164 M.V. Moreno-Arribas and M.C. Polo
Histamine
PutrescinePhenylethylamin TyramineCadaverineFig. 6A.1Chemical structure of the biogenic amines most frequently found in wines
weight compounds, derived from aromatic or cationic amino acids and all of
them have one or more positive charge and a hydrophobic skeleton. The chemi-
cal structure of biogenic amines can be aliphatic (putrescine, cadaverine, spermine,
spermidine), aromatic (tyramine, phenylethylamine) or heterocyclic (histamine,
tryptamine). Figure 6A.1 shows the chemical structures of some biogenic amines.
They are endogenous of plants but can also be found in fresh fruit and vegetables.
However, amines are mainly formed in foods in fermentative processes and dur-
ing aging and storage, produced by microbial decarboxylation of the corresponding
amino acid precursors, which is why they are referred to as biogenic. The most
studied of these biogenic amines is histamine.
Biogenic amines are essential at low concentrations for normal metabolic and
physiological functions in animals, plants, and microorganisms. However, these
biologically produced amines can have adverse effects at high concentrations and
pose a health risk for sensitive individuals. Biogenic amines are likely to be found
in foods and beverages that contain proteins or free amino acids, in conditions that
favour microbial or biochemical activity (H ́alasz et al. 1994; Silla Santos 1996).
In fermented foods, the non-volatile or biogenic amines (histamine, putrescine,
cadaverine, spermine, spermidine, agmatine, tyramine tryptamine) and phenylethy-
lamine (a volatile amine) are formed mainly by the microbial decarboxylation of
the corresponding amino acids (Ten Brink et al. 1990). Volatile amines are believed
to be formed by the reductive amination or transamination of the corresponding
aldehyde or ketone.
This chapter tackles the most important aspects of amino acid and biogenic amine
formation during wine manufacture and aging. The significance of biogenic amines
to wine quality and safety will also be reported.
6A.2 Amino Acids
Around 20 free amino acids were detected in grape musts, representing on average
28–39% of the total nitrogen, depending onwhether these corresponded to musts
of white or red wine grapes, respectively (Rapp and Versini 1991). The amino acid