Annual Progress Report on Malting Barley Research March, 2002

Residual α-Glucosidase Activity
175
150
125
100
75
50
25
Mutant
Wild Type
154
0
0 10 20 30 40 50 60 70
Temperature (°C)
Figure 1. Effect of temperature on the activities of recombinant wild type (squares) and
mutant (triangles) α-glucosidases at pH 6.0. Enzymes were incubated for 10 minutes at
temperatures ranging from 0 to 60°C at pH 6. The residual rates of maltose hydrolysis
were assayed for 18 hours at 30°C at pH 4.5. Residual activities are based on % of nonheated
controls.
Temperature (°C)
110
100
90
80
70
60
50
40
0 20 40 60 80 100 120 140 160 180 200
*
Time (min)
**
Adjunct Mash
Main Mash
Figure 2. Changes in mash temperature as a function of time. The adjunct mash (open
circles) and main mash (closed circles) are shown. Samples for carbohydrate analysis
were taken after protein rest (*) and after completion of starch conversion as determined
by iodine testing (**).