The Formation of Aldehydes from Amino Acids by Tea Leaves Extracts

In the reaction system containing amino acid, tea leaves extract and (−)-epicatechin, some amino acids such as glycine, alanine, valine, leucine, isoleucine, methionine and phenylalanine produced formaldehyde, acetaldehyde, isobutyraldehyde, isovaleraldehyde, 2-methylbutanal, methional and phenylacetaldehyde, respectively. The production of these aldehydes was regarded to proceed as Strecker degradation. On the production of phenylacetaldehyde it was revealed in the tea leaves extract-phenol-phenylalanine system that: 1) di-phenol was the most effective co-factor in comparison with mono- and tri-phenols; 2) the optimum concentration of (−)-epicatechin was 5×10-4M and the production was depressed at the concentration more than 5×l0-4M; 3) the production decreased by diluting tea leaves extract.