2.6.1. Cereal products

The aroma formed by toasting of wheat bread have been identified as 2-acetyl-1-pyrroline, 2-acetyltetrahydropyridine, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 3-methylbutanal, methional and (E)-2-nonenal (1-4), that are the same as wheat bread crust. In particular, acetylpyrroline has to be considered the key aroma compound of wheat bread crust due to its roasty odour quality.

In the earlier stage of toasting (when the bread isn't yet brown) there are formed several compounds such as 2-acetyl-1-pyrroline, 2-methylbutyric acid and 3-methylbutyric acid. Methional is found in the begin of toasting but decreases concentration when the bread is in latter stages of toasting.

The concentration of other compounds increase during the toasting process (Grosch, et.al,1995 ).

The popcorn taste is due to N-furfuryl-pyrrole and N-fufuryl-2-formyl-pyrrole, who are formed by heating and 2,4-decanienal, 2-furfurylthiol and 4-vinyl-2-methoxyphenol. The aroma of the two aroma formed by eating can be enhanced by enriching the corn with hidroxy proline.