Ever wonder why some red wines or dark chocolates feel silky smooth, while others leave your tongue feeling dry and puckered? It all comes down to procyanidins, complex plant compounds also known as condensed tannins. Until now, scientists could only measure how much was in a food, not which ones were responsible for specific sensations.
That’s changing thanks to researchers at Penn State, who developed a new method called Condensed Tannin Fragmentation Fingerprinting. It uses mass spectrometry to break tannins into fragments, allowing researchers to identify and quantify the specific types involved.
“Drinking red wines, sometimes that tannic element is really harsh, like dragging sandpaper across your tongue, and sometimes it is velvety or smooth — and yet those two wines can have the same absolute amount of procyanidins,” said senior author Misha Kwasniewski, associate research professor of fermented beverage science and technology at Penn State. “This goes beyond taste and mouthfeel because procyanidins also are responsible for antioxidant activity and health-related benefits, and current analytical methods often show a lack of correlation with biological activities and health-related benefits.”
The team validated the method by testing 19 complex samples with known tannin profiles and analyzing eight commercially available ciders. The results confirmed the technique’s accuracy and real-world relevance.
Now, Kwasniewski’s team is working with winemakers in Pennsylvania — where cooler climates can lead to wines with a milder mouthfeel — to explore how grape variety, breeding or fermentation methods can impact tannin profiles.
The research, published in the Journal of Agricultural and Food Chemistry, was supported by the U.S. Department of Agriculture’s National Institute of Food and Agriculture and the Crouch Endowment for Viticulture, Enology, and Pomology Research at Penn State.