Effect of the prefermentative addition of copigments on the polyphenolic composition of Tempranillo wines after malolactic fermentation

The influence of the prefermentative addition of copigments and different winemaking technologies on the polyphenolic composition of Tempranillo red wines after malolactic fermentation was studied. Six experiments dealing with the prefermentative addition of caffeic acid, rutin, (+) catechin, white grape skin tannin, white grape seed tannin and control wines were realised. Three different winemaking technologies (traditional vinification, prefermentative cold maceration at 6–8 °C and cold soak at 0–2 °C with dry ice) were studied. Prefermentative addition of copigments increases anthocyanin copigmentation reactions and produces wines with a greater colour, a higher anthocyanin concentration, a superior contribution of anthocyanins to the colour of the wine, a superior percentage of tannins polymerised with polysaccharides and less astringency. Cold prefermentative maceration increases the extraction of polyphenols, the anthocyanin copigmentation reactions and the polymerisation reactions between tannins and polysaccharides. The effectiveness of the combination of copigments and prefermentative maceration treatments was demonstrated by the increase of the concentration of the polyphenolic compounds.     

Application of high‐power ultrasounds during red wine vinification

Wine colour is one of the main organoleptic characteristics influencing its quality. It is of special interest in red vinifications due to the economic resources that wineries have to invest for the extraction of the phenolic compounds responsible for wine colour, compounds that are mainly located inside the skin cell vacuoles, where the volatile compounds are also found. The transfer of phenolic compounds from grapes to must during vinification is closely related to the type of grapes and the winemaking technique. During traditional winemaking, grapes are crushed and skin macerated for several days, with pumps overs to facilitate the colour extraction. To increase this extraction, some chemical (maceration enzymes) or physical technologies (thermovinification, cryomaceration, flash‐expansion) can be applied. In this work, a new methodology has been tested. This methodology consists in the application of high‐power ultrasounds to crushed grapes to increase the extraction of phenolic compounds. Crushed grapes were treated with this non‐thermal technology and vinified, with 3, 6 and 8 days of skin maceration time, and the results were compared with a control vinification, where crushed grapes were not subjected to any treatment and were skin macerated during 8 days. The wine chromatic characteristics (determined spectrophotometrically) and the individual phenolic compounds (anthocyanins and tannins, determined by HPLC) were followed during the maceration period, at the end of alcoholic fermentation and after two months in bottle. Also, the wine volatile compounds were determined by GC‐MS. The wines made with ultrasound‐treated grapes showed differences with the control wine, especially regarding total phenol content and tannin content. The wines elaborated with sonicated grapes and with only three days of skin maceration time presented similar concentration of anthocyanins and twice the concentration of tannins than control wines elaborated with 8 days of skin maceration.     

Comparison between the phenolic composition of Petit Verdot wines elaborated at different maceration/fermentation temperatures

The objective of this work was to contribute to the knowledge of the relationship between phenolic composition and the temperature of maceration/fermentation on Petit Verdot red wines, which were made with three treatments (17°C, 21°C, and 25°C). The phenolic compounds of Vitis vinifera cv. Petit Verdot wines elaborated at different maceration/fermentation temperatures were determined and compared by high-performance liquid chromatography coupled with diode array detector and electrospray ionization mass spectrometry. A total of 45 phenolic compounds were detected in all wines. The phenolic composition was affected by the temperature of maceration. The increment of maceration/fermentation temperature had a positive effect on the total concentration of the phenolic compounds and chromatic characteristics of these wines. The colour of Petit Verdot young red wines showed more colour intensity and their luminosity descended due to the increase in temperature. The highest total content of anthocyanins was determined in wines macerated at 21°C. However, other groups of phenolic compounds (flavonols, proanthocyanidins, and stilbenes) increased their total content by raising the maceration/fermentation temperature, reaching maximum values at 25°C.     

Anthocyanin profile of young red wines of Tannat,Syrah and Merlot made using maceration enzymes and cold soak

Anthocyanins are the main pigments of young red wines. The aim of this work was to evaluate the anthocyanin composition of red wines produced by alternative procedures of winemaking and different grape varieties. For this purpose, wines of Tannat, Syrah and Merlot were made by traditional maceration (TM), addition of maceration enzymes (ENZ) and cold soak (CS). Syrah wines had the highest proportions of malvidin (86.0 ± 1.0) and peonidin (5.5 ± 0.4), while Tannat wines had the highest of delphinidin (6.9 ± 0.8), petunidin (13.2 ± 0.6) and nonacylated glucosides (73.6 ± 0.6). Cold soak increased the anthocyanins contents in Tannat and Merlot wines. In turn, maceration enzymes affect the anthocyanin profile and the stability of the colour of wines. Discriminant analysis of data showed significant separation of the wines of each variety as the anthocyanin profile showed the varietal fingerprint, despite the different winemaking procedures.     

Sensory and chemical effects of two alternatives of prefermentative cold soak in Malbec wines during winemaking and bottle ageing

Two alternatives of cold soak (CS), traditional external refrigeration (CS‐T) and use of solid CO₂ (CS‐DI), were evaluated in Malbec wines and contrasted against a control (C) during winemaking and up to 24 months of bottle ageing. Sugar consumption up to 5 g L day^‐1 was observed in CS‐T during the CS period. Both the viability of the population of Saccharomyces and non‐Saccharomyces were maintained during CS. CS‐T was detrimental for the anthocyanin and phenolic content and caused a reduction of absorbance in the visible spectrum of the wines relative to C and CS‐DI. CS‐DI had an early positive effect in the anthocyanin content and chromatic properties, but this effect subsided after 6 months of bottle ageing relative to C. From a sensory standpoint, CS‐T had the lowest colour saturation and a marked acetaldehyde character. CS‐DI wines were the most saturated in colour at press and early ageing, whereas a balsamic‐like aroma developed during bottle ageing. C wines were characterised by red fruits aroma, reduction and astringency early during winemaking, but a decrease in astringency and the reduction character occurred during bottle ageing.     

Effect of the winemaking technique on phenolic composition and chromatic characteristics in young red wines

The effect of six winemaking techniques (traditional, prefermentative maceration, delestage, Ganimede fermentation system, enzymes and tannins addition, or oak chip addition during alcoholic fermentation) on phenolic composition and chromatic characteristics of young red wines, elaborated from Mencía grapes grown in Galicia (northwestern Spain), was studied. The evolution of phenolic compounds from grapes to bottling and its influence on CIELab parameters were investigated. After bottling, 26 phenolic compounds were determined by high-performance liquid chromatography (HPLC), and their influence on colour stability for ageing was evaluated. Principal component analysis allowed the differentiation of the winemaking techniques studied on the base of phenolic composition, which is correlated with polymerization grade of anthocyanins. This paper can contribute to improve the knowledge about the importance of selecting the winemaking technique to elaborate high-quality young red wines and to evaluate their ability for ageing. So, the addition of enzymes and tannins seems to be the most adequate winemaking technique to elaborate red wines for ageing as it results in the formation of major number of pigmented polymers that are stable over time. Nevertheless, the prefermentative maceration, Ganimede autowinemaker and the addition of oak chips can be used for the elaboration of young red wines.     

Improving colour extraction and stability in red wines: the use of maceration enzymes and enological tannins

Two commercially available maceration enzymes and two enological tannins were tested in Monastrell wines to determine their suitability for improving the chromatic characteristics, colour stability and sensory properties of the resulting wines. The greatest differences for all the wines, when comparing with the control wine, were observed at the beginning of the winemaking process, any differences diminishing in the finished wines. One of the enzyme‐treated wines was used showed hardly any difference from the control wine, whereas the other enzyme‐treated wine showed an improvement in their chromatic and sensory characteristics. The use of two different enological tannins did not provide any improvement in the chromatic and sensory characteristics of the wines, imparting a higher yellow colour and resulting in lower scores in the colour and aroma sensory characteristics, accompanied by a higher astringency, dryness and bitter sensory sensations.     

Phenolic profile of blackberry wine produced using Korean winemaking techniques in earthenware jars

This research evaluated the winemaking potential of ‘Natchez’ and ‘Triple Crown’ blackberries grown in Oklahoma and examined the phenolic composition of blackberry wines made using modified Korean traditional winemaking techniques. The winemaking variables were fermentation temperature (21.6 vs 26.6°C), and fermentation type (yeast inoculation vs wild fermentation). High‐performance liquid chromatography was used to examine the phenolic compounds in blackberry juice and wine. The phenolic compounds consisted of anthocyanins (kuromanin, keracyanidin, delphinidin) and phenolic acids (gallic acid, catechin, caffeic acid, epicatechin, p‐coumaric acid). The ‘Natchez’ berries had higher concentrations of anthocyanins (kuromanin) while ‘Triple Crown’ berries had higher levels of phenolic acids (p‐coumaric acid). For many compounds, a higher fermentation temperature generally corresponded to higher concentrations of the phenolic compound in the wine after three months aging, but this was not universally observed. Accordingly, fermentation temperature may best be matched with individual cultivars via experimentation in order to maximise extraction and retention of phenolic compounds in the finished wines. Overall, the Korean traditional winemaking technique may be a good technique to add value to wines made from blackberries suited for production in a mid‐continental climate such as the central USA. © 2018 The Institute of Brewing & Distilling     

Improvement of winemaking process using pulsed electric fields at pilot-plant scale. Evolution of chromatic parameters and phenolic content of Cabernet Sauvignon red wines

The influence of the application of a continuous pulsed electric fields treatment (PEF treatment) to grape pomace on the evolution of colour and phenolic content of Cabernet Sauvignon red wines has been investigated. Wine from grape treated by PEF presented at the end of alcoholic fermentation higher colour intensity (CI), total polyphenol index (TPI) and total anthocyanic content (TAC) than control wine. This effect was observed even although maceration time for PEF wine was 48 h shorter than for control. Differences remained during malolactic fermentation and maturation. After 4 months of aging in bottle, CI, TPI and TAC of PEF wine were 38%, 22% and 11% higher respectively than the control. HPLC phenolic profiles of wines were qualitatively similar, without detecting a selective effect on any phenol. No significant differences in sensory attributes between wines were detected. Results indicate that PEF is a promising technology in red winemaking for reducing the maceration time and increasing colour and phenolic extraction.     

Influence of winemaking technologies on phenolic composition of Italian red wines

The aim of this study was to assess the influence of different winemaking technologies on the chemical characteristics and, in particular, on the phenolic fraction of Aglianico, Montepulciano, Nero di Troia and Sangiovese wines produced in Apulia, Southern Italy. Four different winemaking technologies were compared: control (traditional, 5 days of maceration at 25 °C with three daily punching-down), prolonged maceration (10 days), addition of ellagic tannins and cryomaceration (24 h at 5 °C using dry ice), without any other oenological treatment. Results showed that the different technologies slightly influenced the phenolic fraction of Aglianico, which is known to be naturally rich of phenols. On the contrary, the prolonged maceration led to an increase of total phenols (TP) in Nero di Troia (2,592 mg/kg vs. 2,115 mg/kg of control) and a decrease in Sangiovese (869 mg/kg vs. 1,013 mg/kg); the addition of tannins led to an increase of TP in Montepulciano (1,358 mg/kg vs. 1,216 mg/kg) and to a decrease in Sangiovese (916 mg/kg vs. 1,013 mg/kg); and cryomaceration led to a decrease of anthocyanins in all cultivars (about 15%). Phenols extraction from grapes was found to be mostly dependent on the grape variety rather than on the applied winemaking technology.     

Influence of prefermentative maceration temperature on the colour and the phenolic and volatile composition of rosé wines

Prefermentative maceration for 8 h at 5, 10 and 15 °C was used to make rosé wines, and changes in their colour (colour intensity (CI), tone and CIELAB parameters), phenolic compounds (classic indices and individual compounds) and volatile compounds (major and minor) were monitored from the must stage to wines until 6 months after bottling. The 15 °C maceration temperature provided wines with the highest CI, a* and C* values, the greatest malvidin‐3‐glucoside content and the lowest alcohol and ethyl acetate levels. Only in these wines were terpenols released after 6 months in the bottle. The wines produced at 5 °C had the highest ester levels, which also remained more stable during storage. When using maceration temperature as the differentiating variable in a discriminant analysis, volatile compounds were important contributors. However, colour and phenolic compound parameters were important when sampling time was used as the differentiating variable. The best scoring wines in an informal sensory evaluation test were those subjected to 15 °C maceration, while the least appreciated were those macerated at 5 °C. Copyright © 2005 Society of Chemical Industry     

Influence of low temperature prefermentative techniques on chromatic and phenolic characteristics of Syrah and Cabernet Sauvignon wines

Low temperature prefermentative techniques (cold maceration, superficially frozen grapes and dry-ice frozen must) were studied as an enological alternative for obtaining highly colored wines and compared with other more common practices, such as the use of maceration enzymes during the maceration step. The experiments were conducted with two grape varieties (Syrah and Cabernet Sauvignon) during the 2007 season. Significant differences were found between the treatments at the three moments analyzed (at the end of alcoholic and malolactic fermentation, and at the moment of bottling). The cold maceration technique produced the highest concentration of anthocyanins in Cabernet Sauvignon wines. As regards chromatic parameters, the prefermentative low temperature techniques led to wines with a better color than the control wine although similar to the color obtained when a commercial maceration enzyme was used. Taking into account the results in both Cabernet Sauvignon and Syrah wines, freezing the must with dry-ice and the use of maceration enzyme were the most interesting techniques.     

Influence of grape composition and winemaking on the anthocyanin composition of red wines of Tannat

The anthocyanin composition of Tannat red wines obtained with four winemaking techniques was evaluated in different years. The wines were elaborated with traditional maceration (TM), cold pre‐fermentative maceration, delayed extraction of anthocyanins and extended maceration. Two vinifications were carried out for each technique, employing 70 kg of grapes in each one. The anthocyanin composition of wines was analysed by high‐performance liquid chromatography–diode array detection. The results confirm the fundamental role of the grape composition on the anthocyanin composition of the wines. The winemaking had an important effect on the total concentration of anthocyanins and also may modify the anthocyanic profile of wines. The wines obtained with TM had higher or similar content of anthocyanins than those elaborated with the other techniques. Canonical discriminant analysis of data showed that vintage has a greater effect on anthocyanin concentration than winemaking techniques.     

Effect of the time of cold maceration on the evolution of phenolic compounds and colour of Syrah wines elaborated in warm climate

The effect of different cold maceration times on Syrah red wines from warm climate has been evaluated. Differential colorimetry and tristimulus colorimetry were applied to colour data at different points of the vinification stage. Virtually, all the phenolic compounds showed significantly higher content in cold macerated wines, even more when longer contact time was used. Long cold macerated (LCM) wines had the significantly (P < 0.05) highest chroma values (C*_ab) and lowest of lightness (L*) and hue (h_ab). Unexpectedly, wines submitted to short‐time cold maceration (SCM) presented the lowest chroma values, even significantly inferior to that observed in traditional macerated (TM) wines. Moreover, colour changes (ΔE*_ab) between TM and SCM were mainly quantitative (%Δ²L and %Δ²C), whereas they were also qualitative when compared TM with LCM (%Δ²C and %Δ²H). Cold maceration in warm climates characterised by common colour losses must be carefully employed because undesirable consequences on colour may occur.     

Effect of the dry ice maceration and oak cask fermentation on colour parameters and sensorial evaluation of Tempranillo wines

The impact of dry ice maceration (DIM) and oak cask fermentation (OCF) on characteristics of Tempranillo wines elaborated in a warm climate has been studied as an alternative procedure to traditional red winemaking (CT) to obtain highly coloured wines. Oenological and colour parameters were measured to determine the influence of these techniques on wines along the winemaking process. DIM and OCF techniques were found significantly different to CT for colour intensity and percentage of blue. Moreover, both induced easily perceptible changes in CIELAB coordinates (lower L*, higher a* and values) than CT and also affect main wine's sensory attributes (e.g. increased polyphenols extraction in DIM and to a lesser extent OCF, and therefore produced wines with higher colour than CT). Although differences tend to decrease with ageing, these practices seem feasible alternatives to improve quality characteristics of young red wines from grapes grown in warm climates.     

The glycerol and ethanol production kinetics in low-temperature wine fermentation using Saccharomyces cerevisiae yeast strains

Increasing glycerol production in low-temperature wine fermentation is of concern for winemakers to improve the quality of wines. The objective of this study was to investigate the effect of 10 different Saccharomyces cerevisiae on the kinetics of production of glycerol, ethanol and the activities of glycerol-3-phosphate dehydrogenase (GPD) and alcohol dehydrogenase (ADH) in low-temperature fermentation. Ethanol production was influenced by temperature, and it was slightly higher at 13 °C than at 25 °C. Glycerol yields were significantly affected by both temperature and strains. More glycerol was produced at 25 °C than at 13 °C because the activity of GPD was higher at 25 °C than at 13 °C. Glycerol production of the different yeast strains was up to 3.19 and 3.18 g L⁻¹ at 25 and 13 °C, respectively. Therefore, isolating the yeast strains with high glycerol production and adaptation to low-temperature fermentation is still the best method in winemaking.     

Impact of maceration time on colour‐related phenolics,sensory characteristics and volatile composition of mulberry wine

This study investigated the effect of maceration treatment on colour‐related phenolics, sensory characteristics and volatile composition in mulberry wine. Pre‐fermentation maceration was performed for 2 days (‘short’), 6 days (‘medium’) and 8 days (‘long’), respectively, followed by the same fermentation process. Results showed that the long maceration (LM) caused higher level of anthocyanins in wine, especially cyaniding‐3‐O‐rutinoside, cyaniding‐3‐O‐glucoside and dephinidin‐3‐O‐glucoside, whereas the short maceration caused lower level of phenolic acids in wine. The medium maceration (MM) wine showed the highest level of flavonols but the lowest concentration of flavan‐3‐ol. The LM wine exhibited greater red tone and colour intensity accompanied by higher amounts of free and copigmented anthocyanins. The LM wine showed lower levels of alcohols, acids, terpenoids, benzenes and sulphur compounds, whereas the lowest level of esters was found in the MM wine. The LM wine had reduced fruity and floral aroma and overall flavour complexity compared with the other wines. Copyright © 2018 The Institute of Brewing & Distilling     

Changes in chromatic characteristics and phenolic composition during winemaking and shelf-life of two types of red sweet sparkling wines

The Brachetto variety is the most important aromatic red grape used for the production of sweet sparkling wines in Italy. The phenolic composition and chromatic characteristics were studied in base and red sweet sparkling wines made from this variety. The present work represents the first study on sparkling wines manufactured with Brachetto grapes. The amount of pigments extracted in the base wine was low as a consequence of the necessity for short maceration time (48 h) and low alcohol content (< 3.5% v/v). The second fermentation (prise de mousse) caused a pigment content decrease, accompanied by both a color intensity decrease and a tonality increase. In terms of phenolic compounds and chromatic characteristics, lightly sparkling wines (final bottle pressure < 1.7 bar) agreed with fully sparkling wines (final bottle pressure > 3.0 bar) at the end of the second fermentation and, therefore, the chromatic quality was independent on the winemaking methodology used, excepting for lightness and color intensity.Response surface methodology was applied to predict the effect of two independent variables, namely time and temperature of storing, on the phenolic composition and chromatic properties in both lightly and fully sparkling wines. So, it is possible to evaluate the development of two types of sweet sparkling wines during their ageing in bottle and their commercial shelf-life. A central composite design (CCD) and response surface methodology (RSM) were used for this purpose. Quantitative changes were observed in the color parameters. Although the time variable strongly influenced them, the two sparkling wines were stable enough only at low temperatures after 12 months of ageing. During the wine ageing in bottle, an increase in the formation of polymeric red pigments can be suggested taking into account the losses observed in monomeric anthocyanins. The results obtained showed that the color of fully sparkling wines was more stable than that of lightly ones and, therefore, the shelf-life of the former ones could be longer.     

Influence of the yeast strain on Monastrell wine colour

Two commercial yeast strains were assayed during the winemaking process of Monastrell grapes to determine their influence on colour and phenolic composition of the resulting wines during alcoholic fermentation and maturation. The results showed that in 2002, the wines did not present great differences but in 2003 higher colour intensity and phenolic compounds content were detected when one of the commercial strains was used. A discriminant statistical analysis clearly showed that different yeasts led to different wines as regard their chromatic characteristics.Industrial relevanceThe importance of yeast in winemaking is extensively known since they are responsible for the transformation of sugars into ethanol and for the formation of the most significant aroma compounds in wines. However, they may also participate in wine colour and this role is usually not taken into account in the wine industry. The choice of a yeast strain is an important factor since these microorganisms have the capacity to retain or adsorb phenolic compounds and, on the other hand, yeast may contribute to stabilizing wine colour, as a result of participating in the formation of vitisins during fermentation or liberating mannoproteins that have the capacity to bind to anthocyanins and tannins, protecting them from precipitation. Two commercial yeast strains were assayed during the winemaking process of Monastrell grapes to determine their influence on colour and phenolic composition of the resulting wines during alcoholic fermentation and maturation. The results showed that higher colour intensity and phenolic compounds content were detected when one of the commercial strains was used, both during fermentation and wine aging, and may be used as a tool during winemaking for obtaining stable and highly coloured wines.