Microbiological study of sorghum during malting showed that damaged grains caused microbial infection during malting of sorghum. Lack of adequate handling and screening facilities caused damaged grains to develop microbial infection which spread to undamaged grains. This results in unacceptable levels of microbial infection of malted samples of sorghum. Abrasion study, where the pericarp of sorghum grains were damaged to allow the penetration of formaldehyde solution to destroy micro-organisms in the sub-surface layer of sorghum further confirmed that potential infection of "sound" grains resided mainly at the surface of the pericarp. Application of formaldehyde solution during steeping was effective in controlling microbial activities present on the surface of sorghum grains. A concentration of 0.1% formaldehyde solution, applied during the first steep was more effective than a concentration of 0.05% formaldehyde in controlling microbial infection during malting of sorghum. Application of similar concentration (0.1%) formaldehyde solution during the last (second) steep, was not only the most effective treatment in limiting microbial infection during germination of sorghum, it also increased the levels of hydrolytic enzymes which develop in sorghum during malting. The concentration of formaldehyde solution (0.1%) used in this study can be used to control microbial infection in sorghum, especially when applied to the final steep.
|Number of pages||6|
|Journal||Journal of the Institute of Brewing|
|Publication status||Published - 1999|