Skip to main content
ARS Home » Midwest Area » Madison, Wisconsin » Cereal Crops Research » Research » Publications at this Location » Publication #104657
Title: THE EFFECT OF VARYING MALTING CONDITIONS ON MALT PROTEOLYTIC ENZYMES

Author
item BOLIN, PAUL - NORTH DAKOTA STATE UNIV
item SCHWARTZ, PAUL - NORTH DAKOTA STATE UNIV
item Jones, Berne
item HORSLEY, RICHARD - NORTH DAKOTA STATE UNIV

Submitted to: Barley Newsletter
Publication Type: Abstract Only
Publication Acceptance Date: 7/10/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The soluble proteins (SP) released during the malting of barley effects many aspects of brewing and beer quality. The effects of SP on beer quality are variable, both positive and negative. A long-term goal is to reduce the levels of SP in malt and stabilize concentrations among malt pieces. The objective of this research was to determine the effect of variety (Stander and Robust), location of growth (Hettinger, Williston and Dickinson, ND), growth year (1996 and 1997), steep moisture content (42%, 45% and 48%), green malt germination temperature (15 and 18 degree) and germination time (0, 2, 3 and 5 days) on protease activity. Protease activity was measured directly in malted samples using an in solution protease activity assay. The experiment was arranged as a randomized complete block design, 3 replications, and results statistically analyzed using SAS procedures. A significant increase in protease activity was observed with increasing germination time and germination temperature. Significant 2-way interactions were observed on protease activity: 1) between variety and germination time and; 2) between germination time and germination temperature. A delay in the onset of proteolytic activity by a specific group of protease enzymes was found by: 1) decreasing the germination temperature and; 2) in Robust compared to Sander. Lowering germination temperature and shortening germination time can reduce protease activity. Reduced protease activity would lead to lower SP and higher quality malt.