Amino acids malolactic fermentation

Together with proteins and peptides, amino acids constitute the main components of the nitrogenous fraction of musts and wines. They are also the most studied and best known nitrogenated components in wines. Free amino acids in musts are of paramount importance. They constitute a source of nitrogen for yeasts in alcoholic fermentation, for lactic acid bacteria in malolactic fermentation, and can also be a source of aromatic compounds (Kosir and Kidric, 2001). In certain cases, some amino acids... 

Of all the metabolic activities that lactic acid bacteria can carry out in wine, the most important, or desirable, in winemaking is the breakdown of malic acid, but only when it is intended for this to be removed completely from the wine by malolactic fermentation. Although the breakdown of malic and citric acids has considerable consequences from a winemaking perspective, it is also evident that lactic acid bacteria metabolise other wine substrates to ensure their multiplication, including sugars, tartaric acid, glycerine and also some amino acids. We will now describe some of the metabolic transformations that have received most attention in the literature, or which have important repercussions in winemaking. 

Pozo-Bayon, M.A., Alegrfa E.G., Polo, M.C., Tenorio, C., Martin-Alvarez, P.J., Calvo de la Banda, M.T., Ruiz-Larrrea, R, Moreno-Arribas, M.V. (2005). Wine volatile and amino acid com-posidon after malolactic fermentation Effect of Oenococcus oeni and Lactobacillus plantarum starter cultures. J. Agric. Food Chem., 53, 8729-8735. 

A.2.2 Evolution of Free Amino Acids During Malolactic Fermentation. 166... 

On the other hand, other studies focused on O. oeni amino acid requirements for growth and malolactic fermentation in several growth media (Tracey and Britz 1989). Remize et al. (2006) determined the essential amino acids for the growth of five different strains of Oenococcus oeni. These amino acids corresponded to glutamic acid, methionine, phenylalanine, serine and tyrosine for all the strains studied. They also found that the amino acids valine, leucine, tryptophan, isoleucine, histidine and arginine were essential or necessary for the strains studied, but that the amino acids alanine, glycine and proline were not essential. 

Commercial 0. oeni strains are selected for their oenological parameters, including the absence of amino acid decarboxylases. According to the in vitro studies done by Moreno-Arribas et al. (2003), none of the four commercial malolactic starter cultures tested could produce histamine, tyramine or putrescine. Martln-Alvarez et al. (2006) also compared inoculation with spontaneous malolactic fermentation in 224 samples of Spanish red wine. They found that inoculation with a commercial starter culture of lactic acid bacteria could reduce the incidence of biogenic amines compared to spontaneous malolactic fermentation in wines. Starter cultures could eliminate indigenous bacteria, or could possibly degrade the biogenic amines produced by the undesirable strains. 

Soufleros et al. (1998) noted that biogenic amines are formed from their precursor amino acid during and after spontaneous malolactic fermentation. Spoilage bacteria such as Pediococcus 3.nd Lactobacillus hud been implicated (Delfini, 1989 Moreno-Arribas et al., 2000 2003 Arena and Manca de Nadra, 2001), however, yeast strain used for alcoholic... 

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