Balancing mouthfeel: The ‘yin and yang’ of sensory perception

It may seem obvious to many that a glass of wine or a nice cup of tea can offer the perfect accompaniment to a meal, but exactly why this is so has remained a bit of a mystery.

Now researchers from Rutgers University and the Monell Chemical Senses Center, USA, believe they may have the answer. 

Speaking with FoodNavigator, Paul Breslin, lead author of the new research, said that finding an overall balance between fatty and astringent mouthfeel could be help industry improve the overall enjoyment of foods.

“We wanted to test the idea that there is a spectrum of oral lubrication sensations – with a creamy/fatty/greasy mouthcoating at one end and a dry/astringent feeling at the other,” ​explained Breslin.

He said the group’s findings – published in Current Biology​ – suggest astringent and fatty ingredients are like ‘the yin and yang of the food world’, sitting on opposite ends of a sensory spectrum.

"The opposition between fatty and astringent sensations allows us to eat fatty foods more easily if we also ingest astringents with them,"​ he said.

Industry impact​

Breslin believes his findings could be important for the food industry that “needs to pay attention to the fact that consumers will want to finish a product or a meal with their mouth feeling balanced in its lubrication.” ​

He said while it may seem common sense, and noted that ‘many or most’ fatty foods in meals are partnered with an astringent – for example red wine and steak or pickled ginger with sushi – there is an interesting question of whether certain pairings make more sense “because of the oral sensory properties of the fats and astringents involved.”​

Exploring the balance​

Breslin suggested that if fatty and astringent feelings really were are at opposite ends of a single continuum, “then they should not be able to co-exist and they should oppose or cancel one another, just as hot and cold do at opposite ends of a sensory thermal continuum.”​
“We tested this by asking if tea would cancel out the fatty mouthfeel of eating salami better than sipping water,”​ he said. The tea worked better.

“We also wanted to know how a weakly astringent beverage such a tea or red wine could counter a very fatty meal such as a burger and fries or a steak,”​ said the sensory expert.

“The answer lay in the fact that astringency grows with repeated samples,”​ he explained. “As we sip tea or wine over the course of a meal the astringency will grow also and this will counter the strong fatty mouthfeel.” ​

In this way, by the end of meal, the fatty and astringent food leave ‘a happy medium’ of not overly lubricated and not underlubricated mouthfeel, he says.