6A Amino Acids and Biogenic Amines 175
6A.3.2.3 Other Wine Microorganisms
The ability of 40 strains of acetic acid bacteria isolated from grape must and wine
to produce biogenic amines was screened in synthetic medium and wine (Landete
et al. 2007b), but no positive results were obtained. No further mention regarding
the formation of biogenic amines by aceticacid bacteria was found in the literature.
When the grape vine is subject to biotic stresses, such as those caused by fungus
Botrytis cinerea, this can lead to a rise in the amine content of the grape berries
(Haj ́os et al. 2000).B. cinereais responsible for the formation of Aszu grapes, which
are characteristic of the famous Tokaj wines from Hungary. Amine concentrations
in Aszu wines were found to be higher in three different cultivars studied when com-
pared to corresponding normal wines from the same varieties. A positive correlation
could be made between the biogenic amine content and the number of butts used for
the Aszu wine (Sass-Kiss et al. 2000).
6A.3.3 Factors Affecting Biogenic Amine Formation During Wine
Production
The levels of biogenic amines produced in wine largely depend on the abundance of
amino acid precursors in the medium, since on the whole, biogenic amines increase
with an increase in amino acids. Amino acid content may be influenced by vinifica-
tion methods, grape variety, geographical region and vintage (Soufleros et al. 1998;
Moreno-Arribas et al. 2000). While some factors increase the concentration of
precursor amino acids, other factors influence the growth and enzyme activity of
microorganisms that can form the biogenic amines.
Some amines, such as putrescine and other polyamines, may already be present
in grape berries (H ́alasz et al. 1994; Bover-Cid et al. 2006). It seems that putrescine
concentration in wine may beinfluenced by the geographical region and grape vari-
ety (Gl `oria et al. 1998; Kiss et al. 2006). Potassium deficiencies in the soil have been
linked to a rise in putrescine content in plants, while water deficiencies do not seem
to influence the content of biogenic amines in grape berries and wines (Bover-Cid
et al. 2006). Biogenic amines are also dependent on grape variety and wine nutrition,
which determine the concentration and composition of precursor amino acids in
grape must and wine (Herbert et al. 2005; Soufleros et al. 2007). Different studies
have reported cultivar-related differences in the contents of biogenic amines (Gl `oria
et al. 1998; Soleas et al. 1999; Soufleros et al. 2007), while the vintage and the
region of production can also affect the free amino acid and amine content in must
and wine (Herbert et al. 2005; Mart ́ın-Alvarez et al. 2006). ́
During alcoholic fermentation, the degree of maceration is the first factor that
affects the extraction of some compounds present in the grape skin, especially phe-
nolic compounds, which are responsible for the color of the wine. However, not only
does the maceration affect the extraction of polyphenols but also of other grape
components, such as proteins, polysaccharides and, also, amino acids, which are
precursors of biogenic amines. In most red wines, alcoholic fermentation takes place