Department of Agricultural Sciences, Grape and Wine Science Division, University of Naples "Federico II", Viale Italia (Angolo Via Perrottelli), 83100 Avellino, Italy.
Biolaffort, 126 Quai de la Souys, 33100 Bordeaux, France.
Molecules. 2020 Oct 10;25(20):4607. doi: 10.3390/molecules25204607.
In the wine industry, in addition to condensed tannins of grape origin, other commercial tannins are commonly used. However, the influence of oxygen uptake related to different tannin additions during the post fermentative phase in wine has not been completely investigated. In this study, we evaluated the influence of four different commercial tannins (namely, condensed tannins, gallotannins, ellagitannins and tea tannins) during four saturation cycles.
Wine samples were added with four different tannin classes (30 g/hL) as to have 5 different experimental samples: control, gallotannins (GT), condensed tannins (CT), ellagitannins (ET), and tea tannins (TT). The chemical composition of the four commercially available tannin mixtures was defined by means of NMR and high-resolution mass spectrometry. After the addition of tannins, each wine sample was oxidized by air over four cycles of saturation. During the experiment oxygen consumption rate (OCR), sulfur dioxide consumption, acetaldehyde production, phenolic compounds, chromatic characteristics, astringency measured by the reactivity towards saliva proteins and astringency subqualities were evaluated.
The experiment lasted 52 days. The addition of tannins influenced the oxygen consumption on the 1st day of the saturation cycles and, in the case of TT, a higher total consumption of oxygen was also detected. Acetaldehyde increased during the experiment while the native anthocyanins decreased throughout the oxidation process.
Wines added with tannins featured improved color intensities with respect to the control; the addition of TT, GT and ET slightly promoted the formation of short polymeric pigments; the astringency, determined before and at the end of the experiment, decreased in all the samples, including the control wine, and mostly in the ET and GT samples.
在葡萄酒行业中，除了葡萄来源的缩合单宁外，还经常使用其他商业单宁。然而，在葡萄酒发酵后阶段，不同单宁添加物与氧吸收相关的影响尚未得到全面研究。在这项研究中，我们评估了在四个饱和循环期间四种不同商业单宁（即缩合单宁、没食子单宁、鞣花单宁和茶单宁）的影响。
向葡萄酒样品中添加四种不同的单宁类别（30 g/hL），以获得 5 个不同的实验样品：对照、没食子单宁（GT）、缩合单宁（CT）、鞣花单宁（ET）和茶单宁（TT）。四种市售单宁混合物的化学组成通过 NMR 和高分辨率质谱进行了定义。添加单宁后，每个葡萄酒样品通过空气氧化进行四个循环的饱和。在实验过程中，评估了氧消耗率（OCR）、二氧化硫消耗、乙醛生成、酚类化合物、色度特性、通过与唾液蛋白反应测定的涩味以及涩味亚品质。
实验持续了 52 天。单宁的添加影响了饱和循环的第一天的氧消耗，并且在 TT 的情况下，还检测到更高的总耗氧量。在实验过程中乙醛增加，而天然花色苷在整个氧化过程中减少。
与对照相比，添加单宁的葡萄酒具有更好的颜色强度；添加 TT、GT 和 ET 略微促进了短聚合色素的形成；在实验前后测定的涩味在所有样品中均降低，包括对照葡萄酒，并且在 ET 和 GT 样品中主要降低。
