PowerPoint Presentation of malt αamylase and βamylase αamylase βamylase 1 attack on starch molecules randomly an endo-enzyme releases maltose an exo-enzyme

Cross-section of Barley

large granules 25 µ small granules 5 µ

by # % 13 87

by wt % 89 11

protein % 2 1.5

gel temp C 61 92

amylose % 24 40.5

amylopectin% 74 58

Barley starch granules

Comparison of malt α amylase and β amylase

α amylase β amylase

1 attack on starch molecules randomly an endo-enzyme releases maltose an exo-enzyme

2 glucosidic link attacked α 1-4 α 1-4

3 # of reducing groups produced one one

4 optimum pH 5.5 5.2

5 optimum temperature 70 C 60 C

6 presence during malting not present in barley present but inactive in barley