Effects of reduced levels of sulfite in wine production using mixtures with lysozyme and dimethyl dicarbonate on levels of volatile and biogenic amines

Exploring factors influencing the levels of biogenic amines in wine and microbiological strategies for controlling their occurrence in winemaking

Fermented beverages, including wine, can accumulate high concentrations of biogenic amines (BAs), which can pose potential health risks. BAs are produced by various yeasts and lactic acid bacteria (LAB) during winemaking. LAB are the main contributors to the formation of histamine and tyramine, the most toxic and food safety relevant biogenic amines. Numerous factors, ranging from agricultural and oenological practices to sanitation conditions, can contribute to the formation of BAs in wines. Moreover, organic and biodynamic wines impose limitations on the use of common food additives employed to control the proliferation of native and spoilage microorganisms during vinification and storage. To mitigate histamine production, commercial starter cultures incapable of synthesising histamine have been effectively utilised to reduce wine histamine content. Alternative fermentative microorganisms are currently under investigation to enhance the safety, quality, and typicity of wines, including indigenous LAB, non-Saccharomyces yeasts, and BAs degrading strains. Furthermore, exploration of extracts from BAs-degrading microorganisms and their purified enzymes has been undertaken to reduce BAs levels in wines. This review highlights microbial contributors to BAs in wines, factors affecting their growth and BA production, and alternative microorganisms that can degrade or avoid BAs. The aim is to lessen reliance on additives, providing consumers with safer wine choices.

Natural versus conventional production of Spanish white wines: an exploratory study

BACKGROUND

Natural wine (NW) lacks an official or agreed definition, but it can be generally described as a wine produced with organic or biodynamic grapes with minimal intervention in the cellar, and with minimal or no use of oenological additives. The present study aimed to test the hypotheses that self-defined NWs differ from conventional wines (CW) in their chemical composition and main sensory characteristics. The levels of conventional oenological parameters, turbidity, biogenic amines, ochratoxin A, ethyl carbamate, sulphites, chlorides, some metals, major, trace and Strecker aldehyde volatile compounds were determined in 28 wines, including natural and conventional Spanish commercial white wines. Wines were also sensory described following a labelled free sorting task.

RESULTS

NWs presented higher pH, volatile acidity (VA) and turbidity values, and a more intense yellow colour, whereas they have a lower malic acid content compared to theor conventional counterparts. NWs presented lower levels of total sulphur dioxide but significantly higher levels of biogenic amine putrescine, although both compounds are within the legal limits in all cases. None of the dimensions of the similarity space discriminated NWs from CWs. However, 70% of the NWs were grouped on the basis of various aromatic defects related to their higher content in 4-ethylphenols and VA. The remaining 30% were not differentiated from their conventional counterparts.

CONCLUSION

It could be confirmed that NW can be globally differentiated from CW with respect to to their chemical and their sensory profiles, whereas the content in toxicants was not significantly different, with the exception of total sulphur dioxide and putrescine levels. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Evaluation of grape stems and grape stem extracts for sulfur dioxide replacement during grape wine production

Sulfur dioxide (SO₂), the main preservative in wine, may affect the sensory properties of the wines, as well as cause allergic reactions and headaches in sensitive people. The aim of this work was to evaluate the replacement of SO₂ in Tempranillo wines with Mazuelo grape stem products. Five Tempranillo red wines were elaborated: positive control (60 mg/L SO₂); negative control with no preservatives; Mazuelo extract (200 mg/L); Mazuelo extract combined with SO₂ (100 mg/L + 20 mg/L); and Mazuelo stem (400 mg/L). The oenological parameters, antioxidant capacity, total phenolic (TP), total flavonoids (TF) and total anthocyanins (TA) contents were determined. Additionally, individual phenols were analyzed by HPLC-DAD-FLD. The spectrophotometric analyses showed that the wines had similar antioxidant capacities and concentrations of TP and TF. However, TA was more affected by the lack of SO₂ as anthocyanins presented higher concentrations in positive control samples. The concentrations of individual phenols followed a similar path in all samples. Wines containing sulfites were more similar than the other treatments. However, these similarities were not reflected on the sensory analysis performed, as triangle test did not show differences between the wine with extract addition and the positive control wine. Therefore, Mazuelo stem extract could be a possible strategy for SO₂ replacement. Nevertheless, further studies are necessary to confirm the potential of grape stem extracts as wine preservative.

Sulfur dioxide-free Verdejo wines through the use of a pure stilbene extract: exploring possible synergistic effect with glutathione

BACKGROUND

The search for alternatives to sulfur dioxide (SO₂ ) in white wine production is a tough challenge for the oenological industry. The current article investigates the effectiveness of several preservatives in protecting Verdejo white wines. The following wines were elaborated: without preservative (CT wines), with SO₂ (SO₂ wines), with stilbene-enriched extract (ST99 wines), with glutathione (GSH wines) and finally with the combination stilbene extract plus glutathione (ST99-GSH wines).

RESULTS

ST99 extract preserved the wines from malolactic fermentation (MLF), maintained the quality parameters of the wines, but affected their color from the beginning of the process. Synergistic effects between ST99 and GSH were found for oxygen consumption rates, related to oxidation processes. The content of amino acids and biogenic amines was slightly affected by the treatments, but the quality or safety of the wines was not compromised. However, after 12 months of ageing in bottle, the SO₂ wines showed the highest score in the sensory analysis. The reasons for the evolution of treated wines and the implications of this study for maintaining the quality of free SO₂ white wines are discussed.

CONCLUSION

ST99 may be proposed as an alternative to SO₂ in wines to be consumed in the short term. Its combination with GSH does not prolong its shelf-life. © 2022 Society of Chemical Industry.

Use of fumaric acid to control pH and inhibit malolactic fermentation in wines

Fumaric acid is an additive allowed by the Codex Alimentarius and under evaluation by the International Organisation of Vine and Wine (OIV) that can be used for wine acidification but also to inhibit malolactic fermentation (MLF). The use of 300-900 mg/L of fumaric acid can inhibit MLF in red wines decreasing pH by 0.2 units or more depending on the buffer capacity. When MLF was running with populations of either 7 or 8 log CFU/mL strain alpha (Oenococcus oeni) the application of 600 mg/L of fumaric acid stopped the process for more than 50 days and cells were undetected in specific media. In triangular tastings, fumaric acid was not detected at 300-600 mg/L (p < .05). In subsequent preference tests, some tasters perceived more acidity and body. Fumaric acid is a useful technological additive to improve wine microbiological stability and freshness, also allowing reduction of SO₂ levels.

Electrochemical triggering of the Chardonnay wine metabolome

Oxidation of wine upon bottle ageing is a crucial matter of concern for the qualitative long-term storage of white wines. However, understanding the various molecular mechanisms potentially involved, which can impact the wine composition, requires that top-down analytical strategies are implemented. Here, we report the analysis of bottle aged Chardonnay wines made from the same must, but differing by the amount of SO₂ initially added to the must at pressing (0 and 8 g·h L^-1). Metabolomics fingerprints obtained from electrochemical simulation of oxidative reactions were obtained by coupling of either on-line or off-line electrochemical oxidation to FT-ICR-MS detection. We reveal that, whatever the electrochemical DC voltage is, wines with initial SO₂ addition displayed molecular fingerprints, which remained more similar to the non-oxidized wine without initial SO₂ addition. We further show that a diversity of sulfur-containing compounds appeared to be the most sensitive to oxidation, whereas nitrogen-containing compounds were mostly formed.