Hostname: page-component-848d4c4894-ndmmz Total loading time: 0 Render date: 2024-05-15T02:45:53.671Z Has data issue: false hasContentIssue false
  • English
  • Français

Estimation of Hydrogen Cyanide Released from Cassava by Organic Solvents

Published online by Cambridge University Press:  03 October 2008

Hugh J. Williams
Hugh J. Williams
Affiliation:
Njala University College, University of Sierra Leone, PMB, Freetown, Sierra Leone
Get access Rights & Permissions [Opens in a new window]

Summary

Methods are described for releasing HCN from cassava leaves and tubers by organic solvents and its spectrophotometric estimation as the red complex formed with alkaline picrate. Chloroform was the most efficient solvent, with toluene an acceptable alternative, using enough solvent to wet samples thoroughly to maximize cyanide yield. Cyanide content was concentrated in the veins and towards the base of leaves and declined linearly with leaf age. Release of HCN with solvent compared favourably with traditional homogenization/steam distillation with leaves and parenchymal tissue, but was unsatisfactory for tuber peel. The effective removal of HCN from cooked cassava leaves depends chiefly on release of enzymes by efficiently chopping them before boiling, which only slowly destroyed potential cyanide content of unchopped leaves.

Type
Research Article
Information
Experimental Agriculture , Volume 15 , Issue 4 , October 1979 , pp. 393 - 400
Copyright
Copyright © Cambridge University Press 1979

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Bruijn, G. H. de (1971). Etude du Caractere Cyanogenetique du Manioc. Wageningen, Holland: Veenman Zonen.Google Scholar
Conn, E. E. (1969). J. Agric. Fd. Chem. 17, 519.CrossRefGoogle Scholar
Cooke, R. D. (1978). J. Sci. Fd. Agric. 29, 345.CrossRefGoogle Scholar
Cooke, R. D., Howland, A. K. & Hahn, S. K. (1978). Expl Agric. 14, 367.CrossRefGoogle Scholar
Coursey, D. G. (1973). In Chronic Cassava Toxicity. IDRC, Ottawa, Canada, p. 29.Google Scholar
Gilchrist, D. G., Lueschen, W. E. & Hittle, C. N. (1967). Crop Science 7, 267.CrossRefGoogle Scholar
Mirande, M. (1909). Compt. Rend. Acad. Sci. 149, 140.Google Scholar
Nartey, F. (1973). Compt. Rend. Acad. Sci., p. 73.Google Scholar
Nestel, B. L. & MacIntyre, R. (1973). Chronic Cassava Toxicity. IDRC, Ottawa, Canada.Google Scholar
Nowosad, F. S. & MacVicar, R. M. (1940). Sci Agr. 20, 566.Google Scholar
Sadik, S.Okerere, O. U. & Hahn, S. K. (1974). Screening for Cyanogenesis in Cassava. Tech. Bull. 4, IITA, Ibadan, Nigeria.Google Scholar
Williams, H. J. & Edwards, T. G. (1979). Estimation of Cyanide with Alkaline Picrate. Njala University College, Sierra Leone.Google Scholar
Wood, T. (1965). J. Sci. Fd Agric. 16, 300.CrossRefGoogle Scholar
Zitnak, A. (1973). In Chronic Cassava Toxicity. IDRC, Ottawa, Canada, p. 89.Google Scholar