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Article

Influence of Pre-Fermentation Treatments on Wine Volatile and Sensory Profile of the New Disease Tolerant Cultivar Solaris

1
Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 30, Frederiksberg C DK-1958, Denmark
2
Department of Plant and Environmental Science, Faculty of Science, University of Copenhagen, Højbakkegård Alle 13, Tåstrup DK-2630, Denmark
*
Author to whom correspondence should be addressed.
Molecules 2015, 20(12), 21609-21625; https://doi.org/10.3390/molecules201219791
Submission received: 6 October 2015 / Revised: 22 November 2015 / Accepted: 27 November 2015 / Published: 3 December 2015
(This article belongs to the Collection Wine Chemistry)

Abstract

:
Solaris is a new disease tolerant cultivar increasingly cultivated in cool climate regions. In order to explore the winemaking processes’ potential to make different styles of Solaris wines, the effects of different pre-fermentation treatments (direct press after crushing, whole cluster press, cold maceration, and skin fermentation) on the volatile profile, chemical, and sensory properties of Solaris wines were investigated. Cold maceration treatment for 24 h and fermentation on skin led to wines with lower acidity and higher glycerol and total polyphenol indexes. Sensory analysis showed that cold maceration enhanced “apricot” and “apple” flavor while skin fermentation gave rise to increased “rose” and “elderflower” flavor. The PLS regression model revealed that fruity flavor of cold macerated wines was related to a combination of esters while β-damascenone and linalool were correlated to the “rose” and “elderflower” flavor. This study provides information about pre-fermentation techniques that allowed the possibility of obtaining wines with different styles.

Graphical Abstract

1. Introduction

The style of a typical wine strongly depends on various factors such as cultivar, year of harvest, winemaking practices, and climate conditions, of which the winemaking process is one of the most important factors. Pre-fermentation treatments (e.g., acid and sugar adjustment) are critical in cool and cold climate regions due to the fact that the grapes may not have ripened optimally. In addition, the presence and concentration of wine aroma components are significantly influenced by the applied pre-treatment techniques, as a high amount of aroma precursors are located in the grape skin and pulp. To enhance and optimize extraction of flavor components and precursors, cold maceration (CM) which refers to the release of components from the pomace (seeds, skins, and pulp) after crushing is often applied in white wine making. This process strongly determines the final styles of wine produced [1,2,3,4,5]. Extended extraction can also be achieved by skin fermentation (SF) in order to make fully-flavored and complex styles of white wine [6]. Some important volatiles, such as C-6 alcohols and aldehydes are derived originally from the solid parts of grape berry and, therefore, promoted by increased extraction through maceration [7,8,9]. Additionally, maceration enhances the concentration of many non-volatiles such as polyphenols which in turn result in more mouthfeel and in higher levels of antioxidants in the final wine [10,11,12]. Sensory assessments have demonstrated that these pre-treatments confer fresh properties to white wines [5], enhance flavor intensity [9,13], and improve fruity and floral flavor [14,15] in the wines, while may also add bitterness to white wines.
However, maceration practices are largely cultivar dependent, and vary with vineyard and vintage conditions [16]. The influence of maceration on the amount of most volatiles depends on temperature and duration [17,18]. Low maceration temperature is normally employed in white wine making, while duration may vary from wine to wine. For instance, Selli et al. [2] investigated “Muscat” wines produced with 6 h of maceration at 15 °C and found higher quality than after 12 h. In another study, the concentration of terpenes, norisoprenoids, and benzene compounds in “Albillo” wines was considerably enhanced by CM for 15 and 23 h [5]. Furthermore, the total aroma concentration increased with the extension of CM time in “Chardonnay” wines [19]. However, no differences were detected for most free volatiles between macerated and non-macerated “Listán blanco” wines [20]. In this sense, the development of suitable winemaking techniques for specific cultivars is crucial in a certain location/region.
“Solaris” is a new disease tolerant cultivar grown in northern Europe with advantages such as stable yields and reliable berry ripening despite the cool climate [21]. An average of 97 days is required to fully ripen the berries and the typical yield is 0.5 kg/m2 (from year 2007 to 2014). “Solaris” has an average must of 20.9 °Brix and about 9.4 g/L titratable acidity and is considered to be ripe every year over the last 10 years in Denmark. It is largely predominant in Denmark, England, Southern Sweden and other regions in Northern Europe (The Netherlands, Belgium, North Germany, and Poland), producing a good single varietal wine. Selecting the best cultivars is crucial, especially in marginal and cool climate regions, to explore the potential of making different styles of wine, specific winemaking techniques for the cultivar need to be developed. However, to date, little is known about the potential of different wine style production from this newly-released cultivar, especially on the impact of different pre-fermentation processes on Solaris wine quality. Therefore, the overall aim of this study was to investigate the influence of different pre-fermentation treatments on volatile profile, chemical parameters, and sensory features of “Solaris” white wines.

2. Results and Discussion

In order to reduce the effect of factors other than the maceration treatments, grapes from the same vineyard were used. The overall ripeness of “Solaris” grapes in 2011 were at a good level with 21.1 °Brix in the direct pressed must. This density means that the wine has the potential to obtain an alcohol level considered optimal for a white wine style from a cool region as Denmark, being not too alcohol dominant while grapes were still ripe enough to have a good flavor potential. Details of pre-fermentation treatments are shown in Table 1.
Table 1. Pre-fermentation treatments applied in the study in “Solaris” white wines.
Table 1. Pre-fermentation treatments applied in the study in “Solaris” white wines.
Wine CodePre-Fermentation Treatments
DPDirect press after crushing
WCWhole cluster press
6H_CM6 h cold maceration
24H_CM24 h cold maceration
6H_CM + SF6 h cold maceration + 30 h skin fermentation
24H_CM + SF24 h cold maceration + 30 h skin fermentation

2.1. Impact of Pre-fermentation Treatments on Wine Chemical Parameters

The pre-fermentative treatments WC and DP resulted in low levels of potassium, yeast assimilable nitrogen (YAN) in the juice and low pH in the wine (Table 2), in accordance with general oenology literature [16]. CM treatment increased YAN from moderate in DP sample to high level in 6H_CM and 24H_CM samples. Additionally, CM increased pH but addition of SF during early fermentation did not result in any further pH increase (Table 2). However, when measured in the young wine titratable acidity and especially tartaric acid levels were significantly influenced by the time of skin contact. The lower tartaric acid levels and higher pH observed after 24H_CM + SF could be due to the higher potassium (Table 2) or other cations extracted from the grape skins during skin fermentation [22], which made further deacidification unnecessary in this wine. As deacidification has been shown to have no or very limited effect on the volatile profile of wine (unpublished results from our lab), the acidity effects of the treatments were balanced by deacidification up to 2.50 g/L on the rest of experimental wines.
Table 3 shows that the later cold stabilization further reduced and stabilized acidity in the final wines. The levels of ethanol values ranged from 12.2% to 12.9% with a tendency of increasing levels after CM and SF. Additionally, the total polyphenol index was higher in the final wines with longer skin contact (24H_CM + SF wine). The present result was in line with previous studies [10,11,23]. Volatile acidity was generally low indicating a reductive and successful winemaking process. In addition, the concentration of glycerol was around 6 g/L in all wines matching the level of alcohol produced by the yeast. The concentration is above the taste threshold level for glycerol (5.2 g/L in wine) and may, thus, positively contribute to the smoothness of the final wines [24].
Table 2. Chemical parameters of “Solaris” juice and young wines after completing of fermentation and levels of deacidification with calcium carbonate.
Table 2. Chemical parameters of “Solaris” juice and young wines after completing of fermentation and levels of deacidification with calcium carbonate.
ParametersPre-fermentation Treatments
DPWC6H_CM24H_CM6H_CM + SF24H_CM + SF
Juice
°Brix21.121.221.321.8--
Potassium (in juice, g/L)0.71 a,b0.52 b0.87 a,b0.94 a--
Ammonia (mg/L)107109108113--
α-Amino nitrogen (mg/L)188 b184 b238 a233 a--
YAN276 b274 b326 a327 a--
Wine
pH3.18 c3.09 d3.31 b3.40 a3.36 a3.43 a
Tartaric acid (g/L)5.33 b5.52 a4.69 c4.14 d3.69 e2.97 f
Titratable acidity (g/L)9.57 b10.2 a8.91 c8.36 d8.40 d7.93 e
Deacidification (g/L)2.502.001.001.001.00-
Different letters in the same rows indicates significant differences according to Tukey’s HSD test (p < 0.05); YAN was estimated by using formular [YAN] = 0.8225 × [ammonia] + [α-amino nitrogen].
Table 3. Chemical parameters of the final “Solaris” white wines.
Table 3. Chemical parameters of the final “Solaris” white wines.
ParametersWines
DPWC6H_CM24H_CM6H_CM + SF24H_CM + SF
Ethanol (% v/v)12.2 c12.5 b12.4 b12.7 a12.8 a12.9 a
pH3.43 a,b3.23 b3.41 b3.48 a3.51 a3.37 b
Titratable acidity (g/L)6.40 c7.58 a6.80 b6.44 c6.20 c6.77 b
Volatile acid (g/L)0.180 a,b0.190 a,b0.270 a0.270 a0170 a,b0.150 b
Tartaric acid (g/L)1.81 a,b2.10 a2.31 a1.34 a,b1.00 b1.00 b
Malic acid (g/L)3.21 d3.35 c,d3.56 b,c3.60 b,c3.70 a,b3.95 a
Fructose (g/L)0.640 b0.600 b0.630 b1.33 a0.600 b0.540 b
Total polyphenol index12.6 c12.2 b,c18.5 b16.3 b,c18.5 a,b21.9 a
Glycerol (g/L)5.95 b6.23 b6.09 a,b6.11 a,b,c5.74 a,b,c6.60 a
Reducing sugar (g/L)0.690 d0.960 c0.840 c1.47 a0.92 c,d1.19 b
Different letters in the same rows indicates significant differences according to Tukey’s HSD test (p < 0.05).

2.2. Impact of Pre-Fermentation Treatments on Volatile Profile in Wine

In total, 71 volatile compounds, comprising 35 esters, 16 alcohols, seven aldehydes, eight terpenes, two ketones, two sulfur compounds, and one C13-norisoprenoid, were quantified in the wines. Table 4 shows concentrations of volatile compounds and their sensory descriptions. Thresholds and odor activity values (OAV) are also listed in the table. OAV allows estimation of the contribution of each volatile compound to wine aroma. It was determined by dividing the concentration by the odor threshold value of the compound reported in wine or matrix similar to wine, otherwise in water if not available in wine. To take the uncertainty of the calculated OAVs and the synergetic or additive impact of several volatile compounds into account, it was assumed that aroma compounds having an OAV of 0.1 or higher might be important in wine aroma.
Esters are both synthesized by the grapes and arise from the alcoholic fermentation. Esters are important in wine flavor due to their pleasant fruity odor. In this work, esters represent the most abundant group of volatiles detected and quantified in the wines, and nine might contribute to wine aroma directly due to their relatively high OAVs (Table 4, compounds in bold). CM and SF treatments had various impacts on the individual esters. Among nineteen identified ethyl esters, eight had OAV > 0.1 in all samples and among these, four were significantly influenced by the applied treatments. For example, the concentration of ethyl decanoate was significantly higher in 24H_CM wine than the rest of wines. Ethyl decanoate has been previously reported to provide fruity aroma to white wines [13]. CM and SF pre-treatments did not enhance the formation of ethyl esters of branched acids, for instance, ethyl 2-methylpropanoate, ethyl 2-methylbutanoate, and ethyl 3-methylbutanoate. This could be due to the high concentrations of amino nitrogen in CM wines. Ethyl 3-methylbutanoate exhibited the highest OAV (2.6) in WC wine. Ethyl 3-methylbutanoate has also been reported as an important odorant in Croatian “Rhine Riesling” wine [25].
The acetate esters, generated by the reaction of acetyl-CoA with higher alcohols from degradation of amino acids or fatty acids, were generally not significantly affected by CM and SF treatments. Only three acetates had OAV > 0.1 and all of them were not affected by the treatments. However, a slightly higher concentration of acetates was observed in 24H_CM wine. Dennis et al. [26] found that the content of an acetate ester increased with the pre-fermentation concentration of the corresponding precursor in a model must. Our results suggest a similar relationship between benzyl acetate and its precursor benzyl alcohol, as both increased in parallel in CM and SF wines (Table 4).
With respect to other esters (fatty acid esters of higher alcohols), the amount of methyl hexanoate, methyl octanoate, methyl decanoate, and methyl salicylate increased by CM and SF treatments. However, these esters are most probably not important to the wine aroma as all of them were present at levels far below their individual odor thresholds.
The influence of the maceration process on the concentration of esters depends on many factors, for instance, temperature [27], and grape cultivar [28] and it is difficult to draw any general conclusions. The amount of methyl octanoate was increased by CM treatment in this study, whereas the opposite effect was revealed in “Cabernet Sauvignon” wines [15].
Alcohols are the second major group of volatile components in “Solaris” wines. Higher alcohols generally have characteristic pungent odor and give complexity to wine flavor, which in turn influences the character of wines. They are the main fermentation derived products by the yeast via sugar catabolism or decarboxylation and deamination of amino acids [29]. As can be seen in Table 4, 3-methyl-1-butanol and 2-phenylethanol (OAV 2.4) were by far the most predominant by amount among the 11 identified higher alcohols. Despite their very high concentrations, the sensory impact was minor due to high sensory thresholds. It should be noted that the quantification of 3-methyl-1-butanol is imprecise due to overloaded peaks. A high initial nitrogen concentration generally results in decreased production of higher alcohols related to amino acid production [30]. In the present work, the amount of 2-methylpropanol, 1-propanol, and 2-phenylethanol decreased with increasing skin contact could be correlated the increased amount of YAN in the must with longer maceration (Table 2). However, a significant increase of the amount of 2-phenylethanol was observed in 24H_CM + SF wines. One possible reason could be that extensive skin contact increased the availability of some amino acids contributing to the biosynthesis of 2-phenylethanol which occurs preferentially in berry skin as suggested by Slegers et al. [31]. Nevertheless, its concentration was above threshold in all wines which might not relate to the sensory variations among studies wines.
The concentration of benzyl alcohol increased significantly with the CM and SF treatments, this is likely to be due to an increased extraction of glycosylated precursors [32,33].
C-6 compounds are originally present in crushed grape must, resulting from the enzymatic oxidation of grape polyunsaturated fatty acids through the lipoxygenase pathway [29]. In this sense, unsurprisingly, WC wine contained the lowest content of C-6 alcohols (Table 4). The 24 h CM generally favored the yield of C-6 alcohols in our study and this was in agreement with studies in “Albillo” and “Narince” wines [2,5], as well as “Chardonnay”, “Muscat” and “Cabernet Sauvignon” wines [8,18,28]. In this study, however, these C-6 alcohols exhibited concentrations lower than their odor threshold, and therefore may not be sensed in the aroma of the macerated wines.
Eight aldehydes and two ketones were detected in all wines, but most of them were not significantly affected by the treatments and the OAVs of these compounds were relatively low, except for 3-methylbutanal (OAV around three). Only hexanal and benzaldehyde showed significant changes as they increased in 24H_CM + SF wine, indicating skin fermentation enhanced the formation of these compounds. Hexanal can be produced from oxidation of 1-hexanol as discussed by Campo et al. [34] or by enzymatic oxidation of C18 unsaturated fatty acids [29]. Benzaldehyde, which has a bitter almond character, is considered a sensory important benzene compound in wine [29]. In this study it was, however, found in a concentration much lower than the threshold (OAV < 0.01). According to Paloma et al. [5], shorter maceration had no significant effect on benzaldehyde in “Albillo” wine which is in agreement with our present study in 6H_CM wine. However, Vazquez et al. [3] observed that maceration and enzyme treatment largely increased benzaldehyde. The higher level of benzaldehyde in the 6H_CM + SF and 24H_CM + SF wines probably related to the levels of benzyl alcohol in the wines (Table 4). However, it can also originate from oxidation reactions by yeast on amino acids (phenylalanine), glycoside precursors, phenol compounds of the grape, or from some secondary compounds like phenyl acetic acid and p-hydroxybenzoic acid [35,36].
Terpenes are varietal compounds derived from the grapes where they often are found to be glycosidically-bound. They are usually associated with floral notes in wine aroma [29]. In this study, eight terpenes, including terpene alcohols and some of their oxides, were identified in the wines. Among them, linalool was dominating with the highest concentration and OAV in all wine samples. WC and DP wines had relatively low amount of linalool and hotrienol and their concentrations were below their thresholds. However, applied maceration caused an increase of these terpenes and this effect was more pronounced in skin fermented wines (6H_CM + SF and 24H_CM + SF). A good example would be the level of linalool which was significantly increased by SF treatment and reached the highest odor activity levels in the 24H_CM + SF wine. Moreover, (E)-β-ocimene and α-terpineol were significantly increased by SF but they had concentrations far below their thresholds. The presence of terpenes in wine is typically due to direct extraction of these compounds and the breakdown of glycoconjugates in the skin and in the solid parts of berry cells during the process of CM [2,9,18,22,36]. In addition, some of these predominant monoterpenes, such as linalool, hotrienol, and α-terpineol can also be formed from geraniol during vinification [37].
With regard to other compounds, two sulfur compounds (S-methyl thioacetate and 2-methyldihydro-3(2H)-thiophenone) and one C13-norisoprenoid (β-damascenone) were detected in all samples. Like some of the terpenes, the amount of β-damascenone was significantly increased by CM and SF treatments. This effect was in agreement with other studies [5,20]. The concentration of this compound exceeded its odor threshold in all samples. β-Damascenone can be formed by oxidative degradation of carotenoids during grape crushing, while a more probable source for damascenone in wine is acid-catalyzed rearrangement of C13 intermediates, with oxidation occurring in the grape during ripening [38].These precursors are, presumably, extracted to a greater extent during winemaking. β-Damascenone is an important trace compound with very low perception threshold (0.05 µg/L) in wine and gives wines fruity and honey odor [29].
Table 4. Volatile compounds quantified in the wines under different pre-treatments. Values are presented as averaged concentrations over two replicates (μg/L). For compounds exhibiting significant differences between treatments, values labelled with different letters.
Table 4. Volatile compounds quantified in the wines under different pre-treatments. Values are presented as averaged concentrations over two replicates (μg/L). For compounds exhibiting significant differences between treatments, values labelled with different letters.
CodeCompoundsCal. LRI 1Std. LRI 2Odour Description 3Concentration (μg/L)Sig.OdorOAV 5
DPWC6H_CM24H_CM6H_CM + SF24H_CM + SFThreshold (μg/L) 4
Esters
Ethyl esters
e1Ethyl propanoate971962Fruit202221199183213209ns1800 (1)0.11–0.12
e2Ethyl 2-methylpropanoate969969Sweet, rubber28.6 a,b36.9 a22.9 b,c24.3 b,c14.9 c16.7 c**15 (2)0.99–2.5
e3Ethyl butanoate10381040Apple346327351414391364ns20 (2)17–1
e4Ethyl 2-methylbutanoate10531058Apple1.79 a,b2.28 a1.34 b1.32 b0.97 b1.20 b**1 (2)0.97–2.28
e5Ethyl 3-methylbutanoate10721079Fruit6.17 a,b7.90 a4.43 b,c4.15 c3.69 c4.51 b,c*3 (2)1.2–2.6
e6Ethyl pentanoate11531150Yeast, fruit0.4200.3420.4370.5010.3870.455ns94 (3)<0.001
e7Ethyl (E)-butenoate11781174-4.9104.3405.2805.9406.5805.680ns--
e8Ethyl hexanoate12631255Apple peel, fruit9949469701070950870ns5 (2)170–210
e9Ethyl (E)-3-hexenoate13271327Pineapple, fruity0.189 a,b0.161 a,b0.236 a0.175 a,b0.116 b0.980 b*--
e10Ethyl heptanoate13541351Fruit0.100 c0.100 c0.142 b,c0.166 b0.179 b0.233 a***220 (1)<0.001
e11Ethyl lactate 13531353Fruit59.055.151.335.454.762.8ns157,360 (1)<0.001
e12Ethyl octanoate14471450Fruit, fat617544648743661560ns14 (4)39–53
e13Diethyl succinate16911689Wine, fruit16001280139085013001820ns200,000 (1)0.0043–0.010
e14Ethyl 2-furoate1641--7.257.506.226.438.098.85ns16,000 (5)<0.001
e15Ethyl decanoate16491651Grape180 a,b120 b174ab231 a160 a,b110 b**200 (5)0.55–1.2
e16Ethyl benzoate16861690Heavy, floral, fruity7.239.5816.08.768.1210.7ns575 (5)0.020–0.030
e17Ethyl 9-decenoate17031705Fruit--0.0680---***100 (6)<0.001
e18Ethyl dodecanoate18541861Leaf3.50 a1.21 c3.50a3.83 a2.95 b1.37 c*500 (7)<0.01
e19Ethyl myristate20712064Floral, honey0.2020.1880.2000.1280.05210.0700ns2000 (6)<0.001
Total Ethyl esters 405035603850359037804050ns
Acetate esters
ac1Propyl acetate981978Sweet, fruity,144113178212185146ns4700 (1)0.024–0.045
ac22-Methylpropyl acetate10171018Fruit, apple, banana87.670.610312993.981.1ns1600 (8)0.041–0.081
ac3Butyl acetate10781082Pear5.253.395.479.046.193.77ns1880 (1)<0.001
ac43-Methylbutyl acetate11401142Banana10,300864010,90011,90010,2009110ns30 (2)290–360
ac5Hexyl acetate12991293Fruit, herb198139199233149112ns1500 (1)0.075–0.15
ac6(Z)-3-Hexenyl acetate13271328Green, banana0.0160-----***--
ac7(E)-3-Hexenyl acetate13331337Sweet, Green, Sharp-fruity4.97 a,b2.34 b4.45 a,b9.84 a5.41 a,b3.50 a,b*--
ac8Benzyl acetate17491738Fresh, boiled vegetable--0.214 b0.494 a0.430 a,b0.457 a**2 (9)<0.001
ac9Phenethyl acetate18371835Rose, honey, tobacco361255332358351334ns250 (2)1.0–1.4
Total acetate esters 11,100922011,80012,80011,0009790ns
Other esters
oe1Methyl hexanoate11981196Fruit, fresh, sweet0.648 b0.648 b1.03 b1.73 a1.97 a2.04 a***84 (10)0.0077–0.024
oe2Isopentyl butanoate12891289Sweet, apricot, banana0.2780.3750.3180.2740.3040.353ns--
oe3Methyl octanoate14001401Orange0.263 b0.224 b0.484 a,b0.841 a,b0.984 a0.872 a,b*--
oe4Methyl decanoate16061608Wine0.0569 a,b0.0447 b0.0910 a,b0.171 a0.167 a0.136 a,b*1200 (4)<0.001
oe53-Methylbutyl octanoate16681672-2.781.852.072.512.601.99ns125 (5)0.015–0.022
oe6Methyl salicylate18001797Pepper, mint0.305 a,b0.130 b0.516 a,b0.641 a0.550 a0.500 a,b*--
oe7Ethyl phenylacetate1806-Fruit, sweet1.901.881.291.441.582.06ns--
Total other esters 6.23 b,c5.15 c5.79 b,c7.61 a,b8.16 a7.95 a,b*
Alcohols
Higher alcohols
alc11-Propanol10411041Alcohol, pungent447 a,b357 a,b502 a296 a,b188 b217 b*9000 (11)0.024–0.056
alc22-Methyl-1-propanol11041100Wine, solvent, bitter1020106012101040906970ns40,000 (2)0.023–0.030
alc31-Butanol11641165Medicine, fruit251216267348227196ns150,000 (4)<0.001
alc43-Methyl-1-butanol12371238Whiskey, malt, burnt>10,000>10,000>10,000>10,000>10,000>10,000ns30,000 (2)>0.33
alc51-Pentanol12791274Balsamic59.4 b58.8 b61.6 a,b64.8 a,b71.0 a,b98.5 a*64,000 (1)<0.001
alc61-Heptanol14681471Chemical, green10.210.08.619.3614.517.7ns--
alc72-Ethyl-hexanol15021499Rose, green0.9810.9911.251.361.691.42ns8000 (6)<0.001
alc81-Octanol15701573Chemical, metal, burnt7.386.899.046.3511.214.1ns900 (6)0.01–0.016
alc9Decanol17741778Fat0.4900.4500.6190.6160.6990.862ns400 (8)<0.001
alc102-Phenylethanol19361935Honey, spice, rose, lilac18,500 a,b11,400 b,c17,200 b,c9590 c20,100 a,b24,400 a*10,000 (2)1.1–2.4
alc11Benzyl alcohol18961897Sweet, flower36.6 b37.2 b103 a105 a154 a151 a***200,000 (4)<0.001
C6 alcohols
alc121-Hexanol13731372Resin, flower, green3250 a,b1730 b2900 a,b2340 a,b3520 a,b4280 a*8000 (2)0.22–0.54
alc13(E)-3-Hexenol13821386Grass16.6 a,b,c10.0 c12.3 b,c17.7 a,b20.2 a23.1 a**150,000 (1)<0.001
alc14(Z)-3-Hexenol13981390Grass1.86 c1.06 d2.44 c4.65 a3.15 b3.29 b***400 (2)<0.001
alc15(E)-2-Hexenol14211420Green, leaf, walnut0.502 c0.377 c1.12 b,c1.79 a,b1.92 a,b2.53 a**15,000 (12)<0.001
alc16(Z)-2-Hexenol14301430Leaf, green, wine, fruit0.321 c0.218 c1.10 b1.98 a1.85 a2.06 a***--
Aldehydes
ald13-Methylbutanal921917Malt13.614.613.713.913.916.7ns4.6 (1)3.0–3.6
ald2Hexanal10871087Grass, tallow, fat1.40 b1.18 b1.25 b1.31 b1.76 a,b2.08 a*9.1 (13)0.13–0.24
ald3Heptanal11941192Fat, citrus, rancid0.4720.4390.4060.5430.4770.554ns--
ald4Octanal13131311Fat, soap, lemon, green0.8870.4610.7270.8970.8240.566ns--
ald5Nonanal14051402Fat, citrus, green1.13 a,b0.789 b0.982 b1.45 a,b1.79 a1.31 a,b*15 (14)0.053–0.12
ald6Decanal15101511Soap, orange peel, tallow0.2870.2120.3260.3800.4000.410ns10 (4)0.021–0.041
ald7Benzaldehyde15411537Almond, burnt sugar3.84 b3.03 b4.82 b7.52 b12.5 b15.7 a**2000 (11)<0.01
Total aldehydes 21.3 a,b20.8 b22.2 a,b26.0 a,b31.7 a,b37.4 a**
Ketones
k12-Heptanone11921190Soap0.6430.5670.7260.7180.9770.853ns--
k2Acetoin13101307Butter, cream2.98 b2.27 b3.23 b5.66 a1.89 b1.96 b***150,000 (1)<0.001
Total ketones 3.632.843.966.382.872.81ns
Terpenes
t1Myrcene11711170Balsamic, must, spice0.0667 a,b-0.0764 a,b0.0904 a,b0.139 a0.174 a*36 (13)0.0040–0.012
t2Limonene12001200Lemon, orange0.2560.2800.2780.3540.6340.596ns15 (4)0.017–0.042
t3(E)-β-Ocimene12771277Herbaceous, mild, citrus, sweet, orange0.205 b0.212 b0.259 b0.333 a,b0.507 a0.567 a**--
t4p-Cymene12911283Lemon, fruity0.08450.1040.04270.04360.07060.0841ns11.4 (13)<0.001
t5Neroloxide14821485Oil, flower5.695.896.806.836.758.93ns--
t6Linalool15591560Flower, lavender7.85 b,c4.61 c11.8 b12.2 b12.40 b21.7 a*15 (8)0.31–1.4
t7Hotrienol16231621Hyacinth2.52 c2.06 c7.37 b6.57 b7.55 b14.6 a*100 (13)0.021–0.15
t8α-Terpineol17121716Oil, anise, mint2.26 b,c1.30 c2.48 b,c3.40 b3.49 b5.76 a***250 (8)<0.001
Total terpenes 18.9 c14.5 c29.1 b,c29.9 b,c31.5 b52.4 a***
Other compounds
ot1S-Methyl thioacetate10501050Rotten, cooked vegetables1.04 b0.980 b0.954 b0.443 c0.973 b1.41 a*4500 (15)<0.001
ot2Dihydro-2-methyl-3(2H)-thiophenone15461544Cabbage, onion, must3.333.081.981.385.485.00ns--
ot3β-Damascenone18411844Apple, rose, honey0.310 c0.217 c0.583 b,c1.07 a,b1.56 a1.61 a***0.05 (2)4.3–32
Total other compounds 4.68 b4.28 b3.52 b2.90 c8.02 a8.02 a**
Significance levels: ns: not significant, *: p ≤ 0.05, **: p ≤ 0.01, ***: p < 0.001. Different letters in the same rows indicates significant differences according to Tukey’s HSD test; 1 The retention indices (RIs) of volatiles were calculated as the retention time of the volatiles normalized to the retention times of adjacently eluting n-alkanes (C6–C22) [39]; 2 Linear retention indices (LRI) calculated from authentic standard compounds analyzed on the same system; 3 Odour descriptions based on flavournet and pherobase online databases; 4 Odour threshold. (1) Etiévant, 1991 [40]; (2) Guth, 1997 [41]: (3) Takeoka, et al. 1995 [42]; (4) Gómez-Míguez, et al. 2007 [43]; (5) Ferreira, et al. 2000 [7]; (6) Tao, et al. 2010 [44]; (7) Moyano, et al. 2002 [45]; (8) Ferreira, et al. 2002 [46]; (9), Buttery, et al. 1982 [47]; (10) Takeoka, et al. 1991 [48]; (11) Peinado, et al. 2004 [13]; (12) Franco, et al. 2004 [49]; (13) Ahmed, et al. 1978 [50]; (14) Cullere, et al. 2004 [51]; (15) Moreira, et al. 2010 [52]. Odor threshold values were reported in wine-like matrices, except for (3), (9), (10), and (13) which were measured in water; 5 OAV: Odor activity value was calculated by dividing the concentration by the odor threshold value of the compound. Compounds with OAV > 0.1 are in bold. Only the loweset and highest values were showed in the table.

2.3. Sensory Evaluations

According to the ANOVA, significant differences among samples were observed for the following 10 descriptors: O_Green Vegetable, O_Apricot and O_Muscat, F_Rose, F_Elderflower, F_Green Berry, F_Apple, F_Apricot F_Muscat, and F_ Green Vegetable. A spider plot was conducted using only the significant descriptors (Figure 1). In general, the wine vinified from WC showed the lowest scores of most attributes, indicating a weak aroma compared to the other wines. Two CM wines (6H_CM and 24H_CM) had higher values of descriptors but in different direction: 6H_CM wine was more linked with “F_Green Vegetable” while 24H_CM had a higher score of “F_Aprcot”. The DP wine was highly characterized by “F_Green Vegetable”, “O_Green Vegetable”, and “F_Green Berry”, whereas the most intense skin contact 24H_CM + SF wine had the highest values in the floral descriptors “F_Rose” and “F_Elderflower”. However, it should be noted that the 24H_CM + SF wine also had the highest value of “F_Green Vegetable”, indicating that combining maceration and skin fermentation increased floral notes but meanwhile exacted more green flavor from the grape skin. Furthermore, the effect of SF on perception of muscat characteristic was more pronounced since two samples with SF treatments (6H_CM + SF and 24H_CM + SF) were highly correlated with “F_Muscat” descriptor.
Figure 1. Sensory profile of six wines produced from different pre-fermentation procedures; Significant differences are shown: *: p ≤ 0.05, ***: p < 0.001; Suffix to the sensory descriptors indicates the type of assessment by panellists: O_: odor, F_: flavor.
Figure 1. Sensory profile of six wines produced from different pre-fermentation procedures; Significant differences are shown: *: p ≤ 0.05, ***: p < 0.001; Suffix to the sensory descriptors indicates the type of assessment by panellists: O_: odor, F_: flavor.
Molecules 20 19791 g001
The influence of pre-treatment techniques on the sensory properties of wines has been previously reported. Palomo et al. [5] stated that “Albillo” wines produced with skin contact were higher in green apple, apricot, and peach notes than those of un-macerated wines. Similarly, Losada et al. [9] observed that white “Godello” wines made from must with 36 h macerated wines had the highest score for general quality. Longer maceration could have negative effect on wine quality, such as the increased extraction of phenolic compounds which result in more bitter taste [16]. In this work, samples were not significantly different in terms of bitter taste. This indicates that the relative low maceration temperature and short extraction time applied may only extract flavonoids in a lesser extent, herein limiting the bitterness in wine.

2.4. Relationship between Instrumental Analysis and Sensory Properties of Wines

A Partial Least Squares (PLS) regression model was established to investigate the correlation between volatile compounds and chemical parameters (X-matrix) and significant sensory attributes (Y-matrix). The first two PLS components explained 72% of the total variance in the X-matrix and 62% for the Y-matrix. The score plot (Figure 2a) visualizes the differences and similarities of wines produced from various treatments. CM + SF wines (in the right part of the plot) were distinguished from the others in the left part of the plot mainly by PC1. 24H_CM wine was distinguished by PC2 while small variation between WC and DP wines was observed. In the loading plot shown in Figure 2b, most volatile compounds were located in the right side, positively linked with PC1, indicating that CM combined SF treatments resulted in high amount of most volatile compounds. Additionally, the CM + SF wines had higher scores in most sensory attributes studied. On the contrary, DP and WC wines were characterized by low levels of most aroma compounds while higher in “O_Green Vegetable” odor.
Figure 2. Partial Least Squares Regression (PLS) of wines correlation score (a) and loading plots (b) of the first two PCs. X-matrix: volatile compounds (blue, compounds with OAV > 0.1 are in black bold), chemical parameters; Y-matrix: sensory descriptors (red). The inner and outer ellipses represent R2 = 50% and 100%, respectively.
Figure 2. Partial Least Squares Regression (PLS) of wines correlation score (a) and loading plots (b) of the first two PCs. X-matrix: volatile compounds (blue, compounds with OAV > 0.1 are in black bold), chemical parameters; Y-matrix: sensory descriptors (red). The inner and outer ellipses represent R2 = 50% and 100%, respectively.
Molecules 20 19791 g002
It is noticeable that the flavor attribute “F_Apricot” (mainly high in 24H_CM wine), was closely correlated with several fermentation-derived acetates, such as 3-methylbutyl acetate (OAV: 360, r = 0.82, p < 0.05), 2-methylpropyl acetate (r = 0.89, p < 0.05) and butyl acetate (r = 0.82, p < 0.05). Additionally, some ethyl esters of straight-chain fatty acids such as ethyl decanoate (OAV: 1.2) and ethyl octanoate (OAV: 53), normally described as having grape and fruity characteristics, were positively correlated to the “F_Apricot” (r = 0.75, p < 0.1, and r = 0.72, p < 0.1, respectively). Moreover, the “F_Apple” attribute was associated to ethyl hexanoate (OAV: 210, r = 0.85, p < 0.05) and hexyl acetate (OAV: 0.15, r = 0.81, p < 0.05) with fruity and apple peel characteristics. Among these esters that showed high correlation to fruity flavor, only ethyl decanoate was significantly different between samples. Some other acetates with low OAVs were also grouped close to the fruity flavor in 24H_CM wine (Figure 2b). This indicated that the perceived high fruity flavor in 24H_CM wine might be due to a combination of many esters. The contribution of esters to the fruity note of wine aroma was previously demonstrated by many studies [53,54,55,56]. Among their observations, Vilanova et al. [53] stated that the fruity flavor of Spanish “Albariño” wine was mainly related to esters, for instance, ethyl octanoate and ethyl hexanoate.
The “F_Rose” descriptor which characterized wines with SF treatment was correlated to volatile compounds typically derived from grapes, i.e., nerol oxide (r = 0.96, p < 0.01), linalool (r = 0.92, p < 0.01) with OAV 1.4 and β-damascenone (r = 0.84, p < 0.05) with OAV 32 in 24H_CM + SF sample. These compounds were highly related to “F_Elderflower” as well. Both linalool and β-damascenone had high OAVs and showed large difference between samples, which thus could explain the high scores of “F_Rose” descriptor in the wines with SF treatment. Correlation between terpenes and floral descriptors has been reported in the literature [53] where the high amounts of monoterpenes mostly contributed to the floral characteristics of “Albariño” wine. Furthermore, Campo et al. [54] confirmed that linalool was an important contributor to the floral, sweet, and muscat descriptors in Spanish white wines. In one more recent study, Vilanova et al. [56] reported that the highest score of floral aroma perceived in “Blanco lexítimo” wine was attributed to the presence of linalool in this type of wine.
Few compounds were correlated with green vegetable (odor and flavor) in this study as most compounds had lower level in DP and WC wines, only (Z)-3-hexenyl acetate and 1-hexanol (r = 0.81, p < 0.05 and r = 0.87, p < 0.05, respectively) showed positive correlations. However, these two compounds did not present high odor activity in DP and WC wines, and the variation of 1-hexanol among different treatments was relative small (OAV between 0.22 and 0.54). Several studies illustrated that the green vegetable flavor was often related to 3-alkyl-2-methoxypyrazines, such as 3-isobutyl-2-methoxypyrazine (IBMP), 3-sec-butyl-2-methoxypyrazine (SBMP) and 3-isopropyl-2-methoxypyrazine (IPMP) even at very low concentrations (ng/L) [57,58,59]. In this study, compounds that were responsible for the green flavor might therefore not be detected. More sensitive techniques, like selected ion monitoring could be applied in future studies. Another potential explanation for more intense green flavor in the DP wine could be that lower concentrations of fruity compounds and, thus, less masking of green flavor, as described by Hein et al. [60].

3. Experimental Section

3.1. Chemical Standards

Chemical standards of volatile compounds were supplied by Sigma-Aldrich (St. Louis, MO, USA), Fluka (Madrid, Spain), Merck KGaA (Darmstadt, Germany). Ethanol (HPLC grade, 99.9%) and l(+)-tartaric acid (>99.5%) were from Sigma-Aldrich (Kiev region, Ukraine).

3.2. Grapes and Winemaking

Grapes of “Solaris” (Merzling × Gm 6493 (Zarya severa × Muscat Ottonel), cross made in 1975 Freiburg, Germany and varietal protection in 2001)) were cultivated in the field at the fruit genebank and research station “Pometet” (Copenhagen, Denmark) on 30th September in 2011 after 772 GDD (10 °C base T). The plants were trained in a VSP (vertical shoot position) system and the basic structure of the plant was a short stem with two short cordons (V shape) and pruned with a short two-budded stab and a long cane on each head. Planting distance is 1.5 m in the row and 3 m between rows.
Microvinification was performed in the cellar at “Pometet” in glass fermentation vessels of 5 L–10 L size. “Solaris” grapes were divided into six batches of 40 kg from which wines were made in duplicate. Different treatments were carried out for each batch as listed in Table 1. In the first batch, the grapes were pressed immediately after destemming and crushing, which was referred to DP wine. The second batch of grapes were pressed using the whole clusters without destemming (WC wine). The rest of the grapes were destemmed, crushed together and then divided into four portions and subjected either to cold maceration at 10 °C for different hours (6H_CM and 24H_CM wines), or to cold maceration combined with skin fermentation for 30 h in 10 L buckets covered with lid (6H_CM + SF and 24H_CM + SF wines). CO2-cover was used to protect the grape mash from oxidation during handling. Pressing of all treatments was done with a 20 L hydropress (Speidel, Ofterdingen, Germany). The cloudy juice of all samples was stored overnight in a cold room (3 °C) to allow settling and racked into new vessels to obtain clear juice for fermentation. The treatments with initiated SF continued fermentation directly after pressing. All batches were inoculated with the commercial yeast Saccharomyces cerevisiae, bayanus (Lalvin DV10TM from Lallemand) at 0.2 g/L, and moved to an 18 °C temperature-controlled room. All wines were fermented to dryness. After fermentation, wines were racked and 50 mg/L SO2 was added. Based on a preliminary bench test, wines revealed relatively high acidity. In order to minimize the dominance of sourness during sensory evaluation, between 0 and 2.5 g/L of acidity was removed using calcium carbonate (Table 2). The levels of deacidification applied were based on a pre-test in 100 mL scale on the newly fermented young wines. The pre-test included a sensory evaluation to determine the deacidification needed in each wine. Finally, the wines were moved to 3 °C for cold stabilization for four weeks after which the wines were racked again. Free SO2 was adjusted to 30–35 mg/L and the wines were bottled in 375 mL bottles and stored at 14 °C. The analyses were made after two months.

3.3. Chemical Parameters Analysis

°Brix, potassium, ammonia, α-amino nitrogen, ethanol, pH, volatile acidity, tartaric acid, malic acid, fructose, total phenolic index (Folin-Ciocalteu index), glycerol, and reducing sugar were determined using a WineScan instrument (WineScan™ FT120: Foss, Hillerød, Denmark) based on Fourier Transformed Infrared Spectrophotometry. The calibration of the instrument was validated by parallel measurements of chemical parameters of 75 Danish wines, of which 10 commercial Solaris wines. A good agreement was found with R2 ranged from 0.9 to 0.96 between traditional methods and WineScan method for the different parameters. Therefore it was decided to use WineScan to measure the chemical parameters of the experimental wines. Titratable acidity was determined by titrating with 0.33 M NaOH solution to a pH end-point of 8.2 and expressed in g/L of tartaric acid equivalents. All samples were analyzed in duplicate.

3.4. Volatile Compound Analysis

Dynamic headspace sampling (DHS) was applied to extract aroma compounds. Twenty mL of each wine was transferred to a 100 mL flask and 1 mL of 4-methyl-1-pentanol (50 mg/L, Aldrich, Steinheim, Germany) was added as an internal standard. The sample was equilibrated to 37 ± 1 °C and then purged with a nitrogen flow of 100 mL/min for 20 min with magnetic stirring at 200 rpm. The volatile compounds were trapped on a Tenax-TA tube (200 mg, mesh size 60/80, Buchem BV, Apeldoorn, The Netherlands). After purging, the tube was dried directly with nitrogen for 10 min to remove excess water. System control samples were run by using an empty flask at the same condition as the wine samples. All samples were analyzed in duplicate.
The collected volatile compounds were analyzed according to methodology developed in our lab [61] by a thermal desorption (ATD 30, PerkinElmer, Norwalk, CT, USA) gas chromatography mass spectrometry system (GC-MS, 7890A GC system interfaced with a 5975C VL MSD with Triple-Axis detector from Agilent Technologies, Palo Alto, CA, USA) equipped with a DB-Wax column (J & W Scientific 30 m × 0.25 mm × 0.25 mm). GC-MS data was analyzed using MSD Chemstation G1701EA (Version E.01.00.237, Agilent Technologies Inc., Palo Alto, CA, USA). The column pressure was held constant at 2.4 psi resulting in an initial flow rate of approximately 1.2 mL/min using hydrogen as carrier gas. The column temperature was kept at 30 °C for 10 min, increased at 8 °C/min to 240 °C, and finally kept isothermal for 5 min. The mass detector conditions were: electron-impact ionization (EI) at 70 eV, a scan range of 15–300. The MS transfer line was set to 225 °C. The identification of volatile compounds was achieved by matching their mass spectra with those of a standard library (Wiley275.l, HP product no.G1035A) and with those of pure authentic standards. To further verify the identification, linear retention indices (LRI) were calculated with a homologous series of alkanes (C5–C22) (Hewlett-Packard Co, Avondale, PA, USA) and compared to those of the authentic standards and/or literature values (Table 4).
Quantification of the volatile compounds was carried out from calibration curves obtained by each compound in synthetic wine. The synthetic wine was a 12% (v/v) ethanol solution in water containing 3.5 g/L of l-(+)-tartaric acid and the pH was adjusted to 3.4 with 5 M NaOH. Individual standard compounds were accurately weighed and dissolved in ethanol (99.9%) and then combined and diluted with synthetic wine to obtain a relevant range of concentrations. One mL of internal standard was added to the stock solution of each calibration level that was further extracted and analyzed under the same conditions as the wine sample. Standards were analyzed in triplicate.

3.5. Sensory Evaluation

A descriptive sensory analysis was conducted by a panel of eleven trained winemakers (four females and seven males, graduating from “Bayerischen Landesanstalt für Weinbau und Gartenbau” in Veitshöchheim, Germany). A set of sensory descriptors, including nine odors (O_Rose, O_Elderflower, O_Green Vegetable, O_Green Berry, O_Apple, O_Apricot, O_Pineable, O_Citrus, O_Muscat), eleven flavours (F_Rose, F_Elderflower, F_Green Vegetable, F_Green Berry, F_Apple, F_Apricot, F_Pineapple, F_Citrus, F_Muscat, F_Sulfurous, F_Body), three tastes (T_Bitter, T_Sourness, T_Sweetness) and astringency was generated by the panel. Panelists were then asked to score the wines on an unstructured, 15-cm linear scale using the attribute list. 30 mL of each wine was served in standard wine-tasting glasses coded with three digit numbers. The samples were presented in randomized order to minimize systematic carry-over effects. Cold water was used as palate cleansing. All the evaluations were done in ventilated tasting rooms at 20 °C in duplicate.

3.6. Statistical Analyses

One-way analysis of variance (ANOVA) was applied to concentrations of volatile compounds measured from fermentation duplicates by JMP 9.0.2 (SAS Institute, Cary, NC, USA) using sample as fixed effect and post-hoc by Tukey’s HSD test. Two-way ANOVA was performed on sensory data (products and assessors as the fixed factors) using PanelCheck V1.4.0 (Matforsk, Tromsø, Norway). Correlations between chemical composition (X-matrix) and sensory attributes (Y-matrix) were investigated by partial least squares regression (PLS) analysis using Unscrambler version 9.7 (CAMO ASA, Oslo, Norway).

4. Conclusions

The current study was the first to investigate the influence of different pre-fermentation treatments on the properties of “Solaris” wines. Cold maceration (CM) combined skin fermentation (SF) reduced acidity, leading to wines with slightly higher ethanol, glycerol, and total polyphenol index. SF combined with 24 h of CM treatment tended to make “F_Rose” and “F_Elderflower” notes more pronounced in the final wines. These treatments also enhanced formation/extraction of some volatile compounds such as C-6 alcohols, linalool and β-damascenone, while various effects were found on esters depending on the compounds. The pure CM treatment reduced the intensity of “F_Green Vegetable” and “F_Green Berry” sensory characteristics and enhanced the “F_Apricot” and “F_Apple” notes. Finally, whole cluster press (WC) and direct press (DP) generally resulted in wines with low content of aroma compounds and, thus, a weak flavor. The PLS regression revealed that fruity flavor was closely related to the combination of esters, while “F_Rose” and “F_Elderflower” were correlated to β-damascenone and linalool. In conclusion, when making “Solaris” wines, proper pre-treatments, such as cold maceration and short fermentation on skin are capable to modify the volatile profile of wines, which in turn can diversify the wine style and influence the quality.

Acknowledgments

This work was financially supported by The Danish Ministry of Food, Agriculture and Fisheries, Faculty of Science, University of Copenhagen and Chinese Scholarship Council (CSC).

Author Contributions

T.B.T.A. and M.A.P. designed and supervised the research; T.B.T.A., M.A.P. and S.J.Z. performed the research and analysed chromatographic data; J.L. contributed in analysing sensory data; S.J.Z. performed the statistical analysis and wrote the paper. All authors read, edited, made corrections, and approved the final manuscript.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Selli, S.; Cabaroglu, T.; Canbas, A.; Erten, H.; Nurgel, C. Effect of skin contact on the aroma composition of the musts of Vitis vinifera L. cv. Muscat of Bornova and Narince grown in Turkey. Food Chem. 2003, 81, 341–347. [Google Scholar] [CrossRef]
  2. Selli, S.; Canbas, A.; Cabaroglu, T.; Erten, H.; Günata, Z. Effect of skin contact on the free and bound aroma compounds of the white wine of Vitis vinifera L. cv Narince. Food Control 2006, 17, 75–82. [Google Scholar] [CrossRef]
  3. Vazquez, L.C.; Perez-Coello, M.S.; Cabezudo, M.D. Effects of enzyme treatment and skin extraction on varietal volatiles in Spanish wines made from Chardonnay, Muscat, Airen, and Macabeo grapes. Anal. Chim. Acta 2002, 458, 39–44. [Google Scholar] [CrossRef]
  4. Cabaroglu, T.; Canbas, A.; Baumes, R.; Bayonove, C.; Lepoutre, J.P.; Gunata, Z. Aroma composition of a white wine of Vitis vinifera L. cv. Emir as affected by skin contact. J. Food Sci. 1997, 62, 680–683. [Google Scholar] [CrossRef]
  5. Palomo, E.S.; González-Viñas, M.A.; Díaz-Maroto, M.C.; Soriano-Pérez, A.; Pérez-Coello, M.S. Aroma potential of Albillo wines and effect of skin-contact treatment. Food Chem. 2007, 103, 631–640. [Google Scholar] [CrossRef]
  6. Singleton, V.L.; Sieberhagen, H.A.; Wet, P.D.; Vanwyk, C.J. Composition and Sensory Qualities of Wines Prepared from White Grapes by Fermentation with and without Grape Solids. Am. J. Enol. Vitic. 1975, 26, 62–69. [Google Scholar]
  7. Ferreira, V.; Lopez, R.; Cacho, J.F. Quantitative determination of the odorants of young red wines from different grape varieties. J. Sci. Food Agric. 2000, 80, 1659–1667. [Google Scholar] [CrossRef]
  8. Ferreira, B.; Hory, C.; Bard, M.H.; Taisant, C.; Olsson, A.; Lefur, Y. Effects of Skin Contact and Settling on the Level of the C18/2, C18/3 Fatty-Acids and C6 Compounds in Burgundy Chardonnay Musts and Wines. Food Qual. Preference 1995, 6, 35–41. [Google Scholar] [CrossRef]
  9. Losada, M.M.; Andrés, J.; Cacho, J.; Revilla, E.; López, J.F. Influence of some prefermentative treatments on aroma composition and sensory evaluation of white Godello wines. Food Chem. 2011, 125, 884–891. [Google Scholar] [CrossRef]
  10. Darias-Martin, J.J.; Rodriguez, O.; Diaz, E.; Lamuela-Raventos, R.M. Effect of skin contact on the antioxidant phenolics in white wine. Food Chem. 2000, 71, 483–487. [Google Scholar] [CrossRef]
  11. Gomez-Miguez, M.J.; Gonzalez-Miret, M.L.; Hernanz, D.; Fernandez, M.; Vicario, I.M.; Heredia, F.J. Effects of prefermentative skin contact conditions on colour and phenolic content of white wines. J. Food Eng. 2007, 78, 238–245. [Google Scholar] [CrossRef]
  12. Olejar, K.J.; Fedrizzi, B.; Kilmartin, P.A. Antioxidant activity and phenolic profiles of Sauvignon Blanc wines made by various maceration techniques. Aust. J. Grape Wine Res. 2015, 21, 57–68. [Google Scholar] [CrossRef]
  13. Peinado, R.A.; Moreno, J.; Bueno, J.E.; Moreno, J.A.; Mauricio, J.C. Comparative study of aromatic compounds in two young white wines subjected to pre-fermentative cryomaceration. Food Chem. 2004, 84, 585–590. [Google Scholar] [CrossRef]
  14. Garcia-Romero, E.; Perez-Coello, M.; Cabezudo, M.D.; Sanchez-Munoz, G.; Martin-Alvarez, P.J. Fruity flavor increase of Spanish Airen white wines made by brief fermentation skin contact. Food Sci. Technol. Int. 1999, 5, 149–157. [Google Scholar] [CrossRef]
  15. Cai, J.; Zhu, B.Q.; Wang, Y.H.; Lu, L.; Lan, Y.B.; Reeves, M.J.; Duan, C.Q. Influence of pre-fermentation cold maceration treatment on aroma compounds of Cabernet Sauvignon wines fermented in different industrial scale fermenters. Food Chem. 2014, 154, 217–229. [Google Scholar] [CrossRef] [PubMed]
  16. Jackson, R.S. Fermentation. In Wine Science, 3rd ed.; Jackson, R.S., Ed.; Academic Press: San Diego, CA, USA, 2008; pp. 332–417. [Google Scholar]
  17. Esti, M.; Tamborra, P. Influence of winemaking techniques on aroma precursors. Anal. Chim. Acta 2006, 563, 173–179. [Google Scholar] [CrossRef]
  18. Selli, S.; Canbas, A.; Cabaroglu, T.; Erten, H.; Günata, Z. Aroma components of cv. Muscat of Bornova wines and influence of skin contact treatment. Food Chem. 2006, 94, 319–326. [Google Scholar] [CrossRef]
  19. Arnold, R.A.; Noble, A.C. Effect of Pomace Contact on the Flavor of Chardonnay Wine. Am. J. Enol. Vitic. 1979, 30, 179–181. [Google Scholar]
  20. Rodrıguez-Bencomo, J.J.; Méndez-Siverio, J.J.; Pérez-Trujillo, J.P.; Cacho, J. Effect of skin contact on bound aroma and free volatiles of Listán blanco wine. Food Chem. 2008, 110, 214–225. [Google Scholar] [CrossRef] [PubMed]
  21. Ambrosi, H.; Hill, B.; Maul, E.; Rühl, E.; Schmid, J.; Schumann, F. Farbatlas Rebsorten—300 Sorten und Ihre Weine, 3rd ed.; Verlag Eugen Ulmer: Stuttgart, Germany, 2011. [Google Scholar]
  22. Boulton, R.B.; Singleton, V.L.; Bisson, L.F.; Kunkee, R.E. Principles and Practices of Winemaking; Springer: New York, NY, USA, 1999. [Google Scholar]
  23. Fischer, U.; Strasser, M.; Gutzler, K. Impact of fermentation technology on the phenolic and volatile composition of German red wines. Int. J. Food Sci. Technol. 2000, 35, 81–94. [Google Scholar] [CrossRef]
  24. Nieuwoudt, H.H.; Prior, B.A.; Pretorius, I.S.; Bauer, F.F. Glycerol in South African Table Winess: An Assessment of its Relationship to Wine Quality. S. Afr. J. Enol. Vitic. 2002, 23, 22–23. [Google Scholar]
  25. Komes, D.; Ulrich, D.; Lovric, T. Characterization of odor-active compounds in Croatian Rhine Riesling wine, subregion Zagorje. Eur. Food Res. Technol. 2006, 222, 1–7. [Google Scholar] [CrossRef]
  26. Dennis, E.G.; Keyzers, R.A.; Kalua, C.M.; Maffei, S.M.; Nicholson, E.L.; Boss, P.K. Grape Contribution to Wine Aroma: Production of Hexyl Acetate, Octyl Acetate, and Benzyl Acetate during Yeast Fermentation Is Dependent upon Precursors in the Must. J. Agric. Food Chem. 2012, 60, 2638–2646. [Google Scholar] [CrossRef] [PubMed]
  27. Sener, H.; Yildirim, H.K. Influence of different maceration time and temperatures on total phenols, colour and sensory properties of Cabernet Sauvignon wines. Food Sci. Technol. Int. 2013, 19, 523–533. [Google Scholar] [CrossRef] [PubMed]
  28. Moreno-Perez, A.; Vila-Lopez, R.; Fernandez-Fernandez, J.I.; Martinez-Cutillas, A.; Gil-Munoz, R. Influence of cold pre-fermentation treatments on the major volatile compounds of three wine varieties. Food Chem. 2013, 139, 770–776. [Google Scholar] [CrossRef] [PubMed]
  29. Bakker, J.; Clarke, R.J. Volatile Components. In Wine Flavour Chemistry; Bakker, J., Clarke, R.J., Eds.; Wiley-Blackwell: Chichester, UK, 2011; pp. 155–238. [Google Scholar]
  30. Bell, S.J.; Henschke, P.A. Implications of nitrogen nutrition for grapes, fermentation and wine. Aust. J. Grape Wine Res. 2005, 11, 242–295. [Google Scholar] [CrossRef]
  31. Slegers, A.; Angers, P.; Ouellet, E.; Truchon, T.; Pedneault, K. Volatile compounds from grape skin, juice and wine from five interspecific hybrid grape cultivars grown in Quebec (Canada) for wine production. Molecules 2015, 20, 10980–11016. [Google Scholar] [CrossRef] [PubMed]
  32. Vilanova, M.; Ugliano, M.; Varela, C.; Siebert, T.; Pretorius, I.S.; Henschke, P.A. Assimilable nitrogen utilisation and production of volatile and non-volatile compounds in chemically defined medium by saccharomyces cerevisiae wine yeasts. Appl. Microbiol. Biotechnol. 2007, 77, 145–157. [Google Scholar] [CrossRef] [PubMed]
  33. Sefton, M.A.; Francis, I.L.; Williams, P.J. The volatile composition of chardonnay juices—A study by flavor precursor analysis. Am. J. Enol. Vitic. 1993, 44, 359–370. [Google Scholar]
  34. Campo, E.; Ferreira, V.; Escudero, A.; Marques, J.C.; Cacho, J. Quantitative gas chromatography-olfactometry and chemical quantitative study of the aroma of four Madeira wines. Anal. Chim. Acta 2006, 563, 180–187. [Google Scholar] [CrossRef]
  35. Genovese, A.; Gambuti, A.; Piombino, P.; Moio, L. Sensory properties and aroma compounds of sweet Fiano wine. Food Chem. 2007, 103, 1228–1236. [Google Scholar] [CrossRef]
  36. Lopez-Tamames, E.; CarroMarino, N.; Gunata, Y.Z.; Sapis, C.; Baumes, R.; Bayonove, C. Potential aroma in several varieties of spanish grapes. J. Agric. Food Chem. 1997, 45, 1729–1735. [Google Scholar] [CrossRef]
  37. Mateo, J.J.; Jimenez, M. Monoterpenes in grape juice and wines. J. Chromatogr. A 2000, 881, 557–567. [Google Scholar] [CrossRef]
  38. Sefton, M.A.; Skouroumounis, G.K.; Elsey, G.M.; Taylor, D.K. Occurrence, sensory impact, formation, and fate of damascenone in grapes, wines, and other foods and beverages. J. Agric. Food Chem. 2011, 59, 9717–9746. [Google Scholar] [CrossRef] [PubMed]
  39. Bianchi, F.; Careri, M.; Mangia, A.; Musci, M. Retention indices in the analysis of food aroma volatile compounds in temperature-programmed gas chromatography: Database creation and evaluation of precision and robustness. J. Sep. Sci. 2007, 30, 563–572. [Google Scholar] [CrossRef] [PubMed]
  40. Etiévant, P.X. Wine. In Volatile Compounds in Foods and Beverages, 1st ed.; Maarse, H., Ed.; Marcel Dekker: New York, NY, USA, 1991; pp. 483–546. [Google Scholar]
  41. Guth, H. Comparison of different white wine varieties in odor profiles by instrumental analysis and sensory studies. Abstr. Pap. Am. Chem. Soc. 1997, 45, 3027–3032. [Google Scholar]
  42. Takeoka, G.R.; Buttery, R.G.; Turnbaugh, J.G.; Benson, M. Odor Thresholds of Various Branched Esters. LWT Food Sci. Technol. 1995, 28, 153–156. [Google Scholar] [CrossRef]
  43. Gómez-Míguez, M.J.; Cacho, J.F.; Ferreira, V.; Vicario, I.M.; Heredia, F.J. Volatile components of Zalema white wines. Food Chem. 2007, 100, 1464–1473. [Google Scholar] [CrossRef]
  44. Tao, Y.S.; Zhang, L. Intensity prediction of typical aroma characters of cabernet sauvignon wine in Changli County (China). LWT Food Sci. Technol. 2010, 43, 1550–1556. [Google Scholar] [CrossRef]
  45. Moyano, L.; Zea, L.; Moreno, J.; Medina, M. Analytical study of aromatic series in sherry wines subjected to biological aging. J. Agric. Food Chem. 2002, 50, 7356–7361. [Google Scholar] [CrossRef] [PubMed]
  46. Ferreira, V.; Ortin, N.; Escudero, A.; Lopez, R.; Cacho, J. Chemical characterization of the aroma of Grenache rose wines: Aroma extract dilution analysis, quantitative determination, and sensory reconstitution studies. J. Agric. Food Chem. 2002, 50, 4048–4054. [Google Scholar] [CrossRef] [PubMed]
  47. Buttery, R.G.; Seifert, R.M.; Ling, L.C.; Soderstrom, E.L.; Ogawa, J.M.; Turnbaugh, J.G. Additional Aroma Components of Honeydew Melon. J. Agric. Food Chem. 1982, 30, 1208–1211. [Google Scholar] [CrossRef]
  48. Takeoka, G.R.; Buttery, R.G.; Teranishi, R.; Flath, R.A.; Guntert, M. Identification of Additional Pineapple Volatiles. J. Agric. Food Chem. 1991, 39, 1848–1851. [Google Scholar] [CrossRef]
  49. Franco, M.; Peinado, R.A.; Medina, M.; Moreno, J. Off-vine grape drying effect on volatile compounds and aromatic series in must from Pedro Ximenez grape variety. J. Agric. Food Chem. 2004, 52, 3905–3910. [Google Scholar] [CrossRef] [PubMed]
  50. Ahmed, E.M.; Dennison, R.A.; Dougherty, R.H.; Shaw, P.E. Flavor and Odor Thresholds in Water of Selected Orange Juice Components. J. Agric. Food Chem. 1978, 26, 187–191. [Google Scholar] [CrossRef]
  51. Cullere, L.; Escudero, A.; Cacho, J.; Ferreira, V. Gas chromatography-olfactometry and chemical quantitative study of the aroma of six premium quality Spanish aged red wines. J. Agric. Food Chem. 2004, 52, 1653–1660. [Google Scholar] [CrossRef] [PubMed]
  52. Moreira, N.; Guedes de Pinho, P.; Santos, C.; Vasconcelos, I. Volatile sulphur compounds composition of monovarietal white wines. Food Chem. 2010, 123, 1198–1203. [Google Scholar] [CrossRef]
  53. Vilanova, M.; Genisheva, Z.; Masa, A.; Oliveira, J.M. Correlation between volatile composition and sensory properties in Spanish Albarino wines. Microchem. J. 2010, 95, 240–246. [Google Scholar] [CrossRef] [Green Version]
  54. Campo, E.; Ferreira, V.; Escudero, A.; Cacho, J. Prediction of the wine sensory properties related to grape variety from dynamic-headspace gas chromatography-olfactometry data. J. Agric. Food Chem. 2005, 53, 5682–5690. [Google Scholar] [CrossRef] [PubMed]
  55. Falque, E.; Fernandez, E.; Dubourdieu, D. Differentiation of white wines by their aromatic index. Talanta 2001, 54, 271–281. [Google Scholar] [CrossRef]
  56. Vilanova, M.; Escudero, A.; Grana, M.; Cacho, J. Volatile composition and sensory properties of North West Spain white wines. Food Res. Int. 2013, 54, 562–568. [Google Scholar] [CrossRef]
  57. Allen, M.S.; Lacey, M.J.; Boyd, S.J. Methoxypyrazines in Red Wines—Occurrence of 2-Methoxy-3-(1-Methylethyl)Pyrazine. J. Agric. Food Chem. 1995, 43, 769–772. [Google Scholar] [CrossRef]
  58. Allen, M.S.; Lacey, M.J.; Boyd, S. Determination of Methoxypyrazines in Red Wines by Stable-Isotope Dilution Gas-Chromatography Mass-Spectrometry. J. Agric. Food Chem. 1994, 42, 1734–1738. [Google Scholar] [CrossRef]
  59. Sala, C.; Mestres, M.; Marti, M.P.; Busto, O.; Guasch, J. Headspace solid-phase microextraction analysis of 3-alkyl-2-methoxypyrazines in wines. J. Chromatogr. A 2002, 953, 1–6. [Google Scholar] [CrossRef]
  60. Hein, K.; Ebeler, S.E.; Heymann, H. Perception of fruity and vegetative aromas in red wine. J. Sens. Stud. 2009, 24, 441–455. [Google Scholar] [CrossRef]
  61. Hoff, S.; Damgaard, J.; Petersen, M.A.; Jespersen, B.M.; Andersen, M.L.; Lund, M.N. Influence of Barley Varieties on Wort Quality and Performance. J. Agric. Food Chem. 2013, 61, 1968–1976. [Google Scholar] [CrossRef] [PubMed]
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Zhang, S.; Petersen, M.A.; Liu, J.; Toldam-Andersen, T.B. Influence of Pre-Fermentation Treatments on Wine Volatile and Sensory Profile of the New Disease Tolerant Cultivar Solaris. Molecules 2015, 20, 21609-21625. https://doi.org/10.3390/molecules201219791

AMA Style

Zhang S, Petersen MA, Liu J, Toldam-Andersen TB. Influence of Pre-Fermentation Treatments on Wine Volatile and Sensory Profile of the New Disease Tolerant Cultivar Solaris. Molecules. 2015; 20(12):21609-21625. https://doi.org/10.3390/molecules201219791

Chicago/Turabian Style

Zhang, Shujuan, Mikael Agerlin Petersen, Jing Liu, and Torben Bo Toldam-Andersen. 2015. "Influence of Pre-Fermentation Treatments on Wine Volatile and Sensory Profile of the New Disease Tolerant Cultivar Solaris" Molecules 20, no. 12: 21609-21625. https://doi.org/10.3390/molecules201219791

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