Avaliação do efeito de quatro métodos de processamento de mandioca, na redução de cianogenos, praticados em Nampula

Abstract

In 1981, in Nampula Province, a large epidemic of Konzo was described, a neurological disease characterized by paralysis of both legs, whose etiology was associated with the consumption of unprocessed bitter cassava, combined with a diet low in protein. In subsequent years, due to drought and war, these episodes continued to be registered in the Districts of Mogincual, Memba, Murrupula, Namapa and Mogovolas, totaling 1665 cases until 1993. Due to this situation, it became imperative to know the varieties of bitter cassava grown in the areas affected by the epidemic, the homemade methods of processing bitter cassava and studying the physicochemical characteristics of the flours obtained by such methods. Four methods of processing bitter cassava roots were chosen for the study as they were commonly used by the population in the study areas. These methods are namely: drying roots in the sun for 9 hours; drying of roots in the sun for 3-5 days; drying of roots in the sun for 8-15 days and fermentation of roots by heap, followed by drying in the sun for 8-15 days. In semi-structured interviews with housewives, 9 varieties of bitter cassava were mentioned, with Gurúè, Tomo and Makela being the most common, whose cyanogenic potential in the pulp of fresh roots was between 132.62 ± 45.80 - 401.12 ± 288.69 milligrams equivalent. of cyanide per kilogram of dry weight (mg CN eq/kg ps). The laboratory analysis of flours processed by the four most common methods resulted in total cyanide levels between 9.63 ± 10.85 - 53.73 ± 36.63 mg CN eq/kg ps. The flours whose cyanide content is within the FAO/WHO Standards (10 mg CN eq/kg ps), resulted from the heap fermentation method, in which the roots used were whole or large pieces.