Cheese and wine by themselves taste good, but pairing them can actually enhance their flavor to make the meal even more delicious. Why is that? Well, who was better qualified to answer this question than a team of French researchers, who recently published a paper showing that tannins in wine have an affinity for lipids (fats) in certain foods, such as cheese, meats, and vegetable oils.

Tannins are polyphenolic compounds responsible for the bitterness and astringency of red wines, although some white wines have tannin too from aging in wooden barrels for fermenting skins of grapes.

Along with other qualities, such as acidity, alcohol, and fruit, tannin content is a key characteristic that helps balance a wine. It can also determine how well a wine pairs with certain foods.

In their most recent study published in the Journal of Agricultural and Food Chemistry, researchers at the University of Bordeaux investigated how tannins influence the size and stability of lipid droplets in an emulsion.

During an experiment, the French researchers made an oil-in-water emulsion by mixing olive oil, water, and a phospholipid emulsifier into which they added a grape tannin called catechin. After the tannin was added to the emulsifier that surrounded the oil droplets, the droplets grew in size.

In another experiment, the researchers studied how human volunteers experienced the taste of tannins. When the participants ate a spoonful of rapeseed, grapeseed, or olive oil immediately before tasting a tannin solution, the reported astringency was reduced. The greatest effect was seen when the tannins were combined with olive oil, causing the tannins to be perceived as fruity rather than astringent.

The two evaluations — one assessing sensory perception, the other analyzing the chemical makeup of the emulsions — led the authors to conclude that the tannins interacted with droplets of oil in the mouth. As a result, the oils are less able to bind to proteins in saliva, which is what is responsible for astringent taste.

“Wine is very often consumed with a meal. However, although it is well known to tasters that the taste of wine changes in the presence of food, the influence of dietary lipids on wine astringency and bitterness caused by grape tannins is not well established from a molecular point of view,” the authors wrote in their study.

“Our results highlight that dietary lipids are crucial molecular agents impacting our sensory perception during wine consumption.”