Influence of the technological know-how of producers on the biochemical characteristics of red sorghum malt from small scale production units in Ouagadougou (Burkina Faso)

Abstract

The process of red sorghum malt production was monitored three times in five production units (PU) selected upon their ability to produce malt flours having a high capacity to fluidify high-energy-density gruels. Raw, germinated and degermed seeds were analysed for macronutrient, soluble sugars, phytate and cyanide contents and α-amylase activity. Know-how differences between producers lay mainly in the duration and type of equipment used for steeping and germination. Moreover, three PUs applied a maturation step before sun-drying and one PU added ashes to steeped seeds before germination. No significant difference was detected in the proximate composition of malts from the five PUs. For all PUs, traditional malting increased the protein content and decreased the lipid and ash contents, while the fibre content was not affected. Significant increases in sugar contents and in α-amylase activity were observed but in variable proportions from one PU to another. The phytate content decreased significantly in all PUs. The cyanide content increased in all PUs but more drastically or less drastically according to the PU. Finally, degerming lowered the cyanide content to an acceptable level for human consumption. The between-PU variability may be due either to the nature and origin of the raw seeds or to technological know-how differences between producers. Further investigations are needed to optimize and standardize the malting process with a view to maximizing α-amylase and phytase activities and minimizing the variability of their biochemical characteristics.