Effect of Addition of Commercial Grape Seed Tannins on Phenolic Composition, Chromatic Characteristics, and Antioxidant Activity of Red Wine

Abstract

The effect of addition of grape seed tannins on the phenolic composition, chromatic characteristics, and antioxidant activity of red wine was studied. Two highly pure commercial grape seed tannins (GSE100 and GSE300) were selected, and their phenolic compositions were determined. Two types of red wines were made with Castelão/Tinta Miúda (3/2, w/w) grapevine varieties by fermentation on skin using two different maceration times, which correspond to the wines rich and poor in polyphenols, respectively. Each of these wines was used for experimentation with the addition of GSE100 and GSE300 before and immediately after alcoholic fermentation. Phenolic composition, chromatic characteristics, and antioxidant activity of the finished red wines were analyzed by HPLC-DAD, CIElab 76 convention, and DPPH radical test, respectively. The results showed that the addition of grape seed tannins had obvious effects of increasing color intensity and antioxidant activity only in the wines poor in polyphenols. Although GSE300 contained much higher amounts of di- and trimer procyanidins and a lower amount of polymeric proanthocyanidins, it provided effects of increasing the color intensity and antioxidant activity of the wines poor in polyphenols similar to those of GSE100. Furthermore, GSE100 released more gallic acid to wines than GSE300, although no gallic acid was detected in GSE100. Tannins added after alcoholic fermentation had a better effect on phenolic composition of red wine than tannins added before alcoholic fermentation.

Antioxidant profile of commercial oenological tannins determined by multiple chemical assays

“…The addition of oenological tannins to wine during bottle aging maintained the highest value of colour intensity and of the concentration of anthocyanins, hydroxycinnamic esters, flavonols and tannin compared with that of other winemaking procedures, such as partial running-off of the must prior to fermentation and the addition of macerating enzymes. The addition of grape seed tannins increased the antioxidant activity of wines poor in phenolic substances (Neves et al 2010), while other studies have demonstrated that the estimated antioxidant activity of musts and wines, enriched by oenological tannins, was dependent on the method applied (Baiano et al 2009). The impact of the addition of oenological tannin on wine composition has been evaluated through sensory attributes (colour, astringency, aroma and mouthfeel), the composition of phenolic substances and antioxidant capacity (Harbertson et al 2012, Versari et al 2013).…”

“…In fact, some work has shown that oenological tannins should be used with great care because depending on the characteristics of the tannin extract and its composition and concentration of phenolic substances, the addition may not improve wine composition and may even have a negative effect on it (Bautista-Ortin et al 2005, Cliff et al 2012, Harbertson et al 2012). In this context, some studies have been conducted to evaluate the effect of the addition of oenological tannins during prefermentation and postfermentation steps of winemaking and during bottle aging (Bautista-Ortin et al 2005, Parker et al 2007, Baiano et al 2009, Neves et al 2010, Gambacorta et al 2011, Canuti et al 2012). In this context, some studies have been conducted to evaluate the effect of the addition of oenological tannins during prefermentation and postfermentation steps of winemaking and during bottle aging (Bautista-Ortin et al 2005, Parker et al 2007, Baiano et al 2009, Neves et al 2010, Gambacorta et al 2011, Canuti et al 2012).…”

“…The scarce chemical information provided by suppliers (Obreque-Slíer et al 2009) and the possible variation between batches attained from natural sources (Makkar et al 1993) make it difficult to predict the impact of addition of oenological tannins on wine properties. In this context, some studies have been conducted to evaluate the effect of the addition of oenological tannins during prefermentation and postfermentation steps of winemaking and during bottle aging (Bautista-Ortin et al 2005, Parker et al 2007, Baiano et al 2009, Neves et al 2010, Gambacorta et al 2011, Canuti et al 2012). The addition of oenological tannins to wine during bottle aging maintained the highest value of colour intensity and of the concentration of anthocyanins, hydroxycinnamic esters, flavonols and tannin compared with that of other winemaking procedures, such as partial running-off of the must prior to fermentation and the addition of macerating enzymes.…”

Grape seed removal: effect on phenolics, chromatic and organoleptic characteristics of red wine

“…The reason for this decrease could be the release of gallic acid from polymeric PAs during storage as has been suggested by Nevest et al . ().…”

An industry consensus study on an HPLC fluorescence method for the determination of (±)-catechin and (±)-epicatechin in cocoa and chocolate products

“…Furthermore, a variety of HPLC detector types have been used including UV, Diode Array, Mass Spec and fluorescence [23-27]. The choice of fluorescence detection is within established analytical parameters for this determination as it offers selectivity and sensitivity for these compounds with the identity of the peaks being established by the use of authentic standards.…”