178 M.V. Moreno-Arribas and M.C. Polo
It was suggested in 1971 that histamine production can be prevented by con-
trolling the microbial flora of wines using inocula from malolactic fermentation
(Smith 1980). Spontaneous malolactic fermentation is still extensively applied in
cellars worldwide, although it is sometimes difficult to control the malolactic fer-
mentations induced. Commercial strains ofO. oenihave been selected for their eno-
logical properties and these must be analyzed to ensure the absence of amino acid
decarboxylase enzymes. In vitro studies carried out in our laboratory studied the
capacity of four commercial malolactic starters to form biogenic amines and found
that none of them produced histamine, tyramine or putrescine (Moreno-Arribas
et al. 2003). It has also been demonstrated that inoculation with commercial starter
cultures that do not contain the genes that encode the enzymes involved in biogenic
amine production, is a real and feasible option to control the generation of biogenic
amines during wine manufacture in industrial conditions (Marcobal et al. 2006a). It
also seems that the co-inoculation of starter cultures ofO. oenisimultaneously to
alcoholic fermentation, can potentially reduce amine formation even more than the
conventional inoculation carried out when alcoholic fermentation has finished.
The effect of complex commercial fermentation activators on biogenic amine
production was tested by Marques et al. (2008). On the whole, it does not seem
that complex nutrient preparations produced for the use with fermentation starter
cultures pose a serious threat to biogenic amine production in wines.
Currently, the most practical way to control the problem of biogenic amine
production is based on inhibiting the growth of indigenous decarboxylase-positive
bacteria and other microorganisms responsible for this alteration. Sulphur diox-
ide (SO 2 ) is the antimicrobial agent traditionally used in cellars after malolactic
fermentation has finished, to remove yeasts and bacteria not wanted in the later
stages. According to some authors, the addition of SO 2 does not affect the formation
of biogenic amines during alcoholic fermentation (Garde-Cerd ́an et al. 2007).
Studies carried out throughout the process of industrial wine production indicate
that addition of SO 2 to red wines, at concentrations known to reduce the bacte-
rial population, prevents the formation of biogenic amines during wine aging and
maturation (Marcobal et al. 2006a). Because of these conclusions, SO 2 is added
immediately after malic acid breakdown toremove the lactic acid bacteria as quickly
as possible so as to prevent biogenic amine formation. On the other hand, in several
studies a rise in histamine after malolactic fermentation has finished and during
wine aging has been observed, indicating that the addition of sulphur dioxide after
malolactic fermentation has finished does not totally detain the enzymatic reactions
carried out by the bacteria, including the decarboxylation of amino acids. Also, the
use of SO 2 is less effective due to the high pH values of many wines and, often,
the concentration of amines can rise in sulfited wines during aging. In fact, several
studies have shown that red wines with high histamine contents (>10 mg/L) are
characterized by pH values above 3.7 (Landete et al. 2005; Marcobal et al. 2006a).
Lysozyme is an enzyme that can cause lysis of the cell walls of Gram-positive
bacteria, including lactic acid bacteria in wine (Delfini 2004). Lysozyme maintains
its activity in wines with high pH values so it can be used successfully to delay or
inhibit the growth of lactic acid bacteria, especially when used together with SO 2.