Penn State researchers have developed a new “fingerprinting” method for analyzing procyanidins, complex plant compounds which contribute to the taste and mouthfeel variations in many foods and drinks.
While food scientists have long been able to assess total procyanidin content in food and drink, identifying which specific procyanidins are present and how they correlate to specific perceptions has not been accomplished. In their recent publication, in the Journal of Agricultural and Food Chemistry, the team outlines their in-source fragmentation mass spectrometry based “Condensed Tannin Fragmentation Fingerprinting method”.
The novel method provides a unique new way to differentiate unique procyanidins, providing a pathway to determine how astringent a wine may seem or how healthy a food may be.
"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, also referred to as condensed tannins," said Misha Kwasniewski, associate research professor of fermented beverage science and technology in the College of Agricultural Sciences.
"We wanted to understand the biological activity of taste and mouthfeel, but 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 used their Condensed Tannin Fragmentation Fingerprinting technique to analyze 19 complex samples containing various amounts of condensed tannins. In their testing, they demonstrated that the method could accurately, and with high precision, characterize the tannins present.
The team is now working with Pennsylvania winemakers to improve the quality of their wine which notoriously does not contain "as big a mouthfeel" as wine made in warmer climates.
"We want to learn how winemakers here—whether it be through new breeding programs and new grape varieties, or wine-making techniques or any number of interventions—can make the type of wines that they want to make, and sometimes that will be wines that have greater amounts of astringency," Kwasniewski said.
"The current methods that were available for understanding what was going on with the tannin structure really don't work with Pennsylvania wines."