In a recent review published in the journal Foodsresearchers examined the literature on health-promoting compounds present in wine and related products (such as vinegar and wine alcohol), as well as technological advances in the detection and study of these compounds. They hope this research will inform winemaking and viticulture processes and promote human health while preserving flavor.
Review: Beyond the Bottle: research into health-promoting substances in wine and wine-related products: extraction, detection, quantification, aroma properties and terroir effects. Image credits: Andrii Zastrozhnov / Shutterstock
Benefits of wine consumption
Despite the risks of overconsumption of alcohol, the health benefits of consuming wine in moderate amounts are well known. Wine is often part of the Mediterranean diet and is associated with a longer, healthier life, and preventing disease through lifestyle and diet is preferable to medical intervention.
Wine’s benefits come from its polyphenolic compounds, including flavonoids such as anthocyanins and non-flavonoids such as caffeic acid. These compounds have anti-inflammatory, antioxidant and cardioprotective properties. The byproducts of winemaking, such as cognac, grape seed oil, grape juice concentrates, wine vinegar and nutritional supplements, also contain beneficial bioactive compounds.
“Wine and wine-related products are complex matrices containing thousands of these compounds, many of which have nutraceutical properties.”
The research team reviewed the vast amount of literature on the beneficial substances in wine and the factors that influence their development. To enable further research, they identified research gaps that needed to be addressed and created an essential resource for winemakers and the research community.
The methods used to isolate and study the compounds in wine have different sensitivities and should be chosen based on the compound being studied and the product in which it is found. The strength of polyphenols and other compounds is also affected by environmental factors. The authors point out the need to use adapted and specialized techniques to overcome challenges such as cross-contamination, which can reduce the accuracy of results.
Phenolic and non-phenolic compounds in wine
Phenolic compounds can be classified as flavonoids, non-flavonoids (stilbenes and phenolic acids) and compounds produced after fermentation. Meanwhile, non-phenolic compounds include glutathione, vitamins and minerals.
Phenolic compounds have antioxidant properties; they contribute to good health by reacting with free radicals and preventing cellular damage. Flavonoids can exist independently, but are often found in a polymerized state with sugars, non-flavonoids, or other flavonoids. Flavonoids include flavanones and anthocyanins, which give wine its characteristic color, aroma, flavor and dryness.
“Sensory evaluation plays a crucial role in wines and wine-related products, as it evaluates essential characteristics such as color, clarity, aroma, taste and astringency, such as mouthfeel. However, these sensory characteristics can be modified by the presence of health-promoting compounds, namely polyphenols, and their low solubility.”
Fermentation promotes microbial activity and introduces bioactive products such as hydroxytyrosol, tryptophol and tyrosol. In addition to their documented cardiovascular benefits, they have anticancer, antidiabetic, antiatherogenic, antidiabetic, lipid-regulating, and neuroprotective properties. Some studies show they may reduce liver damage associated with COVID. Drinking wine also releases serotonin and melatonin, which promote healthy sleep and regulate mood.
Wine products contain vitamin A, vitamin C and vitamin E. Vitamin A can improve skin health by preventing macular degeneration associated with aging. Vitamin C strengthens the immune system and supports collagen synthesis, while vitamin E protects against cancer and heart disease. However, the authors note that vitamin concentrations in wine products have not been well studied.
Minerals found in wine products include potassium, calcium, sodium and magnesium, which are crucial for physiological processes such as bone health, electrolytic balance and blood pressure regulation. Glutathione is another important antioxidant, which preserves the compounds in the wine and therefore its taste.
Schematic effect of glutathione in wine and wine-related products.
The role of the environment
The contribution of terroir, or the ecosystem in which a wine is grown, cannot be overstated. Terroir integrates environmental factors such as soil composition, climate and topography with human management practices such as viticultural techniques and the choice of cultivar and vine rootstocks.
The benefits that different wines provide cannot be separated from their environment and growing practices. Soil characteristics influence the sugar and nitrogen content and anthocyanin content in the grapes. Biodiverse vineyards have natural pest control mechanisms, reducing the need for chemical pesticides.
“Different soils contribute different flavors and textures to the grapes, which can be reflected in the wine.”
Small variations in environmental factors lead to differences in grapes and the resulting wine products, including the strength of the phenolic and non-phenolic compounds they contain. They also change the flavor of the wine: grapes growing on volcanic soils may taste smokier, while wines from limestone-rich soils may taste stony or chalky.
Various techniques such as chromatography, spectroscopy, antioxidant tests, enzymatic methods and electrochemical techniques are used to isolate and study useful compounds in wine. The authors caution that the choice of method should be determined by the product being studied and the compound to be isolated. Further systematic studies can encourage the development of viticultural practices that promote human health and environmental sustainability while still producing a delicious bottle of wine.
- Beyond the bottle: research into health-promoting substances in wine and wine-related products – extraction, detection, quantification, aroma properties and terroir effects. Marques, C., Dinis, L., Santos, MJ, Mota, J., Vilela, A. Foods (2023). https://doi.org/10.3390/foods12234277, https://www.mdpi.com/2304-8158/12/23/4277