Submitted to: American Society of Brewing Chemists Newsletter
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2005
Publication Date: 6/11/2005
Citation: Henson, C.A., Duke, S.H., Karpelenia, C.B. 2005. Osmolyte concentration as an indicator of malt quality. American Society of Brewing Chemists Newsletter. 65(2):25.
Technical Abstract: This study was conducted to test the hypothesis that malt osmolyte concentrations can be used as an indicator of barley malt quality. Seeds of four 6-row and four 2-row genotypes were steeped for six days at 20 C for 6 days. At intervals of 24 h over the steeping regime green malt from each cultivar was removed and tested for osmolyte concentration, malt extract(ME), diastatic power (DP), alpha-amylase activity, soluble/total protein (S/T), and beta-glucan concentration. Osmolyte concentrations increased most rapidly in days 1 through 3 of germination. After 4 days osmolyte concentrations began to plateau. Significant positive correlations were found for malt extract and osmolyte concentrations in days 1 through 4 and day 6 (r=0.740 to 0.942, p=<0.0001). Days 2 and 3 osmolyte concentrations correlated well with ME for all days (r=0.740 t0 0.942, and alpha-amylase activity for days 2 and 3. Day 2 osmolyte concentration correlated well with days 2 through 6 for beta-glucan concentration. No significant correlations were found for DP and osmolyte concentrations on any day. These data indicate that osmolyte concentrations at early time points in steeping are good indicators of several measures of malt quality at later time points in steeping.