The effects of different cooking modes on the 137Cs, 40K, and total K content in Boletus edulis (King Bolete) mushrooms

This study aimed to get an insight into the effects of household processing on the leaching behaviour of 137Cs and 40K from fresh, frozen and dried Boletus edulis (King Bolete) mushrooms. Three processes were investigated—blanching, blanching and pickling, and drying followed by grinding and soaking. The activity concentrations of 137Cs and 40K in the fresh unprocessed mushrooms were 270 Bq kg−1 dry biomass (27 Bq kg−1 whole weight) and 590 Bq kg−1 db (59 Bq kg−1 ww), respectively. Blanching of fresh mushrooms decreased 137Cs activity by 55%, and 40K activity by 34%, and blanching of deep-frozen mushrooms caused a reduction of 52% and 44% (db) (equivalent to whole weight reductions of 37% and 8.5%, and 67% and 22%, respectively). Blanching and pickling of fresh mushrooms decreased 137Cs activity by 83% and 40K activity by 87%, while blanching deep-frozen mushrooms resulted in decreases of 88% and 80% (db) (whole weight decreases of 77% and 81%, and by ~ 84% and 72%, respectively). This study confirms earlier reports that blanching of fresh or frozen mushrooms alone is not as efficient at removing 137Cs as blanching followed by pickling. The study also shows that the initial rate of fruiting body disintegration and pre-preparation (comparing fresh, deep-frozen, or dried and ground) can have an impact on the leaching rate of the water soluble fraction of metallic elements.