Applied Biology and Biochemistry

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Applied Biology and Biochemistry

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Browsing Applied Biology and Biochemistry by Subject "alkali"

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    The Efficacy of Alkaline Steeping in Extracting Proanthocyanidins and its effects on Malt quality in some Sorghum varieties
    (Society of Education, 2013-12) Dhlamini, Zephaniah; Banda, L.; Makoni, C.
    Sorghum malt is an important raw material in opaque beer brewing. Use of high tannin sorghum varieties reduces malt quality due to binding of tannins to proteins. Tannins are usually leached from sorghum grain using formalin during the steeping stage of malting. However, formalin has been shown to have potentially harmful health effects thus driving the need to find alternative methods of tannin removal. In this study, the effectiveness of alkalis (calcium and sodium hydroxides) was assessed. The amount of tannins in red (NS5511) and brown (SMILE) malting sorghum varieties were determined by the butanol-HCl assay and compared to other food varieties. The NS5511 and SMILE were steeped in 0.02M and 0.04M concentrations of each of Ca(OH)2, NaOH and formalin for 6hrs, subjected to germination conditions (26°C for 115hours) and kilned off at 60°C for 50hours. The germination rate, as measured by the chit count was determined and the alkali treated samples had the highest germination rates compared to formalin. Furthermore, the alkali treated samples had highest diastatic units. The amount of residual tannins was determined, and formalin treatment leached slightly more tannins than the alkalis. We conclude that alkalis can replace formalin since they are almost equally effective and have less serious health effects.