Evaluation of the potentials of millet, sorghum and barley with similar nitrogen contents malted at their optimum germination temperatures for use in brewing

摘要

Studies on the malting physiology of barley have led to similar studies on millet and sorghum. This study compares the outcomes of the malting physiology of millet, sorghum and barley. Results show that optimal development of diastatic power, soluble nitrogen, hot water extract and the wide range of amino acids of these three cereals is related to optimal malting conditions and appropriate mashing procedures. Transfer of the nitrogen/extract/soluble nitrogen/diastatic concepts of barley malt do not apply to millet and sorghum. However, all the cereals studied produced the range of amino acids required by yeast for fermentation. Sorghum malt released the highest amounts of group 1 amino acids, usually taken up faster by yeast. It also produced and released the highest amounts of amino acids, classified as group 2, which are assimilated more slowly than group 1 amino acids. It also produced and released more of the amino acids that are slowest to be assimilated during fermentation, as well as very high levels of proline. Optic barley malt produced and released the least amount of proline. The fate of proline during yeast fermentation is not clear, but it is believed that proline is not utilized during fermentation.