We all know that food is best associated with wine to delightfully complement the aromas of a meal.
Now, French scientists have proven that the reverse is also true – food fats interact with wine compounds to make the drink taste better.
Researchers have explored how lipids – abundant fat molecules in cheese, meat, vegetable oils and other foods – interact with grape tannins.
Tannins are a group of bitter and astringent compounds that are found naturally in plants, seeds, bark, wood, leaves and fruit skins, including grapes.
Scientists say that tannins increase lipids, accentuating their taste and masking their unwanted bitter taste.
Wine lovers recognize that a perfectly paired wine can make a delicious meal taste even better, but the reverse is also true: certain foods can influence the aromas of wines.
WHAT ARE TANNIES?
Tannin, also called tannic acid, is a pale yellow to light brown substance.
It is widely found that occurs naturally in the roots, wood, bark, leaves and fruits of many plants.
Tannin is also called tannic acid
Tannin solutions have an astringent taste and are responsible for astringency, color and some of the aroma of tea.
They are used in the process of clarifying wine and beer, but are mainly used in tanning the skin, dyeing fabrics, making ink and in various medical applications.
Tannins are known to bind to proteins and amino acids, causing them to aggregate and precipitate.
The study was led by Julie Géan and colleagues at the University of Bordeaux, France.
They are said to have deciphered for the first time the interaction between tannins and emulsified lipids at the molecular level.
“Dietary oils lower the perception of astringency of tannin solutions in grapes,” says the team in the Journal of Agricultural and Food Chemistry.
Our results show that dietary lipids are crucial molecular agents that affect our sensory perception during wine consumption.
Good wine already established can make a delicious meal taste even better, such as Cabernet Sauvignon with steak.
Researchers specializing in wine science – known as winemakers – have also noticed mutual interactions between food and wine, such as Chardonnay and Dutch sauce.
Sensory analysis studies have shown in particular that some foods influence the taste of wines, making them more pleasant on the tongue.
However, these combinations of food and wine “are mainly based on empirical considerations without any scientific evidence,” the team says.
The study authors wanted to investigate how tannins influence the size and stability of lipid droplets in an emulsion.
They also wondered how previous consumption of vegetable oils would impact the taste of tannins for human volunteers.
For their experiments, they made an oil-in-water emulsion using olive oil, water and an emulsifier, called phospholipid DMPC.
Olive oil provided lipids, which are generally found in the form of fat globules dispersed in liquids or solids.
Paper images show the emulsion burning in the presence of catechin at the interface of oil droplets, stabilized by the phospholipid DMPC used as an emulsifier.
Then, they added a grape tannin, called catechin, and studied the lipids in the emulsion with nuclear magnetic resonance and optical and electron microscopy.
The team found that the catechin was inserted into the emulsifier layer that surrounded the oil droplets, causing larger droplets to form over time.
This caused something called “cremation” – the top of the emulsion (the richest in lipid droplets) became creamy, while the bottom became transparent.
This result demonstrates that the tannin promotes burning, and these larger lipid drops mask the astringent taste of the tannins.
The image shows emulsion drops in the presence and absence of catechin, a type of tannin. The addition of catechin caused a pronounced “cremation”
The researchers then tested the effect in the human mouth, using three different sources of lipids.
In the taste tests, volunteers indicated that consuming a tablespoon of rapeseed, grape seed or olive oil before tasting a tannin solution reduced the astringency of the compounds.
Olive oil had the greatest effect, making tannins be perceived as fruit instead of astringent.
In the mouth, tannins can also make oil droplets less available to bind to saliva proteins and cause astringency.
The study highlights the importance of oils on the perception of the taste of tannin solutions depends on the variety of oil.
“Rapeseed and grape oils reduce or even eliminate the astringency of tannin solutions, while tannin solutions are no longer perceived as astringents, but as fruits after the addition of olive oil,” say experts.
The team concluded that there is a “reciprocal affinity” between tannins and lipids, as well as components of biological membranes or fatty foods.
They believe that tannin-lipid interactions should be considered by wine experts to find the best association between highly astringent red wines and fatty foods such as cheese, meat, delicacies or desserts, for example.
Why some red wines have a “dry” taste: Cab Sauv contains more tannins, larger and more pigmented, which mix with saliva to influence the astringency of a bottle than a Pinot Noir
An interaction between the tannin in the wine and your saliva could eventually explain why some are considered “drier” than others, according to a new study (stock image)
An interaction between wine tannins and saliva could explain why some are considered “drier” than others, a 2019 study found.
While compound tannin has long been associated with the sense of mouth, the exact way it causes it has never been sharp.
The tannin extracted from drier wines such as Cabernet Sauvignon proved to be larger and more pigmented than those from less dry Pinot Noir.
When this “drier” tannin was added to control drinks, it promoted perceptions of dryness.
The feeling of dryness, also known as astringency, refers to a strange or harsh sensation in the mouth when someone drinks wine.
The findings could help winemakers better manage wine tastes, the researchers say.
Read more: Tannin and saliva interactions influence the “mouthfeel” of the wine