The quantitative cyanide liberation resulting from hydrolysis of the cyanogenic glycosides of some edible tropical cyanophoric plants by a P-glucosidase enzyme prepared from African giant snail (Achatina achatina) was studied spectrophotometrically. The results were compared with that obtained with cassava linamarase that has relatively the same unit of activity. The quantitative yield of HCN equivalent from fresh cassava root pulp following incubation with A. achatina beta-glucosidase (4.7 units ml(-1)) was 1.65-14.46 mg CN(-)100 g(-1) fresh weight (for 10 different cassava cultivars) and 1.67-14.17 mg CN- 100 g(-1) fresh weight when incubated with cassava linamarase (5.0 units ml(-1)) under the same assay conditions. There was no statistically significant differences (P > 0.01) between the hydrolytic activities of these two beta-glucosidases towards the cyanogenic glycosides of cassava, lima beans, wheat and standard linamarin. These results strongly indicate that A. achatina is another good source of P-glycosidase with high hydrolytic activity towards cyanogenic glycosides of some plants including cassava. (c) 2004 Elsevier Ltd. All rights reserved.