Effect of Oenotannin Addition on the Composition of Sangiovese Wines from Grapes with Different Characteristics

Abstract

Different types of oenotannins were added to Vitis vinifera cv. Sangiovese grapes of various composition and the resulting wine color parameters were measured, including intensity, hue, total phenol index, monomer anthocyanin content, and colored polymeric pigment content. Oenotannins were also tested during pre-and postfermentation on grapes harvested in 2003 from two growing areas. Grapes from the 2004 harvest were tested at different ripeness using only oenotannins exhibiting the best wine color stabilization in 2003. The response of different oenotannins varied according to grape characteristics, with gallnut and grape seed tannins most reliably stabilizing and increasing color intensity even after six months of storage. The same tannins positively affected wine color stabilization, an effect further enhanced in wine produced from less ripe grapes. Timing of oenotannin addition and grape characteristics had a significant effect on color intensity and stabilization. The estimation of grape phenolic maturity may allow for improved wine color characteristics by tailoring the use of oenotannins.

Effect of the addition of different types of oenological commercial tannins on phenolic and sensorial red wine characteristics evolution

“…Regarding to non-flavonoid phenols evolution it was not possible to detected a clear influence of the use of different oenological tannins. Our results are consistent with previous reports [2,3,14]. However, according to Canuti et al [3], timing of oenological tannins addition and grape characteristics had a significant effect on phenolic parameters results.…”

“…Our results are consistent with previous reports [2,3,14]. However, according to Canuti et al [3], timing of oenological tannins addition and grape characteristics had a significant effect on phenolic parameters results. For these authors, oenological tannins addition during pre-fermentation had also a more significant influence on phenolic parameters than did addition during post-fermentation.…”

“…Wines codes legend see Table 1; (2) values expressed as gallic acid equivalents; (3) values expressed as malvidin-3-monoglucoside equivalents; data points derived for each aging day and phenolic parameter showing the same letter are not significantly different (Tukey, p < 0.05); ± standard deviation. was particularly detected after 20 aging days, especially in wines with oenological tannins containing condensed tannins (TPA and TPB wines) and one of the hydrolyzable tannin used (TEB wine).…”

“…However, while many winemakers have practical experience with commercial oenological tannins addition and tannin suppliers report color enhancement, oxidative protection, flavor and mouthfeel improvements as a consequence of addition of oenological tannins, there are several experimental works that reported contradictory results about the potential benefits of these products. Thus, some authors [2,3,5] reported several evidences of the benefits to wine color from tannin preparations added during red wine vinification and aging while other authors [6,7] reported that they may not always improve the wine characteristics or has a little effect. In addition, it is important to note that the majority of the studies analyze the addition of oenological tannins during the prefermentation and not after the malolactic fermentation and also don't make an evaluation of the wine during a long aging period.…”

“…According to several authors [2][3][4], there are numerous positive effects by the use of oenological tannins, namely in wine color stabilization, wine structure a e-mail: antoniojordao@esav.ipv.pt improvement, laccase activity, and elimination of reductive odors. However, while many winemakers have practical experience with commercial oenological tannins addition and tannin suppliers report color enhancement, oxidative protection, flavor and mouthfeel improvements as a consequence of addition of oenological tannins, there are several experimental works that reported contradictory results about the potential benefits of these products.…”