Chemistry Reference
In-Depth Information
700
500
Fungal amylase
Bacterial amylase
Maltogenic amylase
β
-amylase
300
100
1
3
5
7
9
Days
(a)
70
67
64
Maltogenic amylase
Fungal amylase
β
61
-amylase
Bacterial amylase
58
55
52
1
3
5
7
9
Days
(b)
Fig. 6.6
(a) Effect of various starch degrading enzymes on crumb softness as a function of time. (b) Effect
of various starch degrading enzymes on crumb elasticity (springiness or resilience).
enzymes exhibit residual enzymatic activity after baking, which can lead to excessive starch
degradation, causing a collapse of the bread upon storage after baking. Only at very low dose
rates, bacterial amylases can safely be used, but the risk of overdosing remains significant.
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Maltogenic amylase (glucans, 1,4-
α
-maltohydrolase,
EC 3.2.1.33
) produces maltose (and
-configuration. The enzyme is most active between 60
◦
C
and 70
◦
C and is able to degrade amylopectin to a greater extent than fungal amylases or
β
some longer maltodextrines) in the
α
-amylase.
In the above graph (Fig. 6.6(a)), the effects of several different amylases on crumb
freshness are shown.
72
