Large-Scale Screening of Cyanogenic Potential in Cassava Roots Using the Enzyme-Based Dipsticks

Abstract

A protocol was developed to use the enzyme-based dipsticks for large scale screening of cyanogenic potential in cassava roots. It involved direct analysis of root tissue slices. Cyanogenic potential (expressed as mg HCN/kg root fresh weight) of 40 cassava varieties were determined. They ranged from about 2 to 590 mg HCN/kg root. Twenty-seven varieties gave values that were comparable to those of control (using root extract). Some varieties were underestimated. For these varieties, values similar to control were obtainable by simply crushing the root slices. Determination of cyanogenic potential based on five roots per variety compared well with those using composite root extracts prepared from three roots (r= 0.81). Semiquantitative estimation of cyanogenic potential for 122 cassava varieties was also carried out by comparing the color of picrate paper against those of known standards; results showed a strong correlation with spectrophotometric method (r= 0.79). © 1998 Academic Press.