176 M.V. Moreno-Arribas and M.C. Polo
in contact with the grape skin. Prolonged maceration after alcoholic fermentation at
low temperatures is another frequently used option to prolong the extraction period.
Commercial pectolytic enzymes are commonly used in winemaking to increase the
extraction of compounds, facilitating the operations of pressing and clarification,
increasing the clarity of musts and wines. In some cases, their addition is expected
to improve the extraction of phenolic compounds and aroma. However, it is known
that these commercial preparations can produce some secondary enzymatic activi-
ties, which are sometimes undesirable in wines. Among other activities, a significant
proteolytic activity has also been mentioned, that would lead to an increase in amino
acid concentration.
In order to gain a thorough understanding of the variables and technologies
implicated in biogenic amine concentration, 55 different batches of red wine were
produced by different technologies used inwine cellars. In addition to studying the
changes in amine concentrations due to the producing cellar or the year of harvest,
the following variables were also considered: the use of pectolytic enzymes, the
type of container used for malolactic fermentation (stainless steel or oak barrel),
inoculation with commercial preparations, permanence of the wine with lees, dura-
tion and intensity of the maceration (Table 6A.1). To study together the effects of
the different technological processes used during winemaking on the concentration
of biogenic amines in the wines studied, a multifactorial analysis of variance was
used (Mart ́ın-Alvarez et al. 2006). Significant differences were found in the levels ́
of biogenic amines in relation to the cellar producing the wine and also the year
of harvest. Moreover, of the winemaking factors and practices studied, the use of
pectolytic enzymes appeared to have no effect on the concentration of wine biogenic
amines. Prolonged permanence of the wine with the lees affects the concentration of
amino acids and favors amine production,while intense and prolonged macerations
produce wines with higher levels of histamine, tyramine, putrescine and cadaver-
ine. On the other hand, with maceration, and especially, extraction of polyphenols
from the grape, these can react with aminoacids giving rise to lower levels of wine
biogenic amines in some cases.
Indirectly, yeasts may play an important role in the subsequent production of
biogenic amines by lactic acid bacteria with decarboxylase activity, altering the
composition of amino acids during alcoholicfermentation. Yeasts may also release
amino acids during autolysis (Moreno-Arribas et al. 1998; Villamiel et al. 2008),
which can act as precursors of biogenic amines during malolactic fermentation and
during wine aging. Yeast autolysis favors the growth and activity of lactic acid
bacteria due to the release of vitamins and large nitrogenated compounds. Lactic
acid bacteria can hydrolyze and metabolize the proteins and peptides and use the
amino acids as nutrients and sources of energy (Manca de Nadra et al. 1997, 1999;
Leitao et al. 2000; Remize et al. 2006; Alcaide-Hidalgo et al. 2008). These amino
acids may include precursors of biogenic amines. Yeast and bacterial lees may
also be sources of bacteria with decarboxylase enzymes, potentially amine pro-
ducers. In fact, the first gene of the enzyme ornithine decarboxylase, in a lactic
acid bacteria of enological origin, was isolated from wine lees (Marcobal et al.
2004).