The production of aldehydes from amino acids in roasted cocoa
It has been suggested in the literature that aldehydes are produced from the amino acids in roasting cocoa beans by the Strecker degradation. [U-14C]-L-Leucine [U-14C]-L-3-phenylalanine and [U-14C]-L-threonine- were used in an investigation to confirm this mechanism. The labelled amino acids were introduced into ripe cocoa beans which were then fermented, dried and roasted under conditions approaching those of normal practice. The carbonyl compounds were collected as 2,4-dinitrophenylhydrazones and identified by thin-layer chromatography (t.l.c) and autoradiography. The major products from [14C]-L-leucine and [14C]-L-3-phenylalanine were isovaleraldehyde and phenylacetaldehyde respectively, which are the aldehydes expected from a Strecker degradation. Some condensation products and other radioactive carbonyl compounds were also noted. The degradation of threonine appeared to occur early in the roasting process and to be more complex. Acetaldehyde was identified and it is suggested that this was produced via the Strecker aldehyde.
| Main Authors: | , |
|---|---|
| Format: | biblioteca |
| Published: |
1972
|
| Subjects: | CACAO, TOSTADO, AMINOACIDOS, ALDEHIDOS, CROMATOGRAFIA, ANALISIS QUIMICO, FERMENTACION, |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | It has been suggested in the literature that aldehydes are produced from the amino acids in roasting cocoa beans by the Strecker degradation. [U-14C]-L-Leucine [U-14C]-L-3-phenylalanine and [U-14C]-L-threonine- were used in an investigation to confirm this mechanism. The labelled amino acids were introduced into ripe cocoa beans which were then fermented, dried and roasted under conditions approaching those of normal practice. The carbonyl compounds were collected as 2,4-dinitrophenylhydrazones and identified by thin-layer chromatography (t.l.c) and autoradiography. The major products from [14C]-L-leucine and [14C]-L-3-phenylalanine were isovaleraldehyde and phenylacetaldehyde respectively, which are the aldehydes expected from a Strecker degradation. Some condensation products and other radioactive carbonyl compounds were also noted. The degradation of threonine appeared to occur early in the roasting process and to be more complex. Acetaldehyde was identified and it is suggested that this was produced via the Strecker aldehyde. |
|---|