Degradation of free and sulfur-dioxide-bound acetaldehyde by malolactic lactic acid bacteria in white wine

Abstract

Aims: Acetaldehyde is the major carbonyl compound formed during winemaking and has implications for sensory and colour qualities of wines as well as for the use of the wine preservative SO2. The current work investigated the degradation of acetaldehyde and SO2‐bound acetaldehyde by two commercial Oenococcus oeni starters in white wine. Methods and Results: Wines were produced by alcoholic fermentation with commercial yeast and adjusted to pH 3.3 and 3.6. While acetaldehyde was degraded rapidly and concurrently with malic acid at both pH values, SO2‐bound acetaldehyde caused sluggish bacterial growth. Strain differences were small. Conclusions: Efficient degradation of acetaldehyde can be achieved by commercial starters of O. oeni. According to the results, the degradation of acetaldehyde could not be separated from malolactic conversion by oenococci. While this may be desirable in white winemaking, it may be necessary to delay malolactic fermentation (MLF) in order to allow for colour development in red wines. SO2‐bound acetaldehyde itself maybe responsible for the sluggish or stuck MLF, and thus bound SO2 should be considered next to free SO2 in order to evaluate malolactic fermentability. Significance and Impact of the Study: The current study provides new results regarding the metabolism of acetaldehyde and SO2‐bound acetaldehyde during the MLF in white wine. The information is of significance to the wine industry and may contribute to reducing the concentration of wine preservative SO2.

Evaluation of the acetaldehyde production and degradation potential of 26 enological Saccharomyces and non-Saccharomyces yeast strains in a resting cell model system

“…Although formation and degradation kinetics as well as peak acetaldehyde levels are in agreement with values obtained in musts and wines [15,16,20,27,31], further work will benefit from the validation of the method presented here in model and natural grape musts.…”

“…Data display average of duplicate incubations ±SE Superscript letters display statistically significant differences of average values obtained for yeast strains in a column (P \ 0.05) * Displays statistically significant differences of average yield coefficient values obtained for one yeast between the treatment with or without SO 2 (P \ 0.05) § Displays statistically significant differences of average peak acetaldehyde values obtained for one yeast between the treatment with or without SO 2 (P \ 0.05) only lasted between 0.5 and 2 h in this study, and the data obtained were highly reproducible. Both the kinetics of acetaldehyde production and degradation, as well as peak and final values were within the range of values reported from fermentations in musts and wines [15,16,20,27]. In this study, final acetaldehyde values were not considered for the assessment of the yeast acetaldehyde production potential because they highly depended on yeast viability and vitality during the latter phases of incubations.…”

Proton Transfer Reaction Mass Spectrometry: Applications in the Life Sciences

“…The observed degradation of ethanol and acetaldehyde during bacterial growth has been previously reported for bacteria ( [138]; [139]), while acetone is a known fermentation product from other bacterial species [140]. We see that when the levels of acetaldehyde and ethanol become undetectable there is immediately an increase in acetone levels, which suggests a change in metabolism as was also detected for a mixed microbial consortium [141].…”

The application of malolactic fermentation process to create good-quality grape wine produced in cool-climate countries: a review

“…Conversion of SO 2 from the free to bound form (e.g., with acetaldehyde) is a significant problem in winemaking technologies requiring intensification of the sulfitation process. The application of MLF may contribute to a reduction of wine sulfitation and an effective reduction of acetaldehyde concentration [13,[20][21][22][23][24].…”

“…At higher amounts (up to 4 mg/l), it may be produced by spontaneous MLF bacteria, e.g., Pediococcus, while at considerably lower amounts (approximately 0.2 mg/l) by O. oeni, a strain applied in MLF inocula [5,6,[11][12][13]19]. A lack of process control, mainly in terms of temperature and dominant microflora, may result in the appearance of other undesirable fermentation by-products, such as, e.g., biogenic amines, polysaccharides, acrolein, acetic acid, d-lactate, butylene glycol, acetaldehyde, or acetoin [6,13,[20][21][22][23][24]. Biogenic amines are low-molecular weight organic bases formed in general in fermented food and beverages by bacterial metabolism mostly via the activity of specific amino acid decarboxylase.…”