Abstract:

The traditional malting technology was modified by inoculation of the soaking solution with a
Geotrichum candidum strain isolated from Gansu NO.3 beer barley. The effect of inoculum size, soaking
temperature and soaking solution pH malt quality was investigated by measuring malt saccharification capacity
and the contents of α-amino nitrogen (α-AN) and extracts. The results showed that under the optimized malting
conditions: inoculums size of 104 CFU/g barley, 15 ℃ and pH 4.0, the predicted score for comprehensive evaluation
of malt quality was 205.33, while the actual score was 206.15. In addition, the observed saccharification capacity
and α-AN and extract contents were 308.5 WK, 186 mg/100 g and 87.1%, respectively, all of which exceeded those
described in the light industry standard QB/T 1686—2008 for select products.

Key words: barley；Geotrichum candidum；diastatic power；&alpha, -amino nitrogen (&alpha, -AN)；extracts；response surface methodology；optimization