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United States Department of Agriculture

Agricultural Research Service

Title: Relationships Between Barley and Malt Quality Traits, Enzyme Activities Andthe Production of Fermentable Sugars During Mashing

item Henson, Cynthia
item Karpelenia, Charles - UNIVERSITY OF WISCONSIN

Submitted to: Brewers Digest
Publication Type: Abstract Only
Publication Acceptance Date: March 26, 1998
Publication Date: N/A

Technical Abstract: A malt's ability to convert starch to fermentable sugars is typically assessed by measuring alpha-amylase activity and diastitic power (DP) even though we know that four enzymes may participate in starch conversion. To determine if the measurement of these four different enzyme activities would provide a better assessment of a malt's ability to produce fermentable sugars than the parameters currently tested, we analyzed the individual enzyme activities of malts produced from barleys grown in four locations that participate in uniform nursery trials and determined the concentrations of fermentable sugars produced during mashing for two of these same locations. We then determined the linear correlation coefficients for relationships between concentrations of glucose, maltose and maltotriose in the mashes and measurements of enzyme activities in the malts. Strong location effects were apparent. However, in all cases where diastatic power significantly correlated with glucose and maltotriose in the mashes, the activities of alpha-amylase and alpha-glucosidase were also correlated with glucose and maltotriose. In all locations the activities of alpha-amylase and alpha-glucosidase were highly correlated. No significant and positive correlation was detected between an individual enzyme activity and the concentration of a fermentable sugar that was not also a correlation detected between DP and the same sugar.

Last Modified: 4/22/2015
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