We all know that food is best paired with wine to delightfully complement the flavours of a meal.
Now, French scientists have proved that the reverse is also true – fats in food interact with compounds in wine to make the drink taste better.
The researchers explored how lipids – fatty molecules abundant in cheese, meats, vegetable oils and other foods – interact with grape tannins.
Tannins are a group of bitter and astringent compounds found naturally in plants, seeds, bark, wood, leaves and fruit skins, including grapes.
The scientists say tannins enlarge lipids, accentuating their taste and masking their undesirable bitter taste.
Wine lovers recognise that a perfectly paired wine can make a delicious meal taste even better, but the reverse is also true: Certain foods can influence the flavors of wines
WHAT ARE TANNINS?
Tannin, also called tannic acid, is a pale-yellow to light-brown substances.
It is widely found occurring naturally in in the roots, wood, bark, leaves, and fruit of many plants.
Tannin is also called tannic acid
Tannin solutions have an astringent taste and is responsible for the astringency, colour, and some of the flavour in tea.
They are used in the clarification process of wine and beer but is mainly used in tanning leather, dyeing fabric, 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 has been led by Julie Géan and colleagues the University of Bordeaux, France.
They say they’ve deciphered the interaction between tannins and emulsified lipids at the molecular level for the first time.
‘Dietary oils decrease the perception of astringency of grape tannin solutions,’ the team say in the Journal of Agricultural and Food Chemistry.
‘Our results highlight that dietary lipids are crucial molecular agents impacting our sensory perception during wine consumption.’
It’s already established good wine can make a delicious meal taste even better, like Cabernet Sauvignon with steak.
Researchers who specialise in the science of wine – known as enologists – have also noted mutual interactions between food and wine, such as Chardonnay and hollandaise sauce.
Sensory analysis studies have notably shown that some foods influence the taste of wines, making them more pleasurable on the tongue.
However, these combinations between foods and wines ‘are mainly based on empirical considerations without any scientific evidence’, the team say.
The study authors wanted to investigate how tannins influence the size and stability of lipid droplets in an emulsion.
They also wondered how the prior 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 a emulsifier, called DMPC phospholipid.
Olive oil provided the lipids, which are generally found as fat globules dispersed in liquids or solids.
Images from the paper shows emulsion creaming in the presence of catechin located at the interface of the oil droplets, stabilised by the DMPC phospholipid used as the 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 catechin inserted itself into the layer of emulsifier that surrounded the oil droplets, causing larger droplets to form over time.
This caused something called ‘creaming’ – the top of the emulsion (the richest in lipid droplets) turned creamy, while the bottom turned transparent.
This result demonstrates that tannin promotes creaming, and these bigger lipid droplets mask the astringent taste of tannins.
Image shows emulsion droplets in the presence and in the absence of catechin, a type of tannin. Addition of catechin caused pronounced ‘creaming’
Researchers then tried the effect in the human mouth, using three different sources of lipids.
In taste tests, volunteers indicated that consuming a spoonful of rapeseed, grapeseed or olive oil before tasting a tannin solution reduced the astringency of the compounds.
Olive oil had the greatest effect, causing the tannins to be perceived as fruity 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 taste perception of the tannin solutions depends on the oil variety.
‘Rapeseed and grapeseed oils reduce or even remove the astringency of the tannin solutions while tannin solutions are no longer perceived as astringent but as fruity after the intake of olive oil,’ the experts say.
The team conclude that there is a ‘mutual affinity’ between tannins and lipids, as well as components of biological membranes or fatty foods.
They believe 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, deli meats or desserts, for example.
Why some red wines taste ‘dry’: Cab Sauv contains more, larger and more highly pigmented tannins which mix with saliva to influence the astringency of a bottle than a Pinot Noir
An interaction between tannin in wine and your saliva could finally explain why some are deemed ‘drier’ than others, a new study shows (stock image)
An interaction between tannins in wine and saliva could explain why some are deemed ‘drier’ than others, a 2019 study revealed.
While the compound tannin has long been associated with the mouthfeel, exactly how it causes it has never been pin pointed.
Tannin extracted from drier wines such as Cabernet Sauvignon was shown to be larger and more highly pigmented than those in the less dry Pinot Noir.
When this ‘drier’ tannin was added to control drinks, it promoted perceptions of dryness.
The dryness sensation, also known as astringency, refers to a puckering or rough feeling in the mouth when someone drinks wine.
The findings could help winemakers better manage wine tastes, say researchers.
Read more: Tannin and interactions with saliva influence the ‘mouthfeel’ of wine