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Effect of Wine Production Techniques on Wine Resveratrol and Total Phenolics
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Effect of Wine Production Techniques on Wine Resveratrol and Total Phenolics Jelena Cvejić, Milica Atanacković Department of Pharmacy, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
also to their sensory characteristics, such as color, flavor, and astringency. Total phenolic content of red wines usually range from 900 to 2500 mg/l gallic acid equivalents (GAE) and can reach up to 6000 mg/l GAE (Cimino et al., 2007; Woraratphoka et al., 2007). Resveratrol is a stilbene produced by grapevines, primarily located in grape skin and usually present in red wine. Numerous biological activities of this compound have been demonstrated (Frémont, 2000). The naturally occurring form of resveratrol in grape is the trans-isomer. Also, it exists as the cis-isomer as well as resveratrolglucoside (Figure 60.1). It is considered that red wine on average contains 1.9 mg/l of trans-resveratrol ranging from non-detectable up to 14.3 mg/l. Concentrations of cis-resveratrol are in general lower and can reach 5 mg/l (Sterbvo et al., 2007). During the winemaking process, phenolic compounds are partially transferred from grapes to must and to wine. The final composition of phenolic compounds in wine depends on grape variety and maturity, environmental factors, extraction parameters, winemaking technology, as well as chemical reactions that occur during wine aging (Paixao et al., 2007). Wine phenolics, mostly resveratrol, have been widely studied in many different publications. However, factors influencing their content are not investigated to any great extent.
CHAPTER POINTS • R esveratrol and phenolics contribute to the beneficial effects of moderate wine consumption on human health. • Various factors influence the content of resveratrol and phenolics in wine. • Winemaking procedures have diverse effects on the content of biologically active compounds. • Factors increasing resveratrol and total phenolic content in wine include fermentation temperature, thermovinification, extended maceration, must freezing, and pectolytic enzymes addition. • Processes influencing phenolic content include yeast selection, runoff process, carbonic maceration, cold-soak treatment, and sulfur dioxide level. • Understanding of factors influencing preservation of resveratrol and total phenolic content is essential for increasing health benefits and nutritional properties of wine.
INTRODUCTION The beneficial effects of wine on human health, mainly resulting from phenolic compounds, are well known. Among them, resveratrol has been studied most extensively (trans-3,5,4′-trihydroxystilbene). These compounds (phenolic acids, stilbenes, flavanols, flavonols, anthocyanins, etc.) have potential protective effects on diseases mediated by oxidation including coronary diseases, inflammation, and cancer (Cimino et al., 2007; Soleas et al., 1997). Phenolics present in wine contribute
Processing and Impact on Active Components in Food http://dx.doi.org/10.1016/B978-0-12-404699-3.00060-3
HOW COMPOSITION IS ALTERED Effects of Winemaking Technologies on Resveratrol Content Being a compound with a numerous potential biological activities, resveratrol could contribute to the beneficial and health-promoting properties of wine. Therefore, elucidation of specific factors influencing the amount of
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FIGURE 60.1 Structures of resveratrol and its forms: (a) trans-resveratrol; (b) cisresveratrol; (c) trans-resveratrol glucoside (trans-piceid); (d) cis-resveratrol glucoside (cis-piceid).
this compound in wine is important. Resveratrol content in wine depends on different factors (variety, harvest year, climatic conditions, UV light, etc.), and winemaking technology is one among them that can be controlled. The most important results concerning this subject are summarized in Table 60.1. Maceration Time Generally, it is well established that prolonged maceration time and higher ethanol content positively affect the extraction of resveratrol and piceid, which is due to their better solubility. A previously published study analyzed the application of different maceration times (3, 6, and 10 days) on resveratrol and piceid content. The highest concentrations of resveratrol and piceid were observed in wines produced with 10 days of maceration. Conversely, wines with relatively low contents of these compounds reached maximal concentrations after shorter periods of time. This could be due to enzymatic cleavage of the glycosidic bond of piceid as well as the possibility of metabolism of resveratrol by yeasts (Kostadinović et al., 2012). The same authors observed that longer maceration time increased the antioxidant activity of wines, which could be due to higher content of other phenolics. Short contact of skin and seeds, which involves lower ethanol concentration, results in an incomplete extraction of phenolic compounds. In another study, prolonged maceration increased resveratrol content in wines made from Cabernet Sauvignon, while the opposite effect (decrease of
resveratrol content) was observed in varieties Cynthiana and Noble (Threllfall et al., 1999). Moreover, the study conducted by Sun et al. (2003) showed that prolonged maceration did not affect concentration of resveratrol in wines made from the Castelao variety. These results suggest that the influence of maceration time could vary depending on the grape cultivar used. Resveratrol concentration can increase during fermentation on the skins, but it is important to emphasize that the final concentration of this compound in wine depends also on the grape variety as well as on enological conditions. Thermovinification Thermovinification is a process that requires intact or crushed grape (usually for the red-wine-making process) to be heated (50°C to 87°C) for a short time (Clarke and Bakker, 2004). Atanacković et al. (2012) analyzed the influence of two different thermovinification methods (60°C for 30 min and 80°C for 3 min) on resveratrol content in four different grape varieties (Merlot, Cabernet Sauvignon, Pinot Noir, and Prokupac). The results demonstrated that resveratrol content depends mainly on the grape variety. However, compared with control samples, applied processes increased resveratrol content only in the Pinot Noir variety. In another study, Netzel et al. (2003) showed that this procedure increases total resveratrol content in wines made from Pinot Noir, Lemberger, and Cabernet Franc, probably due to better extraction.
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How Composition is Altered
TABLE 60.1 Effects of Winemaking Technologies on Resveratrol Content in Wine—An Overview Reference
Experiment
Analyzed Parameter Effect
Comment
Netzel et al. (2003)
Fermentation on skin Mash heating (65°C) Combination of both
Trans- and cisresveratrol Trans/cis piceid
Combination of heating with skin fermentation increased total resveratrol up to 400% times
Applied procedure also increased antioxidant activity and some other phenolics content (anthocyanins, flavan-3-ols and flavonols)
Sun et al. (2003)
Carbonic maceration Skin fermentation with/without stems
Trans- and cisresveratrol
Augmentation of resveratrol content after skin fermentation comparing to carbonic maceration; no influence of stems
Prolonged maceration has no influence on resveratrol content
Atanacković et al. (2012)
Thermovinification 60°C for 30 min, 80°C for 3 min
Trans- and cisresveratrol
Increase of trans-resveratrol up to 40% for Pinot Noir variety
Significant influence of grape variety on resveratrol content
Trans-resveratrol Trans-piceid
Maximal concentrations detected after 10 days in comparison with 3-day maceration piceid increased100%, resveratrol nearly 600% increased
Duration of maceration time had strong influence on antioxidative activity
Trans-resveratrol Trans-piceid
Piceid concentrations 100% higher with French yeast Resveratrol concentrations up to 400%
Wines produced with Macedonian yeast had higher antioxidative activity than those with French yeast
Kostadinović et al. (2012) Duration of maceration (3, 6, 10 days), Merlot wine
French and Macedonian yeast, Merlot and Vranec wines
The table shows effects produced by variation of different parameters (e.g., temperature and duration of fermentation) during wine production on resveratrol concentration.
These findings suggest that thermovinification could be responsible for the enhancement of concentration of resveratrol in wine, but this effect, as shown in some studies, may also differ according to grape variety. Yeast selection Another important factor, which can significantly influence resveratrol content in wine, is yeast selection. However, only a few published reports address this topic. Vacca et al. (1997) showed that yeasts used for fermentation of must are among the factors responsible for the decrease of resveratrol content in wines. This was explained by the absorption of the compound on cell walls or absorption/metabolism by the yeast cells. The fact that different yeast types could influence resveratrol content was also confirmed by Kostadinović et al. (2012). The authors noticed an increase of resveratrol (up to four times) and piceid (up to two times) in Merlot wines produced using French yeast when compared with Macedonian yeast. It was observed (authors’ unpublished data) that when compared with spontaneous fermentation, addition of selected yeasts could result in an augmentation as well as a decrease of resveratrol content, depending on yeast variety and properties.
In addition, it has been established that yeasts’ β-glucosidase activity depends on maceration time (Vrhovsek et al., 1997), thus the final content of resveratrol and piceid is a result of yeast selection as well as maceration period. Addition of β-glucosidase from Aspergillus niger in Sicilian wines increased the transresveratrol content up to 75% (Todaro et al., 2008).
Effects of Winemaking Technologies on Total Phenolic Content It is well known that phenolic compounds present in wine can show a beneficial effect on human health. Therefore, clarification of the influence of different enological practices on phenolic level in wine is essential and this topic has been addressed for many years in scientific publications. The main results from selected publications focused on this topic are summarized in Table 60.2. Fermentation Temperature There are several published reports that confirm that higher fermentation temperatures increase phenolic extraction in wine. As far as the authors are aware, Ough and Amerine (1961) published the first observation
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TABLE 60.2 Effects of Winemaking Technologies on Total Phenolic Content in Wine—An Overview Reference
Experiment
Analyzed Parameter
Effect
Comment
Timberlake and Bridle (1976)
Fermentation on the skins Thermovinification (60°C, 30 min, then 45°C, 30 min) Carbonic maceration
Total phenolics (TP)
Carbonic maceration wine almost 20% higher TP than thermovinificated wine
Thermovinificated wine was much more colored
Girard et al. (2001)
Cold fermentation 15°C Ambient fermentation 20°C High temperature 30°C Modified cold fermentation 15°C
Total phenolics (TP)
High temperature of fermentation lead to almost 50% increase in total phenolics compared with modified cold fermentation
Higher fermentation temperature; increase permeability of the hypodermal cell; releasing anthocyanin; increased solubility of other phenolics in the wine solution
Different vinification yeasts Saccharomyces bayanus Saccharomyces cerevisiae
Total phenolics (TP)
For modified cold fermentation S. cerevisiae increased TP by 50%
Spranger et al. (2004)
Skin fermentation with stems (7, 21 days) 25°C Skin fermentation without stems (7 days) 25°C Carbonic maceration 35°C (21 days)
Total phenolic index (TP) Total anthocyanins (TA)
Duration had no significant influence Carbonic maceration wines significantly lower TA and TP than skin contact (average 20% lower for TP and 50 % lower for TA) Stem contact slightly increased TP
Although higher temperature may induce degradation-condensation of anthocyanins, it favors diffusion of other phenols during carbonic maceration
Atanacković et al. (2012)
Thermovinification 60°C for 30 min, 80°C for 3 min
Total phenolics (TP)
Increased total phenolic content in all thermovinificated samples (up to 100%)
Only for Pinot Noir, higher temperature (80°C) produced more phenolic compounds in wine Increased total phenolic lead to increased antioxidative activity of wine samples
The table shows effects produced by variation of different parameters (e.g., thermovinification, temperature, and yeast selection) during wine production on total phenolic content.
of fermentation temperature influence on phenolic content. It was noticed that the color of wines produced from Pinot Noir and Cabernet Sauvignon was more intense as the fermentation temperature increased. Some later reports for Pinot Noir confirmed that increasing temperature from 15 to 30°C significantly increases total phenolic content in wine (Girard et al., 2001). In another report by Spranger et al. (2004), it was observed that increased temperature (35°C) during carbonic maceration induces degradation or condensation of anthocyanins, but it can favor improved diffusion of other polyphenols from grape to wine and increase total phenolic content. Thermovinification After heating of intact or crushed grapes during thermovinification process, the grapes are pressed and must is inoculated with yeast strain for fermentation. Before fermentation, grape skins and seeds could be removed from must or left in during this process. Atanacković
et al. (2012) examined total phenolic content in wines made by two different thermovinification methods (Table 60.2) from four grape varieties (Merlot, Cabernet Sauvignon, Pinot Noir, and Prokupac). It was observed that increased temperature lead to higher phenolic content in all cultivars and accordingly increased antioxidative capacity of wine samples. Netzel et al. (2003) observed that heating of must (skins with liquid) results in higher concentration of anthocyanins, flavan-3-ols and flavonols in Pinot Noir, Lemberger, and Cabernet Franc varieties. Conversely, some other previously published results reported that thermovinification leads to improved color extraction (anthocyanins), but much lower total phenolic extraction (Auw et al., 1996). A similar trend was also observed for some Italian grape varieties (Stella et al., 1991). It is generally recognized that heat treatment can be effective in increased phenolic extraction if it is applied on must (containing grape skins and seeds) (Sacchi et al., 2005).
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Other Ways in Which Composition is Altered
Carbonic Maceration During carbonic maceration, whole berries and clusters are held under a carbon dioxide atmosphere and partial fermentation occurs because of the activity of glycolytic enzymes present in grapes (Flanzy, 1935). In order to complete fermentation, after 1–2 weeks, the grapes are pressed and the juice is inoculated. Timberlake and Bridle (1976) found that wines produced by carbonic maceration contained the highest amount of phenolic compounds and less anthocyanin and polymeric pigments when compared with wines made by thermovinification and fermentation on the skin. Similar results were obtained by Sun et al. (2001). Conversely, the study by Spranger et al. (2004) showed that carbonic maceration of Castelao wines resulted in the lowest phenolic as well as anthocyanin content. A study by Pellegrini et al. (2000) confirmed that the influence of carbonic maceration on total phenolics depends on grape variety. Maceration Time Extended maceration prolongs skin contact and the hypothesis that this process could increase extraction of phenolic compounds is supported by current literature. It has been shown that longer pomace contact increased the concentration of anthocyanins and tannins (10 versus 4 or 5 days). Also, aging in the bottle (1 year) of wine produced by longer pomace contact results in higher content of polymeric pigments (Gomez-Plaza et al., 2001). Prolonged maceration time for Merlot wines lead to an increase of total phenols up to 36 days, while pigments increased up to day 4, and then slowly decreased (Yokotsuka et al., 2000). On the contrary, another study did not reveal any significant difference between total phenols within 7 and 21 days’ skin fermented wine. Moreover, a decrease in anthocyanins was observed, probably because of their absorption on yeast or/and condensation and degradation (Spranger et al. 2004). Yeast There are a few published studies pertaining to the effect of yeast on phenolic content in wine. Obtained results showed that selected yeast could produce variable effects depending mainly on the grape variety studied. It has been observed that, applied to the same variety, differences could be obtained according to yeast strain (Cuinier, 1997; authors’ unpublished data). However, in some studies no major differences were observed in phenolic content as regards the use of different yeast. Zini et al. (2003) showed that application of three yeast strains on one variety gave similar phenolic content. Likewise, significant differences were not observed when comparing phenolic content in wines obtained from four grape varieties using five yeast strains (Nicolini et al., 2003).
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OTHER WAYS IN WHICH COMPOSITION IS ALTERED Other factors affecting phenolic content during the wine-making process were also investigated. Besides those previously mentioned, the factors that could have a positive effect on the increase of biologically active compounds in wine (when applied during wine making) are summarized below. Freezing the must before fermentation could influence the content of phenolics in wine. This process breaks cell membranes and thus can increase the extraction of anthocyanins and tannins. This was confirmed by Couasnon (1999), who observed a 50% increase in anthocyanins and tannins in three grape varieties (Merlot, Cabernet Sauvignon, and Cabernet Franc). Conversely, freezing the pomace separated from the juice resulted in a slight increase of anthocyanins, while the impact on total phenolic compounds varied. Low-temperature extraction in the absence of alcohol (cold soak) produced little difference in phenolic content. It has been shown that this process generally has negative or no effects (decrease of anthocyanins and flavonols) on phenolics. However, when combined with addition of sulfur dioxide, the increase of total phenolics and anthocyanins is pronounced (Gerbaux, 1993). Prefermentation juice run-off is a process aimed at increasing skin to juice ratio by removing juice before fermentation. The procedure is expected to increase concentration of phenolics from skins and seeds in wine. This was supported by the results obtained by Zamora et al. (1994) where increases in flavonoid and anthocyanin concentrations was observed when 10% juice was removed. An increase in phenolic content was also observed after applying the run-off technique by Gerbaux (1993). However, some studies showed different results. It has been noticed that 30% and 50% juice run-off (30% and 50% removal) results in variable effects on phenolic content in wines from different grape varieties (Atanacković et al., 2012). Inconsistent results after 10% and 20% juice removal were observed also by Gawel et al. (2001). It could be partially explained by solubility limitation, since there is less liquid for dissolution of targeted compounds. Addition of pectolytic enzymes can increase total phenols as well as wine color intensity. It has been demonstrated that pectinases improve extraction of phenolics (Daudt and Polenta 1999). In most cases, applied enzymes do not increase anthocyanis, but can increase the amount of other phenolic compounds (e.g., tannins). Additionally, it has been reported that higher sulfur dioxide levels can produce enlargement of pigment extraction during early fermentation, but final concentration of pigments as well as total phenolics in wines were not significantly higher (Bakker et al., 1998).
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Application of increased fermentation temperature, thermovinification, must freezing, and extended maceration during the wine-making process have been reported to increase phenolic content in wine. Conversely, other investigated factors, such as sulfur dioxide levels and cold-soak treatments have frequently been shown to have little or no lasting effects, or to lead to a decrease in phenolic levels.
ANALYTICAL TECHNIQUES Siemann and Creasy (1992) conducted the first analysis of resveratrol content in wine. The described HPLC analytical method included a complex extraction procedure and large sample volumes. Nowadays, numerous studies are focused on this topic. In the last 20 years, interest in resveratrol and quantification of this compound in different samples has rapidly increased, and a number of publications covering this topic have been published. The most commonly used method for adequate determination of all resveratrol forms is HPLC analysis. Some of the techniques applied are listed in Table 60.3. Successful identification and quantification of both resveratrol isomers (trans-, cis-) has been reported (Atanacković et al., 2012) as well as other resveratrol forms (piceid, resveratrol-glucuronide, etc.) (Soleas et al., 1997; Kostadinović et al., 2012). Reference standards for transresveratrol and trans-piceid are commercially available,
while corresponding cis-forms are usually obtained after in situ UV light exposure of trans-isomer solution (Cvejić et al., 2010; Netzel et al., 2003; Sun et al., 2003). The methods used could require sample preparation, as frequently used solid-phase extraction or classic liquid/ liquid extraction (Sun et al., 2003). Conversely, the increasingly used direct injection of wine samples has also been shown to provide satisfactory results (Netzel et al., 2003). There is a variety of detection methods for resveratrol determination using liquid chromatography. Most commonly used method is UV/DAD detection performed with or without sample preparation. Detection wavelengths are usually near the absorption maximum of investigated compounds (around 305 nm and 280 nm for trans- and cis-resveratrol, respectively). In addition, due to the physico-chemical properties of resveratrol, use of the fluorescent detector (FLD) is possible. This type of highly sensitive detection could allow measurement of small quantities of resveratrol (Atanacković et al., 2012). Also, a more specific mode of detection comparing to UV/DAD, FLD could be easily used for resveratrol quantification from a complex matrix such as wine, without any sample preparation. Mass spectrometry (MS) detection has been coupled with HPLC for reliable confirmation of resveratrol isomers and metabolites in different samples (Kostadinović et al., 2012). The most commonly used stationary phase for HPLC analysis of resveratrol is easily available octadecil reverse phase. Mobile phases applied for successful separation
TABLE 60.3 Analytical Procedures for Identification and Quantification of Resveratrol Reference
Analyte
Sample Preparation
Method
Conditions
Detection
Threlfall et al. (1999)
Trans-resveratrol
Quantification by standard addition method
HPLC Phenomenex bondclone phenyl column
Gradient elution Methanol/water pH 2.5
UV 310 nm
Netzel et al. (2003)
Trans-resveratrol Trans-piceid
Direct injection
HPLC RP C18 column
Gradient elution Acetonitrile/water/ formic acid
UV/DAD 310 nm
Sun et al. (2003)
TransCisresveratrol
SPE Liquid/liquid extraction
HPLC RP C18 column
Gradient elution Acetonitrile/water
UV 307 nm trans 285 nm cis
Todaro et al. (2008)
TransCisresveratrol
Liquid/liquid extraction
HPLC RP C18 column
Gradient elution Acetonitrile/ phosphoric acid
UV/DAD Wavelength not specified
Atanacković et al. (2012)
TransCisresveratrol
Direct injection
HPLC RP C18 column
Gradient elution Methanol/water/ formic acid
FLD Ex330 Em374 trans UV/DAD 280 nm cis
Kostadinović et al. (2012)
Trans-resveratrol Trans-piceid
Direct injection
HPLC RP C18 column
Gradient elution Acetonitrile/acetic acid/water
MS
The table shows the most commonly used analytical procedures for determination of resveratrol isomers in wine. HPLC, high-performance liquid chromatography; RP, reverse phase; C18, octadecyl bonded silica; UV/DAD, ultraviolet diode array detection; FLD, fluorescence detection.
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References
could vary, but consist mainly of a combination of frequently used solvents for HPLC analysis such as methanol, ethanol, acetonitrile, formic acid, and water. Another approach for resveratrol determination, which is not as frequently used as HPLC, is application of gas chromatography coupled with mass spectroscopy. Sample preparation includes solid-phase extraction or liquid extraction after which trimethylsylil resveratrol derivates are formed. The total phenolic amount is commonly determined with UV/Vis spectroscopy by applying Folin–Ciocalteu’s reaction. The results are expressed either as total phenolic index (Sun et al., 2001) or more frequently, as gallic acid equivalents in 1 l of wine (mg/l GAE) (Atanacković et al., 2012; Woraratphoka et al., 2007). Since antioxidative capacity is closely related to total phenolic content of wine, it is very often included in studies concerning phenolic content. It is usually estimated by DPPH (Atanacković et al., 2012) or TEAC tests (Netzel et al., 2003; Kostadinović et al., 2012). The individual phenolic compounds most abundant in wine (e.g., catehin, gallic acid, quercetin, etc.) are usually successfully identified and quantified with HPLC analysis using DAD. Nevertheless, analysis of different factors, which influence individual phenolic compounds in wine, is not extensively described in the literature. With respect to the importance of these natural compounds and their assumed health benefits, this subject is currently expanding.
References Atanacković, M., Petrović, A., Jović, S., Gojković-Bukarica, Lj., Bursać, M., Cvejić, J., 2012. Influence of winemaking technique on the resveratrol content, total phenolic content and antioxidant potential of red wines. Food Chem. 131 (2), 513–518. Auw, J.M., Blanco, V., O’Keefe, S.F., Sims, C.A., 1996. Effect of processing on the phenolics and color of Cabernet Sauvignon, Chambourcin, and Noble wines and juices. Am. J. Enol. Vitic. 47, 279–286. Bakker, J., Bridle, P., Bellworthy, S.J., Garcia-Viguera, C., Reader, H.P., Watkins, S.J., 1998. Effect of sulphur dioxide and must extraction on colour, phenolic composition and sensory quality of red table wine. J. Sci. Food Agric. 78, 297–307. Cimino, F., Sulfaro, V., Trombetta, D., Saija, A., Tomaino, A., 2007. Radical-scavenging capacity of several Italian red wines. Food Chem. 103, 75–81. Clarke, R.J., Bakker, J., 2004. Wine-Flavour Chemistry. Blackwell Publishing Ltd., Oxford. Couasnon, M.B., 1999. Une nouvelle technique: La maceration préfermentaire à froid-extraction à la neige carbonique. Premièr partie: Résultats oenologiques. Rev. Oenol. 92, 26–30. Cuinier, C., 1997. Ceppi di lievito e composizione fenolica dei vini rossi. Vignevini 7/8, 39–42. Cvejic, J.M., Djekic, S.V., Petrovic, A.V., Atanackovic, M.T., Jovic, S.M., Brceski, I.D., Gojkovic–Bukarica, Lj.C., 2010. Determination of trans- and cis-resveratrol in Serbian commercial wines. J. Chromatogr. Sci. 48, 229–234. Daudt, C.E., Polenta, G.A., 1999. Les phénols dans les moûts de Cabernet Sauvignon et d’Isabel soumis à divers traitements. J. Sci. Tech. Tonnellerie 5, 47–55.
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Flanzy, M., 1935. Nouvelle méthode de vinification. C.R. Acad. Agric. Fr. 21, 935–938. Frémont, L., 2000. Biological effects of resveratrol. Life Sci. 66 (8), 663–673. Gawel, R., Iland, P.G., Leske, P.A., Dunn, C.G., 2001. Compositional and sensory differences in Syrah wines following juice run-off prior to fermentation. J. Wine Res. 12, 5–18. Gerbaux, V., 1993. Etude de quelques conditions de cuvaison susceptibles d’augmenter la composition polyphénolique des vins de Pinot noir. Rev. Oenol. 69, 15–18. Girard, B., Yuksel, D., Cliff, M.A., Delaquis, P., Reynolds, A.G., 2001. Vinification effects on the sensory, colour, and GC profiles of Pinot noir wines from British Colombia. Food Res. Int. 34, 483–499. Gómez-Plaza, E., Gil-Muñoz, R., López-Roca, J.M., Martínez-Cutillas, A., Fernández-Fernández, J.I., 2001. Phenolic compounds and color stability of red wines: Effect of skin maceration time. Am. J. Enol. Vitic. 52, 266–270. Kostadinović, S., Wilkens, A., Stefova, M., Ivanova, V., Vojnovski, B., Mirhosseini, H., Winterhalter, P., 2012. Stilbene levels and antioxidant activity of Vranec and Merlot wines from Macedonia: Effect of variety and enological practices. Food Chem. 135, 3003–3009. Lopez-Velez, M., Martinez-Martinez, F., Del Valle-Ribes, C., 2003. The study of phenolic compounds as natural antioxidants in wine. Crit. Rev. Food Sci. Nutr. 43 (3), 233–244. Nicolini, G., Mattivi, F., Larcher, R., Volpini, A., 2003. Vinificazioni in rosato ed in rosso con lieviti selezionati: observazioni circa il colore. Enologo 39, 79–83. Ough, C.S., Amerine, M.A., 1961. Studies on controlled fermentation.V. Effects on color, composition, and quality of red wines. Am. J. Enol. Vitic. 12, 9–19. Paixao, N., Perestrelo, R., Marques, J.C., Camara, J.S., 2007. Relationship between antioxidant capacity and total phenolic content of red, rose´ and white wines. Food Chem. 105, 204–214. Pellegrini, N., Simonetti, P., Gardana, C., Brenna, O., Brighenti, F., Pietta, P., 2000. Polyphenol content and total antioxidant activity of vini novelli (young red wines). J. Agric. Food Chem. 48, 732–735. Sacchi, K.L., Bisson, L.F., Adams, D.O., 2005. A Review of the Effect of Winemaking Techniques on Phenolic Extraction in Red Wines. Am. J. Enol. Vitic. 56 (3), 197–206. Siemann, E.H., Creasy, L.L., 1992. Concentration of the Phytoalexin Resveratrol in Wine. Am. J. Enol. Vitic. 43 (1), 49–52. Soleas, G., Diamandis, E.P., Goldberg, D.M., 1997. Resveratrol: A molecule whose time has come? And gone? Clin. Biochem. 30, 91–113. Spranger, M.I., Climaco, M.C., Sun, B., Eiriz, N., Fortunato, C., Adelina, N., Leandro, M.C., Avelar, L., Belchior, A.P., 2004. Differentiation of red winemaking technologies by phenolic and volatile composition. Anal. Chim. Acta 513, 151–161. Stella, C., Testa, F., Viviani, C., Sabatelli, M.P., 1991. Trattamento a caldo delle uve: influenza su vini da vitigni diversi. Vignevini 12, 47–50. Stervbo, U., Vang, O., Bonnesen, C., 2007. A review of the content of the putative chemopreventive phytoalexin resveratrol in red wine. Food Chem. 101, 449–457. Sun, B., Ferrao, C., Spranger, M.I., 2003. Effect of wine style and winemaking technology on resveratrol levels in wines. Cienc. Tec. Vitivinic. 18 (2), 77–91. Sun, B., Spranger, I., Roque-do Vale, F., Leandro, C., Belchior, P., 2001. Effect of Different Winemaking Technologies on Phenolic Composition in Tinta Miúda Red Wines. J. Agric. Food Chem. 49, 5809–5816. Threlfall, R.T., Morris, J.R., Mauromoustakos, A., 1999. Effect of Variety, Ultraviolet Light Exposure, and Enological Methods on the transResveratrol Level of Wine. Am. J. Enol. Vitic. 50 (1), 57–64. Timberlake, C.F., Bridle, P., 1976. The effect of processing and other factors on the colour characteristics of some red wines. Vitis 15, 37–49. Todaro, A., Palmeri, R., Barbagallo, R.N., Pifferi, P.G., Spagna, G., 2008. Increase of trans-resveratrol in typical Sicilian wine using b-Glucosidase from various sources. Food Chem. 107, 1570–1575.
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Vacca, V., Leccis, L., Fenu, P., Pretti, L., Farris, G.A., 1997. Wine yeasts and resveratrol content. Biotechnol. Lett. 19 (6), 497–498. Vrhovsek, U., Wendelin, S., Eder, R., 1997. Effects of various vinification techniques on the concentration of cis and trans resveratrol and resveratrol glucoside isomers in wine. Am. J. Enol. Vitic. 48, 214–219. Woraratphoka, J., Intarapichet, K.O., Indrapichate, K., 2007. Phenolic compounds and antioxidative properties of selected wines from the northeast of Thailand. Food Chem. 104, 1485–1490.
Yokotsuka, K., Sato, M., Ueno, N., Singleton, V.L., 2000. Colour and sensory characteristics of Merlot red wines caused by prolonged pomace contact. J. Wine Res. 11, 7–18. Zamora, F., Luengo, G., Margalef, P., Magriña, M., Arola, L., 1994. Nota. Efecto del sangrado sobre el color y la composición en compuestos fenólicos del vino tinto. Rev. Esp. Cienc. Tecnol. Aliment. 34, 663–671. Zini, S., Canuti, V., Siliani, A., Bertuccioli, M., 2003. Criomacerazione in Toscana: Esperienze sul Sangiovese. Ind. Bevande 32, 16–23.
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Effect of Wine Production Techniques on Wine Resveratrol and Total Phenolics Jelena Cvejić, Milica Atanacković Department of Pharmacy, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
also to their sensory characteristics, such as color, flavor, and astringency. Total phenolic content of red wines usually range from 900 to 2500 mg/l gallic acid equivalents (GAE) and can reach up to 6000 mg/l GAE (Cimino et al., 2007; Woraratphoka et al., 2007). Resveratrol is a stilbene produced by grapevines, primarily located in grape skin and usually present in red wine. Numerous biological activities of this compound have been demonstrated (Frémont, 2000). The naturally occurring form of resveratrol in grape is the trans-isomer. Also, it exists as the cis-isomer as well as resveratrolglucoside (Figure 60.1). It is considered that red wine on average contains 1.9 mg/l of trans-resveratrol ranging from non-detectable up to 14.3 mg/l. Concentrations of cis-resveratrol are in general lower and can reach 5 mg/l (Sterbvo et al., 2007). During the winemaking process, phenolic compounds are partially transferred from grapes to must and to wine. The final composition of phenolic compounds in wine depends on grape variety and maturity, environmental factors, extraction parameters, winemaking technology, as well as chemical reactions that occur during wine aging (Paixao et al., 2007). Wine phenolics, mostly resveratrol, have been widely studied in many different publications. However, factors influencing their content are not investigated to any great extent.
CHAPTER POINTS • R esveratrol and phenolics contribute to the beneficial effects of moderate wine consumption on human health. • Various factors influence the content of resveratrol and phenolics in wine. • Winemaking procedures have diverse effects on the content of biologically active compounds. • Factors increasing resveratrol and total phenolic content in wine include fermentation temperature, thermovinification, extended maceration, must freezing, and pectolytic enzymes addition. • Processes influencing phenolic content include yeast selection, runoff process, carbonic maceration, cold-soak treatment, and sulfur dioxide level. • Understanding of factors influencing preservation of resveratrol and total phenolic content is essential for increasing health benefits and nutritional properties of wine.
INTRODUCTION The beneficial effects of wine on human health, mainly resulting from phenolic compounds, are well known. Among them, resveratrol has been studied most extensively (trans-3,5,4′-trihydroxystilbene). These compounds (phenolic acids, stilbenes, flavanols, flavonols, anthocyanins, etc.) have potential protective effects on diseases mediated by oxidation including coronary diseases, inflammation, and cancer (Cimino et al., 2007; Soleas et al., 1997). Phenolics present in wine contribute
Processing and Impact on Active Components in Food http://dx.doi.org/10.1016/B978-0-12-404699-3.00060-3
HOW COMPOSITION IS ALTERED Effects of Winemaking Technologies on Resveratrol Content Being a compound with a numerous potential biological activities, resveratrol could contribute to the beneficial and health-promoting properties of wine. Therefore, elucidation of specific factors influencing the amount of
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60. FACTORS INFLUENCING WINE PHENOLICS, RESVERATROL
FIGURE 60.1 Structures of resveratrol and its forms: (a) trans-resveratrol; (b) cisresveratrol; (c) trans-resveratrol glucoside (trans-piceid); (d) cis-resveratrol glucoside (cis-piceid).
this compound in wine is important. Resveratrol content in wine depends on different factors (variety, harvest year, climatic conditions, UV light, etc.), and winemaking technology is one among them that can be controlled. The most important results concerning this subject are summarized in Table 60.1. Maceration Time Generally, it is well established that prolonged maceration time and higher ethanol content positively affect the extraction of resveratrol and piceid, which is due to their better solubility. A previously published study analyzed the application of different maceration times (3, 6, and 10 days) on resveratrol and piceid content. The highest concentrations of resveratrol and piceid were observed in wines produced with 10 days of maceration. Conversely, wines with relatively low contents of these compounds reached maximal concentrations after shorter periods of time. This could be due to enzymatic cleavage of the glycosidic bond of piceid as well as the possibility of metabolism of resveratrol by yeasts (Kostadinović et al., 2012). The same authors observed that longer maceration time increased the antioxidant activity of wines, which could be due to higher content of other phenolics. Short contact of skin and seeds, which involves lower ethanol concentration, results in an incomplete extraction of phenolic compounds. In another study, prolonged maceration increased resveratrol content in wines made from Cabernet Sauvignon, while the opposite effect (decrease of
resveratrol content) was observed in varieties Cynthiana and Noble (Threllfall et al., 1999). Moreover, the study conducted by Sun et al. (2003) showed that prolonged maceration did not affect concentration of resveratrol in wines made from the Castelao variety. These results suggest that the influence of maceration time could vary depending on the grape cultivar used. Resveratrol concentration can increase during fermentation on the skins, but it is important to emphasize that the final concentration of this compound in wine depends also on the grape variety as well as on enological conditions. Thermovinification Thermovinification is a process that requires intact or crushed grape (usually for the red-wine-making process) to be heated (50°C to 87°C) for a short time (Clarke and Bakker, 2004). Atanacković et al. (2012) analyzed the influence of two different thermovinification methods (60°C for 30 min and 80°C for 3 min) on resveratrol content in four different grape varieties (Merlot, Cabernet Sauvignon, Pinot Noir, and Prokupac). The results demonstrated that resveratrol content depends mainly on the grape variety. However, compared with control samples, applied processes increased resveratrol content only in the Pinot Noir variety. In another study, Netzel et al. (2003) showed that this procedure increases total resveratrol content in wines made from Pinot Noir, Lemberger, and Cabernet Franc, probably due to better extraction.
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How Composition is Altered
TABLE 60.1 Effects of Winemaking Technologies on Resveratrol Content in Wine—An Overview Reference
Experiment
Analyzed Parameter Effect
Comment
Netzel et al. (2003)
Fermentation on skin Mash heating (65°C) Combination of both
Trans- and cisresveratrol Trans/cis piceid
Combination of heating with skin fermentation increased total resveratrol up to 400% times
Applied procedure also increased antioxidant activity and some other phenolics content (anthocyanins, flavan-3-ols and flavonols)
Sun et al. (2003)
Carbonic maceration Skin fermentation with/without stems
Trans- and cisresveratrol
Augmentation of resveratrol content after skin fermentation comparing to carbonic maceration; no influence of stems
Prolonged maceration has no influence on resveratrol content
Atanacković et al. (2012)
Thermovinification 60°C for 30 min, 80°C for 3 min
Trans- and cisresveratrol
Increase of trans-resveratrol up to 40% for Pinot Noir variety
Significant influence of grape variety on resveratrol content
Trans-resveratrol Trans-piceid
Maximal concentrations detected after 10 days in comparison with 3-day maceration piceid increased100%, resveratrol nearly 600% increased
Duration of maceration time had strong influence on antioxidative activity
Trans-resveratrol Trans-piceid
Piceid concentrations 100% higher with French yeast Resveratrol concentrations up to 400%
Wines produced with Macedonian yeast had higher antioxidative activity than those with French yeast
Kostadinović et al. (2012) Duration of maceration (3, 6, 10 days), Merlot wine
French and Macedonian yeast, Merlot and Vranec wines
The table shows effects produced by variation of different parameters (e.g., temperature and duration of fermentation) during wine production on resveratrol concentration.
These findings suggest that thermovinification could be responsible for the enhancement of concentration of resveratrol in wine, but this effect, as shown in some studies, may also differ according to grape variety. Yeast selection Another important factor, which can significantly influence resveratrol content in wine, is yeast selection. However, only a few published reports address this topic. Vacca et al. (1997) showed that yeasts used for fermentation of must are among the factors responsible for the decrease of resveratrol content in wines. This was explained by the absorption of the compound on cell walls or absorption/metabolism by the yeast cells. The fact that different yeast types could influence resveratrol content was also confirmed by Kostadinović et al. (2012). The authors noticed an increase of resveratrol (up to four times) and piceid (up to two times) in Merlot wines produced using French yeast when compared with Macedonian yeast. It was observed (authors’ unpublished data) that when compared with spontaneous fermentation, addition of selected yeasts could result in an augmentation as well as a decrease of resveratrol content, depending on yeast variety and properties.
In addition, it has been established that yeasts’ β-glucosidase activity depends on maceration time (Vrhovsek et al., 1997), thus the final content of resveratrol and piceid is a result of yeast selection as well as maceration period. Addition of β-glucosidase from Aspergillus niger in Sicilian wines increased the transresveratrol content up to 75% (Todaro et al., 2008).
Effects of Winemaking Technologies on Total Phenolic Content It is well known that phenolic compounds present in wine can show a beneficial effect on human health. Therefore, clarification of the influence of different enological practices on phenolic level in wine is essential and this topic has been addressed for many years in scientific publications. The main results from selected publications focused on this topic are summarized in Table 60.2. Fermentation Temperature There are several published reports that confirm that higher fermentation temperatures increase phenolic extraction in wine. As far as the authors are aware, Ough and Amerine (1961) published the first observation
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TABLE 60.2 Effects of Winemaking Technologies on Total Phenolic Content in Wine—An Overview Reference
Experiment
Analyzed Parameter
Effect
Comment
Timberlake and Bridle (1976)
Fermentation on the skins Thermovinification (60°C, 30 min, then 45°C, 30 min) Carbonic maceration
Total phenolics (TP)
Carbonic maceration wine almost 20% higher TP than thermovinificated wine
Thermovinificated wine was much more colored
Girard et al. (2001)
Cold fermentation 15°C Ambient fermentation 20°C High temperature 30°C Modified cold fermentation 15°C
Total phenolics (TP)
High temperature of fermentation lead to almost 50% increase in total phenolics compared with modified cold fermentation
Higher fermentation temperature; increase permeability of the hypodermal cell; releasing anthocyanin; increased solubility of other phenolics in the wine solution
Different vinification yeasts Saccharomyces bayanus Saccharomyces cerevisiae
Total phenolics (TP)
For modified cold fermentation S. cerevisiae increased TP by 50%
Spranger et al. (2004)
Skin fermentation with stems (7, 21 days) 25°C Skin fermentation without stems (7 days) 25°C Carbonic maceration 35°C (21 days)
Total phenolic index (TP) Total anthocyanins (TA)
Duration had no significant influence Carbonic maceration wines significantly lower TA and TP than skin contact (average 20% lower for TP and 50 % lower for TA) Stem contact slightly increased TP
Although higher temperature may induce degradation-condensation of anthocyanins, it favors diffusion of other phenols during carbonic maceration
Atanacković et al. (2012)
Thermovinification 60°C for 30 min, 80°C for 3 min
Total phenolics (TP)
Increased total phenolic content in all thermovinificated samples (up to 100%)
Only for Pinot Noir, higher temperature (80°C) produced more phenolic compounds in wine Increased total phenolic lead to increased antioxidative activity of wine samples
The table shows effects produced by variation of different parameters (e.g., thermovinification, temperature, and yeast selection) during wine production on total phenolic content.
of fermentation temperature influence on phenolic content. It was noticed that the color of wines produced from Pinot Noir and Cabernet Sauvignon was more intense as the fermentation temperature increased. Some later reports for Pinot Noir confirmed that increasing temperature from 15 to 30°C significantly increases total phenolic content in wine (Girard et al., 2001). In another report by Spranger et al. (2004), it was observed that increased temperature (35°C) during carbonic maceration induces degradation or condensation of anthocyanins, but it can favor improved diffusion of other polyphenols from grape to wine and increase total phenolic content. Thermovinification After heating of intact or crushed grapes during thermovinification process, the grapes are pressed and must is inoculated with yeast strain for fermentation. Before fermentation, grape skins and seeds could be removed from must or left in during this process. Atanacković
et al. (2012) examined total phenolic content in wines made by two different thermovinification methods (Table 60.2) from four grape varieties (Merlot, Cabernet Sauvignon, Pinot Noir, and Prokupac). It was observed that increased temperature lead to higher phenolic content in all cultivars and accordingly increased antioxidative capacity of wine samples. Netzel et al. (2003) observed that heating of must (skins with liquid) results in higher concentration of anthocyanins, flavan-3-ols and flavonols in Pinot Noir, Lemberger, and Cabernet Franc varieties. Conversely, some other previously published results reported that thermovinification leads to improved color extraction (anthocyanins), but much lower total phenolic extraction (Auw et al., 1996). A similar trend was also observed for some Italian grape varieties (Stella et al., 1991). It is generally recognized that heat treatment can be effective in increased phenolic extraction if it is applied on must (containing grape skins and seeds) (Sacchi et al., 2005).
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Other Ways in Which Composition is Altered
Carbonic Maceration During carbonic maceration, whole berries and clusters are held under a carbon dioxide atmosphere and partial fermentation occurs because of the activity of glycolytic enzymes present in grapes (Flanzy, 1935). In order to complete fermentation, after 1–2 weeks, the grapes are pressed and the juice is inoculated. Timberlake and Bridle (1976) found that wines produced by carbonic maceration contained the highest amount of phenolic compounds and less anthocyanin and polymeric pigments when compared with wines made by thermovinification and fermentation on the skin. Similar results were obtained by Sun et al. (2001). Conversely, the study by Spranger et al. (2004) showed that carbonic maceration of Castelao wines resulted in the lowest phenolic as well as anthocyanin content. A study by Pellegrini et al. (2000) confirmed that the influence of carbonic maceration on total phenolics depends on grape variety. Maceration Time Extended maceration prolongs skin contact and the hypothesis that this process could increase extraction of phenolic compounds is supported by current literature. It has been shown that longer pomace contact increased the concentration of anthocyanins and tannins (10 versus 4 or 5 days). Also, aging in the bottle (1 year) of wine produced by longer pomace contact results in higher content of polymeric pigments (Gomez-Plaza et al., 2001). Prolonged maceration time for Merlot wines lead to an increase of total phenols up to 36 days, while pigments increased up to day 4, and then slowly decreased (Yokotsuka et al., 2000). On the contrary, another study did not reveal any significant difference between total phenols within 7 and 21 days’ skin fermented wine. Moreover, a decrease in anthocyanins was observed, probably because of their absorption on yeast or/and condensation and degradation (Spranger et al. 2004). Yeast There are a few published studies pertaining to the effect of yeast on phenolic content in wine. Obtained results showed that selected yeast could produce variable effects depending mainly on the grape variety studied. It has been observed that, applied to the same variety, differences could be obtained according to yeast strain (Cuinier, 1997; authors’ unpublished data). However, in some studies no major differences were observed in phenolic content as regards the use of different yeast. Zini et al. (2003) showed that application of three yeast strains on one variety gave similar phenolic content. Likewise, significant differences were not observed when comparing phenolic content in wines obtained from four grape varieties using five yeast strains (Nicolini et al., 2003).
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OTHER WAYS IN WHICH COMPOSITION IS ALTERED Other factors affecting phenolic content during the wine-making process were also investigated. Besides those previously mentioned, the factors that could have a positive effect on the increase of biologically active compounds in wine (when applied during wine making) are summarized below. Freezing the must before fermentation could influence the content of phenolics in wine. This process breaks cell membranes and thus can increase the extraction of anthocyanins and tannins. This was confirmed by Couasnon (1999), who observed a 50% increase in anthocyanins and tannins in three grape varieties (Merlot, Cabernet Sauvignon, and Cabernet Franc). Conversely, freezing the pomace separated from the juice resulted in a slight increase of anthocyanins, while the impact on total phenolic compounds varied. Low-temperature extraction in the absence of alcohol (cold soak) produced little difference in phenolic content. It has been shown that this process generally has negative or no effects (decrease of anthocyanins and flavonols) on phenolics. However, when combined with addition of sulfur dioxide, the increase of total phenolics and anthocyanins is pronounced (Gerbaux, 1993). Prefermentation juice run-off is a process aimed at increasing skin to juice ratio by removing juice before fermentation. The procedure is expected to increase concentration of phenolics from skins and seeds in wine. This was supported by the results obtained by Zamora et al. (1994) where increases in flavonoid and anthocyanin concentrations was observed when 10% juice was removed. An increase in phenolic content was also observed after applying the run-off technique by Gerbaux (1993). However, some studies showed different results. It has been noticed that 30% and 50% juice run-off (30% and 50% removal) results in variable effects on phenolic content in wines from different grape varieties (Atanacković et al., 2012). Inconsistent results after 10% and 20% juice removal were observed also by Gawel et al. (2001). It could be partially explained by solubility limitation, since there is less liquid for dissolution of targeted compounds. Addition of pectolytic enzymes can increase total phenols as well as wine color intensity. It has been demonstrated that pectinases improve extraction of phenolics (Daudt and Polenta 1999). In most cases, applied enzymes do not increase anthocyanis, but can increase the amount of other phenolic compounds (e.g., tannins). Additionally, it has been reported that higher sulfur dioxide levels can produce enlargement of pigment extraction during early fermentation, but final concentration of pigments as well as total phenolics in wines were not significantly higher (Bakker et al., 1998).
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Application of increased fermentation temperature, thermovinification, must freezing, and extended maceration during the wine-making process have been reported to increase phenolic content in wine. Conversely, other investigated factors, such as sulfur dioxide levels and cold-soak treatments have frequently been shown to have little or no lasting effects, or to lead to a decrease in phenolic levels.
ANALYTICAL TECHNIQUES Siemann and Creasy (1992) conducted the first analysis of resveratrol content in wine. The described HPLC analytical method included a complex extraction procedure and large sample volumes. Nowadays, numerous studies are focused on this topic. In the last 20 years, interest in resveratrol and quantification of this compound in different samples has rapidly increased, and a number of publications covering this topic have been published. The most commonly used method for adequate determination of all resveratrol forms is HPLC analysis. Some of the techniques applied are listed in Table 60.3. Successful identification and quantification of both resveratrol isomers (trans-, cis-) has been reported (Atanacković et al., 2012) as well as other resveratrol forms (piceid, resveratrol-glucuronide, etc.) (Soleas et al., 1997; Kostadinović et al., 2012). Reference standards for transresveratrol and trans-piceid are commercially available,
while corresponding cis-forms are usually obtained after in situ UV light exposure of trans-isomer solution (Cvejić et al., 2010; Netzel et al., 2003; Sun et al., 2003). The methods used could require sample preparation, as frequently used solid-phase extraction or classic liquid/ liquid extraction (Sun et al., 2003). Conversely, the increasingly used direct injection of wine samples has also been shown to provide satisfactory results (Netzel et al., 2003). There is a variety of detection methods for resveratrol determination using liquid chromatography. Most commonly used method is UV/DAD detection performed with or without sample preparation. Detection wavelengths are usually near the absorption maximum of investigated compounds (around 305 nm and 280 nm for trans- and cis-resveratrol, respectively). In addition, due to the physico-chemical properties of resveratrol, use of the fluorescent detector (FLD) is possible. This type of highly sensitive detection could allow measurement of small quantities of resveratrol (Atanacković et al., 2012). Also, a more specific mode of detection comparing to UV/DAD, FLD could be easily used for resveratrol quantification from a complex matrix such as wine, without any sample preparation. Mass spectrometry (MS) detection has been coupled with HPLC for reliable confirmation of resveratrol isomers and metabolites in different samples (Kostadinović et al., 2012). The most commonly used stationary phase for HPLC analysis of resveratrol is easily available octadecil reverse phase. Mobile phases applied for successful separation
TABLE 60.3 Analytical Procedures for Identification and Quantification of Resveratrol Reference
Analyte
Sample Preparation
Method
Conditions
Detection
Threlfall et al. (1999)
Trans-resveratrol
Quantification by standard addition method
HPLC Phenomenex bondclone phenyl column
Gradient elution Methanol/water pH 2.5
UV 310 nm
Netzel et al. (2003)
Trans-resveratrol Trans-piceid
Direct injection
HPLC RP C18 column
Gradient elution Acetonitrile/water/ formic acid
UV/DAD 310 nm
Sun et al. (2003)
TransCisresveratrol
SPE Liquid/liquid extraction
HPLC RP C18 column
Gradient elution Acetonitrile/water
UV 307 nm trans 285 nm cis
Todaro et al. (2008)
TransCisresveratrol
Liquid/liquid extraction
HPLC RP C18 column
Gradient elution Acetonitrile/ phosphoric acid
UV/DAD Wavelength not specified
Atanacković et al. (2012)
TransCisresveratrol
Direct injection
HPLC RP C18 column
Gradient elution Methanol/water/ formic acid
FLD Ex330 Em374 trans UV/DAD 280 nm cis
Kostadinović et al. (2012)
Trans-resveratrol Trans-piceid
Direct injection
HPLC RP C18 column
Gradient elution Acetonitrile/acetic acid/water
MS
The table shows the most commonly used analytical procedures for determination of resveratrol isomers in wine. HPLC, high-performance liquid chromatography; RP, reverse phase; C18, octadecyl bonded silica; UV/DAD, ultraviolet diode array detection; FLD, fluorescence detection.
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References
could vary, but consist mainly of a combination of frequently used solvents for HPLC analysis such as methanol, ethanol, acetonitrile, formic acid, and water. Another approach for resveratrol determination, which is not as frequently used as HPLC, is application of gas chromatography coupled with mass spectroscopy. Sample preparation includes solid-phase extraction or liquid extraction after which trimethylsylil resveratrol derivates are formed. The total phenolic amount is commonly determined with UV/Vis spectroscopy by applying Folin–Ciocalteu’s reaction. The results are expressed either as total phenolic index (Sun et al., 2001) or more frequently, as gallic acid equivalents in 1 l of wine (mg/l GAE) (Atanacković et al., 2012; Woraratphoka et al., 2007). Since antioxidative capacity is closely related to total phenolic content of wine, it is very often included in studies concerning phenolic content. It is usually estimated by DPPH (Atanacković et al., 2012) or TEAC tests (Netzel et al., 2003; Kostadinović et al., 2012). The individual phenolic compounds most abundant in wine (e.g., catehin, gallic acid, quercetin, etc.) are usually successfully identified and quantified with HPLC analysis using DAD. Nevertheless, analysis of different factors, which influence individual phenolic compounds in wine, is not extensively described in the literature. With respect to the importance of these natural compounds and their assumed health benefits, this subject is currently expanding.
References Atanacković, M., Petrović, A., Jović, S., Gojković-Bukarica, Lj., Bursać, M., Cvejić, J., 2012. Influence of winemaking technique on the resveratrol content, total phenolic content and antioxidant potential of red wines. Food Chem. 131 (2), 513–518. Auw, J.M., Blanco, V., O’Keefe, S.F., Sims, C.A., 1996. Effect of processing on the phenolics and color of Cabernet Sauvignon, Chambourcin, and Noble wines and juices. Am. J. Enol. Vitic. 47, 279–286. Bakker, J., Bridle, P., Bellworthy, S.J., Garcia-Viguera, C., Reader, H.P., Watkins, S.J., 1998. Effect of sulphur dioxide and must extraction on colour, phenolic composition and sensory quality of red table wine. J. Sci. Food Agric. 78, 297–307. Cimino, F., Sulfaro, V., Trombetta, D., Saija, A., Tomaino, A., 2007. Radical-scavenging capacity of several Italian red wines. Food Chem. 103, 75–81. Clarke, R.J., Bakker, J., 2004. Wine-Flavour Chemistry. Blackwell Publishing Ltd., Oxford. Couasnon, M.B., 1999. Une nouvelle technique: La maceration préfermentaire à froid-extraction à la neige carbonique. Premièr partie: Résultats oenologiques. Rev. Oenol. 92, 26–30. Cuinier, C., 1997. Ceppi di lievito e composizione fenolica dei vini rossi. Vignevini 7/8, 39–42. Cvejic, J.M., Djekic, S.V., Petrovic, A.V., Atanackovic, M.T., Jovic, S.M., Brceski, I.D., Gojkovic–Bukarica, Lj.C., 2010. Determination of trans- and cis-resveratrol in Serbian commercial wines. J. Chromatogr. Sci. 48, 229–234. Daudt, C.E., Polenta, G.A., 1999. Les phénols dans les moûts de Cabernet Sauvignon et d’Isabel soumis à divers traitements. J. Sci. Tech. Tonnellerie 5, 47–55.
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Flanzy, M., 1935. Nouvelle méthode de vinification. C.R. Acad. Agric. Fr. 21, 935–938. Frémont, L., 2000. Biological effects of resveratrol. Life Sci. 66 (8), 663–673. Gawel, R., Iland, P.G., Leske, P.A., Dunn, C.G., 2001. Compositional and sensory differences in Syrah wines following juice run-off prior to fermentation. J. Wine Res. 12, 5–18. Gerbaux, V., 1993. Etude de quelques conditions de cuvaison susceptibles d’augmenter la composition polyphénolique des vins de Pinot noir. Rev. Oenol. 69, 15–18. Girard, B., Yuksel, D., Cliff, M.A., Delaquis, P., Reynolds, A.G., 2001. Vinification effects on the sensory, colour, and GC profiles of Pinot noir wines from British Colombia. Food Res. Int. 34, 483–499. Gómez-Plaza, E., Gil-Muñoz, R., López-Roca, J.M., Martínez-Cutillas, A., Fernández-Fernández, J.I., 2001. Phenolic compounds and color stability of red wines: Effect of skin maceration time. Am. J. Enol. Vitic. 52, 266–270. Kostadinović, S., Wilkens, A., Stefova, M., Ivanova, V., Vojnovski, B., Mirhosseini, H., Winterhalter, P., 2012. Stilbene levels and antioxidant activity of Vranec and Merlot wines from Macedonia: Effect of variety and enological practices. Food Chem. 135, 3003–3009. Lopez-Velez, M., Martinez-Martinez, F., Del Valle-Ribes, C., 2003. The study of phenolic compounds as natural antioxidants in wine. Crit. Rev. Food Sci. Nutr. 43 (3), 233–244. Nicolini, G., Mattivi, F., Larcher, R., Volpini, A., 2003. Vinificazioni in rosato ed in rosso con lieviti selezionati: observazioni circa il colore. Enologo 39, 79–83. Ough, C.S., Amerine, M.A., 1961. Studies on controlled fermentation.V. Effects on color, composition, and quality of red wines. Am. J. Enol. Vitic. 12, 9–19. Paixao, N., Perestrelo, R., Marques, J.C., Camara, J.S., 2007. Relationship between antioxidant capacity and total phenolic content of red, rose´ and white wines. Food Chem. 105, 204–214. Pellegrini, N., Simonetti, P., Gardana, C., Brenna, O., Brighenti, F., Pietta, P., 2000. Polyphenol content and total antioxidant activity of vini novelli (young red wines). J. Agric. Food Chem. 48, 732–735. Sacchi, K.L., Bisson, L.F., Adams, D.O., 2005. A Review of the Effect of Winemaking Techniques on Phenolic Extraction in Red Wines. Am. J. Enol. Vitic. 56 (3), 197–206. Siemann, E.H., Creasy, L.L., 1992. Concentration of the Phytoalexin Resveratrol in Wine. Am. J. Enol. Vitic. 43 (1), 49–52. Soleas, G., Diamandis, E.P., Goldberg, D.M., 1997. Resveratrol: A molecule whose time has come? And gone? Clin. Biochem. 30, 91–113. Spranger, M.I., Climaco, M.C., Sun, B., Eiriz, N., Fortunato, C., Adelina, N., Leandro, M.C., Avelar, L., Belchior, A.P., 2004. Differentiation of red winemaking technologies by phenolic and volatile composition. Anal. Chim. Acta 513, 151–161. Stella, C., Testa, F., Viviani, C., Sabatelli, M.P., 1991. Trattamento a caldo delle uve: influenza su vini da vitigni diversi. Vignevini 12, 47–50. Stervbo, U., Vang, O., Bonnesen, C., 2007. A review of the content of the putative chemopreventive phytoalexin resveratrol in red wine. Food Chem. 101, 449–457. Sun, B., Ferrao, C., Spranger, M.I., 2003. Effect of wine style and winemaking technology on resveratrol levels in wines. Cienc. Tec. Vitivinic. 18 (2), 77–91. Sun, B., Spranger, I., Roque-do Vale, F., Leandro, C., Belchior, P., 2001. Effect of Different Winemaking Technologies on Phenolic Composition in Tinta Miúda Red Wines. J. Agric. Food Chem. 49, 5809–5816. Threlfall, R.T., Morris, J.R., Mauromoustakos, A., 1999. Effect of Variety, Ultraviolet Light Exposure, and Enological Methods on the transResveratrol Level of Wine. Am. J. Enol. Vitic. 50 (1), 57–64. Timberlake, C.F., Bridle, P., 1976. The effect of processing and other factors on the colour characteristics of some red wines. Vitis 15, 37–49. Todaro, A., Palmeri, R., Barbagallo, R.N., Pifferi, P.G., Spagna, G., 2008. Increase of trans-resveratrol in typical Sicilian wine using b-Glucosidase from various sources. Food Chem. 107, 1570–1575.
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60. FACTORS INFLUENCING WINE PHENOLICS, RESVERATROL
Vacca, V., Leccis, L., Fenu, P., Pretti, L., Farris, G.A., 1997. Wine yeasts and resveratrol content. Biotechnol. Lett. 19 (6), 497–498. Vrhovsek, U., Wendelin, S., Eder, R., 1997. Effects of various vinification techniques on the concentration of cis and trans resveratrol and resveratrol glucoside isomers in wine. Am. J. Enol. Vitic. 48, 214–219. Woraratphoka, J., Intarapichet, K.O., Indrapichate, K., 2007. Phenolic compounds and antioxidative properties of selected wines from the northeast of Thailand. Food Chem. 104, 1485–1490.
Yokotsuka, K., Sato, M., Ueno, N., Singleton, V.L., 2000. Colour and sensory characteristics of Merlot red wines caused by prolonged pomace contact. J. Wine Res. 11, 7–18. Zamora, F., Luengo, G., Margalef, P., Magriña, M., Arola, L., 1994. Nota. Efecto del sangrado sobre el color y la composición en compuestos fenólicos del vino tinto. Rev. Esp. Cienc. Tecnol. Aliment. 34, 663–671. Zini, S., Canuti, V., Siliani, A., Bertuccioli, M., 2003. Criomacerazione in Toscana: Esperienze sul Sangiovese. Ind. Bevande 32, 16–23.
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