Study on content of cyanide in basidiomycetes and the effect of cooking

The present study was carried out to examine the content of cyanide in basi diomycetes on the market and those in their natural habitat, and to investi gate the chemical form of cyanide in basidiomycetes and the effect of cooki ng. The chemical form of cyanide in basidiomycetes was suggested to be free, be cause there was no significant difference in the quantities of cyanide foun d upon distillation of basidiomycetes immediately and after incubation with two kinds of beta-glucosidase for 16 hours. The content of cyanide was exa mined in a total of 85 samples of 54 kinds of basidiomycetes on the market and those in their natural habitat, and cyanide was detected in 44 samples of 18 kinds. The content of cyanide in basidiomycetes on the market was the highest in Tricholoma giganteum at the level of 86 similar to 283 mu g/g ( n = 11), and was high in Grifola frondosa at 1.8 similar to 46 mu g/g (n = 6), and in Pleurotus eryngii at 1.1 similar to 26 mu g/g (n = 7). The conte nts in sample in the natural habitat were less than 1.0 mu g/g. The remaini ng percentage of the cyanide in T. giganteum after grilling for 6 minutes w as 65%, while that after boiling for 3 minutes was 46% (27% in basidiomycet es and 19% in broth). The level of residual cyanide in T. giganteum after cooking might be suffic ient to cause poisoning with symptoms such as vomiting.