Abstract

S2-03

The Effectiveness of Processing Techniques in Reducing Total Cyanogens during the Production of some Cassava Foods

Agbor-Egbe T.¹, I. Lape Mbome and S. Tr?che²

1.   Centre for Food and Nutrition Research, P 0 Box 6163, Yaounde, Cameroon    agboregetom@hotmail.com

This study, based on a preliminary survey, was undertaken to investigate the effectiveness of  processing techniques in reducing total cyanogens of a wide range of cassava varieties to low levels during the production of b?ton de manioc, fufu and gari. The processing techniques were highly effective in substantially reducing the mean total cyanogens contents (197.3-951.5 mg HCN equivalent/Kg) of freshly harvested cassava roots to low levels (1.3-11.0 mg HCN/Kg), irrespective of their initial values. Similar mean reduction levels (97.1-99.8%) in total cyanogens for each of the foods studied were obtained by the processors. With regard to the greatest changes in total cyanogen levels, the most important techniques used in the production of the foods studied were those that maximise cassava root tissue disintegration.  Grating and soaking caused marked decreases in both cyanogenic glucosides and pH levels, which coincided with significant increases in cyanohydrins. These changes were more evident during gari production than for b?ton de manioc and fufu. Most of the residual cyanogens were in the form of cyanohydrins and/or hydrogen cyanide, which were partially removed during subsequent processing (steam cooking and garification).