Wine lovers know that a well-paired wine enhances the flavors of the food one consumes, while a poorly paired wine does the opposite. And some foods, in turn, can affect the taste of a wine. Is there a better accompaniment to one’s favorite cheeses and / or baked meats than a good bottle of Bordeaux or a California Cabernet? A team of French scientists has specifically investigated the role of interactions between tannins in wine and fatty molecules, known as lipids in food, to better understand what happens at the molecular level with such complementary pairings, according to a recent article in the Journal of Agricultural was published. and Food Chemistry.
Of course, wine taste is highly subjective to the individual; we all have different combinations of taste receptors that affect how we perceive flavors. However, some characteristics are quantifiable: bitterness, sweetness, acidity and the body (or weight) of a wine. It is the basis for the art and science of wine pairings in most fine restaurants. The tannins in wine are polyphenolic compounds that are responsible for much bitterness and contraction in a given wine; it comes from the skins and stems of the grapes, or due to aging in oak barrels. Tannins go well with proteins and fats, which offset their austerity and bitterness. That’s why wines with a heavier tanning ingredient (like Cabernet Sauvignon or Barolo) go so well with cheeses and charcuterie.
The amount of residual sugar – how much sugar remains after fermentation – determines the sweetness of a wine. Many dry wines have almost no residual sugar, while many sweet wines such as dessert, such as Sauternes or tokays, contain high sugars. Sweeter wines, for example, go well with spicy cuisine, as the sugar contrasts with the heat of the food. Acidity is a measure of how acidic a given wine is, and there are three primary acids in wines. Malic acid gives a kind of green apple flavor; lactic acid gives a milky component; and tartaric acid will give wine extra bitter aromas. Wine that is more acidic has been linked to fatty, oily, rich or salty foods, as the acids will compensate for the properties in the palate.
Finally, the amount of alcohol affects how much body (or weight) a wine has, and this gives a perception of heat in the palate. The higher the alcohol content (and the more tannins present), the higher the perception of heat. Conventional wisdom has long held that white wines go well with fish or poultry, while reds are paired with heavier meats. But the reality is more complex. There are heavier, richer white wines (like chardonnay) and lighter red wines (like Beaujolais). It is the weight or body of the wine that should be taken into consideration when making such a pair.
The French scientists focused their research on the tannins, especially how these compounds affect the size and stability of fat globules (lipids) in an emulsion – a common model used in experimental food studies. Therefore, they created their own emulsions in the laboratory from olive oil, water and a phospholipid emulsifier, and they added a grape tannin called catechin. Thereafter, the researchers analyzed the emulsions using a variety of techniques, including optical microscopy, electron microscopy, and nuclear magnetic resonance spectroscopy, as well as measuring droplet size with static light scattering. Their analysis showed that the presence of the grape tannin caused larger oil droplets to form.
Let’s lipid
The researchers then conducted a sensory evaluation and recruited a group of male and female students from the engineering department at the University Institute of Technology in Bordeaux in Périgueux, France. The participants were trained and taught for two weeks to arrange aqueous solutions of different concentrations (citric acids, caffeine, potassium aluminum sulphate) and to recognize common wine aromas, especially those related to oils and tannins (especially the global intensity of taste, acidity, fruity, herbaceous, dried fruit, bitterness, contraction and persistence of taste). The group sniffed five isolated aromas randomly selected from a possible 24 and learned to identify them.
Participants were then asked to taste different tannin solutions alone or after putting down a spoonful of rapeseed, grape seed or olive oil. The results showed that the oils reduced the contraction of the compound, especially the olive oil, which according to the participants made the tannins taste fruity. The French researchers concluded from all this that tannins interact with droplets of oil in the mouth, making the oils less likely to bind to proteins in saliva, causing the astringent taste.
“Dietary oil can reduce the contraction caused by vegetable tannins,” the authors wrote. “These findings confirm the mutual affinity between tannins and lipids, as well as components of … fatty foods. Therefore, tannin-lipid interaction should now be considered by winemakers to find the best link between too many astringent red wines and fatty foods such as for example cheese, meat, delicacies, or desserts. ‘
DOI: Journal of Agricultural and Food Chemistry, 2021. 10.1021 / acs.jafc.0c06589 (On DOIs).