Influence of supplementation with different oenological tannins on malvidin-3-monoglucoside copigmentation

Abstract

Abstract. The effect as copigment of (-)-epicatechin and five different oenological tannins has been measured in a model wine solution containing malvidine-3-monoglucoside. The results show that all oenological tannins exert a positive effect on the color of the malvidine solution, increasing the global absorptivity spectrum and changing the Cielab coordinates. Specifically, supplementation with oenological tannins increase a* and b* and decreases L*. Overall, the effect as copigments of all oenological tannins was higher than that of (−)-epicatechin.

Recent advances of the OIV working group on oenological tannins in the study of the functionalities of oenological tannins

“…These results confirm that oenological tannins protect wine against oxidation because they exert antioxidant capacity [3], they consume directly oxygen [5] and they inhibit laccase activity [6]. Moreover, they can improve and stabilize the color of red wines since they act as copigments [7][8][9]. As a fruit of these results the OIV resolutions Oeno-Techno 17-612 [10] and Oeno-Techno 17-613 [11], now in step 7, propose to include two new objectives of the use of tannins in must and wine that will be probably approved in the next 17 th General Assembly of OIV.…”

New insight about the functionality of oenological tannins; Main results of the working group on oenological tannins

“…The aim of this communication was to synthetize all the results obtained up to the current date. Some of these results have been previously published [3,4,10,19].…”

“…The samples were m aintained in airtight conditions. A week later, the full absorbance spectrum in the visible range (400-800 nm) was measured according with the procedure described by Gombau et al (2016) [10]. Figure 1 shows the principal component analysis corresponding to the chemical composition of the thirtysix different commercial tannins.…”

“…Nevertheless, it is incontestable that oenological tannins are also currently used for many other purposes. Indeed, the literature has attributed several other functionalities to oenological tannins, such as antioxidant activity (protection of wines against oxidation) [3], direct consumption of dissolved oxygen [3,4], ability to scavenge peroxyl radicals [5], ability to chelate iron (II), prevention of oxidative damage mediated by Fentonbased reactions [6], antioxidasic activity (anti-laccase activity) [7], improvement of wine structure and mouthfeel [8], color improvement and stabilization of red wines [9], copigmentation effect [10], direct formation of new pigments [1], elimination of reduction odors [8] and even bacteriostatic effects [11].…”

Evaluación de la composición y calidad del color de vinos tintos Tannat elaborados por maceración pre-fermentativa en caliente

“…Otras, proponen el uso de agregados externos (taninos o manoproteinas entre otros) para estabilizar el color [7,8].…”