Wine production is a complex biochemical process that brings into play different microorganisms. Among these, lactic acid bacteria (LAB) play a central role in the quality of the final wine. LAB are not only responsible for the malolactic fermentation that usually occurs after the alcoholic fermentation but also contribute for other important biochemical reactions such as esterase and glycosidase activities and citric acid and methionine metabolism. Nonetheless, LAB may also contribute negatively to wine quality by contributing to the production of volatile phenols, biogenic amines, and ethyl carbamate. This chapter aims to integrate the current knowledge about the role of LAB in wine flavor and quality.Keywords: lactic acid bacteria, winemaking, wine flavor, wine quality, wine safety should be highlighted that some LAB species in particular homofermentative pediococci and heterofermentative lactobacilli are responsible for wine spoilage [1].LAB metabolic activity that may have a very significant impact on wine flavor includes the metabolism of citric acid and amino acids, the hydrolysis of grape glycosides, and the synthesis and hydrolysis of esters. Yet, other reactions can lead to the production of biogenic amines and ethyl carbamate by some LAB strains with negative consequences to wine safety.
LAB distribution and their succession in musts, in wine, and during vinificationAlthough it is not possible to have a clear definition of lactic acid bacteria (LAB), this group of bacteria is mainly characterized by the production of lactic acid as a major catabolic end product from glucose [2]. The other main characteristics of LAB are gram-positive cocci or bacilli, non-sporing, generally nonmotile, catalase negative, aerotolerant, acid tolerant, chemoorganotrophic, and strictly fermentative organisms. In some conditions, such as media
Morphology Fermentation type SpeciesBacilli Facultative heterofermentative