Environmental Contamination from Industrial Bitter Cassava: Implications for Moisture-Pressure Combination Treatments

  •  Mark Harris    


Commercial processing of cassava produces vast quantities of cyanide-laced waste which can adversely infiltrate water supplies and air breathed by factory workers. This study aimed to determine the comparative concentration of cyanogens in the cassava peel as opposed to that of the pith and the effect of the moisture-pressure combination treatments on cyanide concentration. A semi-quantitiative test using the picrate-spectrophotometer method was applied, where, at room temperature in a closed vial, reactions caused liberation of HCN which reacts with a picrate paper. The results showed a 25% higher level of cyanogen concentration in casssava peels compared to that of blended peels and pith. Treatments released cyanide from samples in the order: 2 h wetting at 50 °C + pressing > 4 h wetting at 25 °C + pressing = 2 h wetting at 40 °C + pressing > 2 h wet at 25 °C + pressing = 4h wet at 25 °C > 12 h pressing. In this manner, wetting for 2 h at 50 °C followed by pressure for 12 h released cyanide by at least 20% more than that of any other treatment. The combination of moisture and pressure enhanced the contact time between linamarin and linamarase to increase the release of HCN. Physiological cyanide overload in organisms from cassava processing occurs in water, land, and air. Therefore the reduction in concentration observed in this study, if applied at an early stage of the cassava processing, should reduce the rate of morbidity in environments at risk.

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