738 15 Cereals and Cereal Products
Fig. 15.49.Time curves of the formation of 2-phenylethanol (•–•) and 3-methylbutanol (◦–◦) in a prefermented
dough (according toGassenmeierandSchieberle, 1995): flour (59 g), water (50 g) and yeast (0.25 g) were incu-
bated at 30◦C
Fig. 15.50.Formation of 2-
acetyl-1-pyrroline (•–•)and
2-acetyltetrahydropyridine
(◦–◦) on toasting white bread
(according toRychlikand
Grosch). Abscissa: intensity
of browning (8: very strong).
crust with high FD values: methional, 2-/3-
methylbutanal, 4-hydroxy-2,5-dimethyl-3(2H)-
furanone (HD3F), 2-furfurylthiol, (Z)-4-heptenal,
1-octen-3-one, (Z)-1,5-octadien-3-one, pheny-
lacetaldehyde, 2,3-diethyl-5-methylpyrazine and
(E)-β-damascenone. The difference in the crust
aroma of white and rye bread is due to the fact
that the rye bread crust contains much more
3-methylbutanal, methional and HD3F but less
2-acetyl-1-pyrroline (Table 15.62). 2-Furfuryl-
thiol also contributes only to the aroma of the rye
bread crust.