An investigation into factors influencing beta-amyiase activity in sorghum malt confirmed that ungerminated sorghum grain exhibited essentially no beta-amyiase activity. Malted sorghum had beta-amyiase activity less than 25% of the level in barley malt. Neither reducing agents nor papain affected betaamyiase activity in sorghum, indicating that the enzyme is not in a bound form, unlike in barley. Isoeiectric focusing indicated that sorghum beta-amyiase comprises just one major and one minor isozyme of pi approximately 4.4-4.5, unlike the many isozymes all of higher pi in barley. However, like barley, sorghum beta-amyiase was more temperature-labile than its alpha-amylase. Beta-amyiase activity in sorghum malt was increased by germination time, high germination moisture and over the germination temperature range investigated (24-32°C), 24°C gave the highest activity. The beta-amyiase activity of sorghum malts was significantly correlated with malt diastatic power, despite the fact that alpha-amylase and not beta-amyiase is the predominant diastatic enzyme in sorghum malt.

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