Abstract
To clarify the effect of cooking on 137Cs mass, 10 species and 11 organ samples of edible wild plants were cooked: the spore stem of Equisetum arvense (Ea), petioles and flower buds of Petasites japonicus (Pj), and sprouts of Fallopia japonica (Fj), Aralia cordata (Ac), Parasenecio delphiniifolius (Pd), Senecio cannabifolius (Sc), Pteridium aquilinum (Pa), Osmunda japonica (Oj), Eleutherococcus sciadophylloides (Es), and Aralia elata (Ae). They grew up on the land exposed to the 2011 Fukushima Daiichi Nuclear Power Station accident. Soaking in hot water reduced the 137Cs mass of Fj [137Cs food-processing retention factor or 137Cs Fr = (processed/unprocessed sample 137Cs mass ratio) = 0.14 ± 0.11 (mean ± SD)], and boiling in hot water with salt also reduced the 137Cs masses of Pj, Ac, Pd, Es, and Ae (range 137Cs Fr = 0.41 ± 0.14 to 0.99 ± 0.09). Stringent removal using baking soda reduced the 137Cs masses of Pa (137Cs Fr = 0.089) and Oj (137Cs Fr = 0.32 ± 0.04). Stringent removal using baking soda and drying for long-term preservation markedly reduced the 137Cs mass of Oj (137Cs Fr = 0.009 ± 0.012). Desalting after prolonged salting also markedly reduced the 137Cs masses of Pa, Oj, and Es (range 137Cs Fr = 0.016 ± 0.015 to 0.041 ± 0.012). However, the effect of this recipe on Sc was smaller (137Cs Fr = 0.24 ± 0.15). Preparation by removing the less edible parts before processing the remainder and making tempura had no significant effect on the 137Cs mass. Cooking using baking soda and drying markedly reduced the 137Cs mass, as did desalting after prolonged salting. Both recipes are for long-term preservation.
