Investigation of extraction rate of radioactive cesium from barley to barley tea

Abstract

Barley grown in test fields and harvested in June 2011 was roasted and brewed. The translocation of radioactive cesium from roasted barley to tea was examined at various brewing times. Roasted barley was boiled for 5 min at a ratio of 1.5 L water: 50 g grain, and allowed to brew for 5, 60 and 120 minutes. The concentration of radioactive cesium (134Cs and 137Cs) in the barley tea and residual grain were determined by gamma-ray spectrometry with Gesemiconductor detector. The translocation of radioactive cesium from roasted barley (138 Bq/kg) to tea extract was about 38% at 120 minute extraction and the radioactive cesium concentration of the barley tea was 1.83 Bq/kg. Thus, it was confirmed that even when 100 Bq/kg barley was used as an ingredient, the radioactive cesium concentration of barley tea made with the standard formula was much lower than 10 Bq/kg, the standard limit for water and drinks.