6/23/2017

1

6/23/2017

2

Cross-section of Barley

large granules 25 m

small granules 5 m

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

6/23/2017

3

Comparison of malt a amylase and b amylase

a amylase

b amylase

1

attack on starch molecules

randomly an endo-enzyme

releases maltose an exo-enzyme

2

glucosidic link attacked

a 1-4

a 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