RUTGERS (US) — New research explains why a nice glass of wine goes well with a hearty steak: the astringent wine and fatty meat are at opposite ends of a sensory spectrum.
The findings, reported in Current Biology, offer a whole new definition of the balanced meal. They also offer a new way of thinking about our eating habits, both good and bad.
The research centers on “mouthfeel”—the sensations caused in the mouth by the physical and chemical interaction between the mouth’s tissues and saliva and the chemicals found in food.
“The mouth is a magnificently sensitive organ, arguably the most sensitive in the body,” says Paul Breslin, professor of nutritional sciences at Rutgers University and the Monell Chemical Senses Center. “The way foods make our mouths feel has a great deal to do with what foods we choose to eat.”
The researchers knew that astringent wines feel rough and dry in our mouths. Fats, on the other hand, are slippery. There was the notion that the two might oppose each other, but it wasn’t quite clear how that might really work. After all, the astringents we consume are only weakly astringent.
Breslin and his colleagues started with the hypothesis that astringency and fattiness were on opposite ends of a continuum, like hot and cold. “It’s impossible for something to be both hot and cold at the same time,” Breslin says. “You can put ice in hot water, but then, it’s no longer hot, is it? And yet, it’s not quite cold, either.”
The researchers asked volunteers to sample fatty foods, alternating with sips of weakly astringent liquid—in this case, alternating tea with salami. “After all, if you’re going to drink wine with steak, you don’t drink an entire glass of wine, and then eat the whole steak,” Breslin says. “You sip, then eat, then sip, then eat.”
In this experiment, the subjects alternated between tea and salami. The researchers also asked subjects to sip tea without tasting the salami. They then asked their subjects to rate the level of fattiness, or slipperiness, they felt in their mouths, and the level of astringency, or dryness.
“By ‘dryness,’ we don’t mean ‘not wet,'” Breslin says. ” We mean the rough, puckering sort of mouthfeel caused by the interaction of astringent chemicals in the food with lubricating proteins in the saliva and mouth tissues.”
They found that their subjects felt more astringency in their mouths as they kept sipping, but that this feeling reached a limit based on the chemical composition of the drink. “This is why, in wine tasting parties, they don’t just have you sip wine after wine, but give you something fatty—cheese, crackers, cold cuts—in between tastings,” Breslin says.
This natural tendency to seek balance in our mouths might have benefits for maintaining a diversity of foods in our diet, Breslin says.
“The opposition between fatty and astringent sensations allows us to eat fatty foods more easily if we also ingest astringents with them,” he says. It might also explain why similar yins and yangs exist in many different styles of cooking.
“There are these pairings almost everywhere you look,” Breslin says. “In traditional French gastronomy, for example, besides having wines between meat courses, you might have a sorbet to ‘cleanse’ your palate of the taste of one course and get you ready for the next.
“In Japanese gastronomy, it might be ginger along with sushi. And most salad dressings are a mix of something fatty with something astringent, like oil and vinegar.”
The research was funded by a grant from the National Institutes of Health and Suntory Business Expert Ltd.