Wine brewing is a complicated process. Grape varieties, "local customs" of producing areas and every link in the brewing process will have an impact on the flavor of wine, so wine appreciation has become a mysterious knowledge. However, a paper published in PLOS I on March 18 found that our brains may have a soft spot for wines with low alcohol content.

The Shell scientist is very interested in the first author of this article, Lyme of Hebrew University in Israel. Professor Ram Frost gave an exclusive interview. Professor Frost told Shell.com that his love for wine has a long history. After years of research, he has accumulated a lot of knowledge about wine brewing and tasting, and the theme of this study is also closely related to this interest.

Professor Frost and others have noticed that in the past two or three decades, the alcohol content of wines sold in the market has become higher and higher. Thirty years ago, wines with an alcohol content of 12% or 12.5% were the most common. Today, most wines have an alcohol content of 14% or above. Part of the reason for this trend is that wine makers infer the taste of the public. After all, many people think that highly alcoholic wine is strong and mellow. However, some wine tasting experts have raised objections to this. They think that excessive alcohol content will mask the subtle taste and charm of wine itself.

If you are a wine producer, should you listen to your intuition or expert advice at this moment? What kind of wine is more likely to attract consumers to pay? The article points out that the olfactory and gustatory activities closely related to wine tasting are both chemical sensory channels that are difficult to quantify and are easily influenced by other factors. Therefore, it is not easy to obtain reliable results about taste preference. Therefore, the researchers decided to use functional magnetic resonance imaging (FMRI) technology to record the brain activity induced by wine with different alcohol content without subjective judgment.

The researchers selectively recruited a group of volunteers through questionnaire screening. These volunteers have the habit of drinking wine on weekdays, but the number of purchases does not exceed once a week. In the experiment, the researchers asked the subjects to drink three liquids in random order while receiving fMRI: (1) low-alcohol wine, (2) high-alcohol wine, and (3) tasteless solution made of 12.5 mM potassium chloride and 1.25 mM sodium bicarbonate.

In order to eliminate the interference caused by variables other than alcohol content to the maximum extent, the researchers strictly controlled the wine samples used in the experiment. First of all, the origin, grape variety and year of each pair of high/low alcohol wines are consistent with the market price; Secondly, after determination, the residual sugar content of the two wines is also very close to pH value; Thirdly, the researcher * * * prepared four groups of high/low alcohol wines, and provided one group to each subject at random; Finally, volunteers scored the wines they drank after fMRI scanning, and the results showed that their subjective preferences for the two wines were almost the same.

The analysis of fMRI data shows that compared with odorless liquid, wine significantly activates many brain regions involved in taste processing, including cingulate cortex, central posterior gyrus, rolandic lid, ventral postmedial thalamus and cerebellum.

When comparing the neural activity caused by two kinds of alcohol, the researchers found an unexpected result. Contrary to people's impression that alcohol with high alcohol content is "rich in flavor", alcohol with low alcohol content causes stronger activity in the right insula and cerebellum, which are related to the processing of taste intensity (pictured).

The subjects' subjective evaluation of the two wines is almost the same, but the objective brain activity signals are different. Why is this happening? Professor Frost told the fruit tree network that when the alcohol content is low, the brain may be able to explore the aroma and taste of wine more deeply, which may lead to a more active neural response, which is not controlled by subjective consciousness, and may also have nothing to do with people's preference for alcohol level. Interestingly, although the volunteers who participated in the experiment were all ordinary consumers, their brains coincided with those of some wine tasting experts.

Although this result does not directly reflect people's actual preference for alcohol content, the wine manufacturing industry can still get some enlightenment from it. Professor Frost pointed out that one of the great significance of this study is to propose a measurement method. Even if it is a complex chemical sensory stimulus like wine, the brain's response to them can be checked by fMRI technology. "Other characteristics of wine, such as acidity and tannin content, can also be studied in the same way." In the next experiment, researchers will also use functional magnetic resonance imaging to scan wine spectator to see how their brains will react. (Editor: You Zhiyu)

reference data

Frost r, Qui? What can the brain teach us about winemaking? Functional magnetic resonance imaging study on alcohol concentration preference [J].PloS one, 20 14,10 (3): E 019220-E 019220.