2009_Book_FoodChemistry

15.4 Baked Products 733
Table 15.50. Baking times and temperatures
Baked product Weight Baking time Oven
(g) (min) temperature
( ◦ C)
Buns, rolls and other
small baked products 45 18–20 250–240
Wheat bread
(self-supported dough) a 500 25–30 240–230
Wheat bread (pan-baked) b 500 35–40 240–230
Wheat bread
(self-supported dough) 1000 40–50 240–220
Rye mix bread
(self-supported dough) 1500 55–65 250–200
Rye bread
(self-supported dough) 1500 60–70 260–200
Pumpernickel (pan-baked) 3000 16–14 hrs. 180–100
a Hearth bread.
b Pan bread.
Table 15.51. The effect of baking time and temperature on the quality of rye whole meal bread
Baking time (min) 90 180 270
Baking temperature ( ◦ C) 240–210 210–185 185–160
Bread yield (ml) 142 142 140
Crust strength (mm) 4 5 6
Taste raw, slightly aromatic strongly
aromatic
aromatic
above ca. 60 ◦ C (Fig. 15.47). The membranes
give way and become permeable, allowing CO 2 ,
ethanol, and water vapor to escape. The baking
volume decreases slightly until the denatured
proteins, with swollen and partially gelatinized
starch, form a stable crumb framework, which
contains pores down to 3 µm in diameter. Thinwalled
membranes which can stand a greater
increase in temperature on stretching, without
becoming gas permeable; this is the prerequisite
for a baked product with a large volume and
uniform fine pores. A relatively large amount of
high-molecular glutelins in gluten has a favorable
effect. Dough made from wheat varieties with
poor baking properties becomes gas permeable
at a relatively low temperature and the baking
volume remains correspondingly low. The extent
of starch swelling depends on the available water.
The water in dough is preferentially bound by
prolamins, glutelins and pentosans. Part of this
water becomes available to swell the starch
during baking. Limited starch swelling results
in a brittle crumb, whereas extensive swelling
makes the crumb greasy or gluey.
In contrast to the crumb, the starch granules of
the crust surface gelatinize almost completely.
This is expecially the case when the oven humidity
is high, e. g., when baking occurs below
a steam header. Investigations involving gluten
and starch mixtures to which the emulsifier
stearyl-2-lactylate was added revealed that lipid
transfer occurs from gluten to starch during
heating of the mixture above 50 ◦ C (Table 15.52).
Apparently, the high swelling and gelatinization
of the starch granules, which occurs above 50 ◦ C
(cf. Table 4.20), promotes lipid binding.
The specific volume of white bread is higher than
that of rye bread (Table 15.53). The rye crumb
is stronger and less elastic, suggesting that the
pentosans can not fully compensate for the lack