Effect of malolactic fermentation on the aroma properties of Tannat wine

Abstract

Descriptive sensory profiles of Uruguayan Tannat wines following malolactic fermentation (MLF) with Oenococcus oeni were compared with control wines where MLF was prevented. MLF led to a significant decrease (P < 0.05) in secondary descriptors such as ‘berry fruit’ and ‘fresh vegetative’, as well as a decrease in related tertiary descriptors such as ‘blackcurrant’, ‘apricot’, ‘cut green grass’ and ‘green pepper’. The main differences in the chemical composition of Tannat wine aromas following MLF were (1) an increase of the lactates (mainly ethyl lactate) over the sensory threshold; (2) a significant decrease in ethyl esters and acetates, depending on the bacteria strain utilised (the most significant change was found in hexyl acetate), and (3) a small increase of 4‐vinylguaiacol and 4‐vinylphenol with one of the MLF strains (this change was below the threshold of human perception). We also observed an increase of compounds related to α‐ketoglutarate metabolism, namely: ethyl 4‐hidroxibutanoate and γ‐butyro‐lactone. Differences in chemical composition due to MLF are discussed in relation to variation in sensory profiles.

Malolactic Fermentation: The ABC’s of MLF

“…This was supported by the findings of Gámbaro et al (2001), which only saw a small increase in 4-vinylguaiacol and 4-vinylphenol in Tannat wines that underwent MLF. These levels were below the odour threshold.…”

“…They reported increases in isoamyl acetate, ethyl caproate and 2-phenylethyl acetate. Similarly, Gámbaro et al (2001) found that ethyl-and acetate ester levels decreased during MLF, but these changes were also dependant on the strain of bacteria used. This coincided with a significant decrease in sensory descriptors like 'berry fruit' and 'fresh vegetative'.…”

“…1 Lonvaud-Funel, 1999;Maicas et al, 1999;Nielsen & Richelieu, 1999;Gámbaro et al, 2001;Bartowsky et al, 2002b;D'Incecco et al, 2004;Swiegers et al, 2005). Jeromel et al (2008) found MLF wines to be preferred compared to non-MLF wines and as being more round and full in taste.…”

Comparative metabolic profiling to investigate the contribution ofO. oeniMLF starter cultures to red wine composition

“…According to previous reports, modiWcation of wine aroma induced by MLF is far more complex and often involves changes in fruity, Xowery, and nutty attributes, and reduction of vegetative, green, grassy, and herbaceous aromas [2,28]. A signiWcant increase in the concentration of several esters produced by bacterial metabolism has been reported [11,39], whereas other studies reported reduced ester concentrations [24]. The catabolism of acetaldehyde by wine LAB was reported by Osborne et al [48].…”

Selection and characterization of Oenococcus oeni strains for use as new malolactic fermentation starter cultures

“…Many aroma changes also happen during MLF to improve the aroma complexity of wine (Maicas et al 1999;Gambaro et al 2001;Liu 2002;Pozo-Bayón et al 2005; Bartowsky and Borneman 2011). MLF is a secondary fermentation that usually occurs during the storage of young wines, or several weeks after alcoholic fermentation (AF).…”