1981 Volume 28 Issue 3 Pages 119-124
The manufacturing process of innoxious "Ann" from beans (Butter bean, Phaseolus lunatus Linn) containing cyanogenic compounds was studied. The "Ann" used for the analyses was manufactured in a modern and an old factories and the amount of liberated hydrogen cyanide (HCN) in each process was estimated. Liberated HCN in the usual product of "Ann" was not detected by the picric test according to the method of "the Food Hygienic Law" in Japan, but the high amount of HCN was sometimes detected in the "Ann" produced under the conditions which the boiling or the "Shibukiri" process was imperfect. A part of HCN liberated from beans moved to the waste water, and its amount increased with increasing the temperature of soaking water of the beans. Liberation ratio of HCN in the soaking process was 30.2% in the modern factory and 21.3% in the old factory. ("Ann" ("Nama Ann") is a mashed and granulated product of boiled beans. "Shibukiri" is to remove the lye from beans by boiling.)
