Perceptions of richness in some sparkling wines may be enhanced by compounds working behind the scenes to create ‘kokumi’ sensations, according to a study in the Journal of Agricultural and Food Chemistry published in November.
Researchers only looked at Trentodoc (Trento DOC) Italian sparkling wines, but said their work was a ‘first step’ and could have broader significance.
Kokumi is a Japanese term that has been used in the food world to refer to richness and mouthfeel. It doesn’t represent a particular flavour, although it sits alongside the five basic tastes of umami, sweet, sour, bitter and salty.
The study authors described the process as ’a combination of compounds that work together to enhance flavours and provide richness’, according to journal publisher the American Chemical Society.
Previous studies have looked at the the development of kokumi character in foods, such as cheese, beer and garlic, but it hasn’t been so widely studied in wine.
Many factors in the vineyard and cellar can impact wine characteristics in the glass.
The researchers noted that earlier studies identified glutathione and several other short peptides as contributing to a kokumi sensation in food.
They analysed Trentodoc classic-method sparkling wines spanning five vintages and found 50 oligopeptides that might be responsible for a ‘kokumi’ effect.
This list was shortened to 11 after tests using a computer-simulated version of human calcium-sensing receptors (CaSR). This protein is necessary to trigger kokumi sensations.
Analysis on another 34 Trentodoc wines confirmed that the 11 compounds were widely present in this style of wine, said the authors, who received funding from the autonomous province of Trento.
By the end, they pinpointed one compound, the dipeptide Gly-Val. It enhanced flavour when added to wine samples, said the study authors.
They said their work was a first step in describing the molecular foundations of kokumi sensations in wine.
Fulvio Mattivi, a study co-author and of the Fondazione Edmund Mach, said: ‘In light of these results, it will be necessary to further investigate the role of winemaking technology and yeasts in releasing kokumi oligopeptides derived from the grape proteins, bringing further richness to classic sparkling wines, and extending the investigation to other wine styles as well.’
