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15.4 Baked Products 725

participate in Maillard reactions during baking,

providing the more intense aroma.

15.4.2.3 Kneading

The kneading process is characterized by the following

stages: mixing of the ingredients and seasonings;

dough development and dough plastification.

The energy input into dough kneading, the dough

properties and baking volumes are interrelated.

For each dough the baking volume passes through

an optimum which is dependent on kneading energy

input (Fig. 15.40). This optimum shifts towards

lower energy input with a flour of weak

gluten content and towards higher energy input

with flours of strong gluten content; and, as expected,

the position of the optimum can be influenced

by flour improvers. Increased additions,

especially of azodicarbonamide, to the dough result

in a successive drop in kneading energy input

(Fig. 15.40).

As the kneading energy moves away from the optimum,

the dough becomes wetter, it starts to stick

to trough walls and its gasholding ability drops

(cf. 15.4.2.5 and Fig. 15.44, 14 and 56). Dough

development of wheat flours requires close to

double the kneading time of rye flours.

The machines used for kneading are grouped according

to their performance based on kneading

time: fast, intensive, and high power kneaders and

mixers (Table 15.49). However, the groups are

not sharply divided. As the kneading speed increases,

the temperature of the dough rises (Table

15.49). Hence, cooling must be used during

kneading to keep the temperature at 22–30 ◦ Cor,

with high speed mixers, at 26–33 ◦ C. The mixer,

in a true sense, does not knead the dough, but rips

or ruptures it. This could reduce the stability of

the dough to such an extent that it could be baked

only as panbread (in which case the pan walls

support the dough) but not as bread made from

selfsupporting dough.

Table 15.49. Examples for kneading conditions in

white bread dough making

Dough mixer/ Speed Kneading Dough

kneader (rpm) time heat a

(min) ΔT( ◦ C)

Rapid kneader 60–75 20 2

Intensive kneader 120–180 10 5

High power

kneader 450 3–5

Mixer 1440 1 9

Mixer 2900 0.75 14

Fig. 15.40. Bread volume as affected by kneading energy

input (according to Frazier et al., 1979)

a Temperature rise during kneading time.

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