2009_Book_FoodChemistry

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 to Gassenmeier and Schieberle, 1995): flour (59 g), water (50 g) and yeast (0.25 g) were incubated
at 30 ◦ C
Fig. 15.50. Formation of 2-
acetyl-1-pyrroline (•–•) and
2-acetyltetrahydropyridine
(◦–◦) on toasting white bread
(according to Rychlik and
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, phenylacetaldehyde,
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-Furfurylthiol
also contributes only to the aroma of the rye
bread crust.