Whole grain brewing and malting potential of 17 sorghum varieties

Abstract

The malting potential of 17 sorghum varieties namely: Kazea Manga, Kapeli, Kemolga, Global 2000, Belko, Keriga, Mankaraga, Kapaala, Kadaga, Bumbago, Yakpaji, Kasheagu, Zelle, Nakpaji, Sarsorg E5 - 2, Sarsorg M13 - 3 and Sarsorg M1 - 1 were investigated. These land races of sorghum in Ghana are known to do very well on the field, and are also believed to have similar brewing properties to well known varieties like Kapaala. Their physical and chemical qualities and germination capacities were determined. Other key quality parameters, such as the level of malt ἀ-amylase and β-Amylase activities were also assessed. The assay format is shown in Appendices 1 & 2). The study revealed that moisture content of all varieties was below 10%. All the varieties were mostly whole grains and matured. Weevil damaged kernels were not detected in any of the seventeen samples. Sarsorg M1, Kasheagu, Sarsorm M 13-3, Mankaraga and Kemolga had unsatisfactory germination capacities. The germination capacity was highest for Kazea Manga and lowest for Mankaraga. A fat level of less than 4% which is within operational range was found in most of the samples except Zelle and Global 2000. Average carbohydrate content of the grains was 75.2% with a standard deviation of ±2.3. For Beta-amylase activity, Kazea Manga had the highest activity (61.6 µg) followed by Kemolga (53.7 µg) and Bumbago (52.4). The activities of Sarsorg E5 - 2 (8.6 µg) and Kadaga (14.0) were very low. The high values of germination and ἀ-amylase activities of Kazea Manga and Nakpaji varieties indicate that the two varieties are comparable to Kapaala in terms of malting properties. However, it is recommended these two go through further analysis to ascertain their mashing and brewing potentials