed. The 137Cs concentration of the second crop of processed tea was 0.69 compared with that of the first crop of processed tea on average. The correlation coefficient between 137Cs concentration of the first and second crop of processed tea was 0.803(p<0.01). (author)