Assessment of cyanogenic glucoside (cyanide) residues in Mbege: an opaque traditional Tanzanian beer

Abstract

Levels of cyanide in two varieties of malted millet, spent grain (Machicha) and opaque beer (Mbege) were determined. Protein content and amino acid composition of the malt, Mbege and Machicha were determined. Mbege was made in the laboratory using an improved method. The cyanide content of millet, malt, spent grain and Mbege were 40.6, 513.4, 18.9 and 8.1 ppm, respectively for the Moshi local millet variety. For Sumbawanga-2 millet variety the cyanide content was found to be 41.2, 489.2, 17.8 and 6.8 ppm for the millet, malt, spent grain and Mbege, respectively. The cyanide content increased linearly as the number of days of germination of the millet grain increased and the highest values of cyanide were attained on the third day of germination. Cyanogenic glucosides in the millet were enzymetically hydrolysed to respective cyanohydrins and volatile hydrogen cyanide due to low pH level of the Mbege which was 4. Malting of the millet increased the protein content by 5%. Lysine, the most limiting amino acid in millet, increased by 20%. It was concluded that the fermentation process of the millet malt into Mbege is efficient in reducing the levels of cyanogenic glucosides below levels considered toxic and therefore rendering the product safe.

Estimating Alcohol Content of Traditional Brew in Western Kenya Using Culturally Relevant Methods: The Case for Cost Over Volume

“…In other parts of western Kenya, busaa is made from sorghum and chang’aa is made from bananas. Not only does brew type vary within Kenya, but it varies across other African countries including Tanzania, Uganda, and Nigeria, where brew is made from bananas, bamboo, coconut, millet, rice, sorghum, and maize (Mosha et al 1996; Ojiji et al 1993; Shayo et al 1998; World Health Organization 2004). Furthermore, Kenyan residents have told us that reporting brew consumed by amount of money spent is common in other parts of the country as well.…”

Effect of germination and autoclaving of sprouted finger millet and kidney beans on cyanide content

“…Relatively, the content of hydrogen cyanide in the un-germinated samples were quite low ranging between 11.7 to 14.7 ppm as opposed to that of germinated samples 2 days at 23 o C, which was quite high ranging from 141.3 to 163.4 ppm. Surprisingly, Shayo et al (1998) found cyanide content of 513.4 and 489.2 ppm in finger millet malt from Moshi and Sumbawanga varieties. Regarding the kidney beans, similar results were found by Adeparusi (2001) who reported significant reduction on levels of cyanide in Lima beans (Phaseolus lunatus) after soaking autoclaving and toasting.…”

“…Steeping of grains (cereals and legumes) in water followed by germination or sprouting is a common household practice in developing countries including Tanzania (Shayo et al, 1998). Germination reduces the high viscosity and water-binding characteristic of starch based porridges.…”

Evaluation of nutritive value and functional qualities of sorghum subjected to different traditional processing methods

“…From Figure 2, it can be seen that animals fed GT showed the highest and most continuous increase in weight over the experimental period. Some of the limiting amino acids such as lysine in cereals (Shayo et al, 1998) are known to be synthesised during germination. Generally, for the two varieties, rats fed germinated feeds performed best.…”