Fruity Character Research Articles

Mead production: effect of nitrogen supplementation on growth, fermentation profile and aroma formation by yeasts in mead fermentation

Mead is an alcoholic beverage, produced since ancient times, resulting from an alcoholic fermentation of diluted honey by yeasts. When it is produced in a traditional manner, mead producers can encounter several problems related to a lack of essential nutrients, such as available nitrogen. Thus, the aim of this study was to evaluate the effect of nitrogen addition to honey-must on the fermentation performance of two Saccharomyces cerevisiae wine yeasts, QA23 and ICV D47, as well as on the mead composition and production of volatile aroma compounds. A portion of honey-must was supplemented with diammonium phosphate (DAP) to achieve the nitrogen concentration required by yeast to complete alcoholic fermentation. The supplementation with DAP reduced the fermentation length to around 7 days, but not all sugars were fully consumed, suggesting that other factors could be interfering with yeast growth. For both yeasts the specific growth rate and final biomass were higher in musts supplemented with DAP. Mead final composition was similar under the two experimental conditions. Analysis of the volatile profile revealed that the concentrations of the volatile fatty acids and volatile phenols were higher in meads supplemented with DAP. The concentrations of ethyl hexanoate, ethyl octanoate and isoamyl acetate were above their perception threshold and were higher in meads supplemented with DAP, which could contribute to the enhancement of the fruity character. This study could be useful for the optimization of mead production and quality improvement. Copyright © 2015 The Institute of Brewing & Distilling

Identification of sensory attributes that drive the likeability of Korean rice wines by American panelists. [Corrected

Six commercial Korean rice wines were described their sensory profiles by trained American panelists, and assessed acceptances by American subjects to identify the drivers of liking and disliking factors. Thirteen statistically different descriptive attributes were defined for Korean rice wines: aromas (apple, pear, earthy, peach, nutty, yeasty, honey), flavor (yeasty, nutty), taste (sweet, sour, bitter), and aftertaste (apricot). Samples A and F were characterized as sweet taste and fruity attributes, and sample C was characterized as being pear flavor and bitter taste. Sample B exhibited a strong earthy aroma, determined as the aroma of ginseng. The American subjects could not identify ginseng aroma due to their lack of experience in ginseng. Samples D and E were described as nutty and yeasty. In consumer test, consumer preference was skewed to sample A, for which the consumer preference revolved around the sweet, sour, and fruity characteristics of the sample by the principal component analysis. Few consumers expressed preference toward samples D and E, as evidenced by the lowest consumer acceptance ratings. Partial least squares regression revealed that the key liking factors of Korean rice wines were sweet, sour, and apricot flavors. Fruity characteristics (peach, apple, and pear) were also positively correlated with overall acceptance. The key disliking factors were yeasty and nutty characteristics. American subjects regarded Korean rice wine as belonging to the wine category, prompting them to grant the highest rank to sample A, which has similar characteristics to semisweet white wine.

Modulation of chemical and sensory characteristics of red wine from Mencía by using indigenous <em>Saccharomyces cerevisiae</em> yeast strains

<p style="text-align: justify;"><strong>Aim</strong>: To evaluate the influence of native <em>Saccharomyces cerevisiae </em>strains in red wines from <em>Vitis vinifera</em> cv. Mencía: fermentative ability, inoculation success, and sensory and chemical characteristics of wines.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Indigenous yeast strains (Sc5, Sc11, Sc21 and Sc24) were inoculated in grape musts and their inoculation success was followed by mtDNA-RFLP (mitochondrial DNA-restriction fragment length polymorphism) at different stages of fermentation. The results showed that the added yeast strains fermented in co-dominance with a resident strain, which also controlled the spontaneous processes. Chemical analysis of basic wine parameters using official methodologies showed significant differences among wines for alcohol degree and volatile acidity. Fermentative aroma compounds were determined by gas chromatography. Wines made with different yeast strains varied in higher alcohols, ethyl ester, 2-phenylethanol, ethyl lactate and acetoin content. Sensory analysis indicated that wine from strain Sc24 had the best overall score, whereas that from strain Sc11 achieved the highest scores for colour intensity, structure and fruity character.</p><p style="text-align: justify;"><strong>Conclusions</strong>: The application of selected <em>S. cerevisiae</em> strains allowed us to obtain differentiated wines from both the chemical and sensory points of view.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: The results confirmed that indigenous yeasts can be used to elaborate singular wines and may constitute a useful tool to diversify Mencía wines.</p>

Kiwi spirits with stronger floral and fruity characters were obtained with a packed column distillation system

The impact of the distillation system and yeast strain on the chemical and aromatic profile of kiwi spirits was investigated. Three fermentations of kiwi fruits were carried out, two with selected yeasts (KL1 and KL2) and one spontaneous (KL3). The obtained kiwi wines were distilled using two distillation systems (Charentais alembic and packed column), and the resulting spirits were analysed by direct injection gas chromatography. Kiwi spirits obtained with the packed column had the highest concentrations of esters C6–C10 and monoterpenols, while the alembic spirits had the highest concentrations of ethyl acetate, methyl acetate and higher alcohols. Three principal components derived from the chemical composition data explained 96.6% of the variance. Principal component 1 differentiated alembic from packed column distillates, principal component 2 distinguished KL3 spirits and principal component 3 distinguished KL1 spirits. Kiwi spirits distilled with the packed column were preferred by consumers. The predominant sensory descriptors in the packed column kiwi spirits were floral, fruity and spicy, while burnt/smoky and pungent were the principal aroma descriptors in alembic spirits. Moreover, significantly higher ethanol yields and ethanol strengths were obtained with the packed column distillation system. The observed influence of the yeast strains on preference and ethanol yields was minor. Copyright © 2014 The Institute of Brewing & Distilling

Acetate ester production by Chinese yellow rice wine yeast overexpressing the alcohol acetyltransferase-encoding gene ATF2.

Acetate ester, which are produced by fermenting yeast cells in an enzyme-catalyzed intracellular reaction, are responsible for the fruity character of fermented alcoholic beverages such as Chinese yellow rice wine. Alcohol acetyltransferase (AATase) is currently believed to be the key enzyme responsible for the production of acetate ester. In order to determine the precise role of the ATF2 gene in acetate ester production, an ATF2 gene encoding a type of AATase was overexpressed and the ability of the mutant to form acetate esters (including ethyl acetate, isoamyl acetate, and isobutyl acetate) was investigated. The results showed that after 5 days of fermentation, the concentrations of ethyl acetate, isoamyl acetate, and isobutyl acetate in yellow rice wines fermented with EY2 (pUC-PIA2K) increased to 137.79 mg/L (an approximate 4.9-fold increase relative to the parent cell RY1), 26.68 mg/L, and 7.60 mg/L, respectively. This study confirms that the ATF2 gene plays an important role in the production of acetate ester production during Chinese yellow rice wine fermentation, thereby offering prospects for the development of yellow rice wine yeast starter strains with optimized ester-producing capabilities.

Effect of Saccharomyces cerevisiae cells immobilisation on mead production

Mead is a traditional alcoholic beverage obtained by the fermentation of diluted honey performed by yeasts. In this work the potential of application of immobilised yeast cells on single-layer Ca-alginate or double-layer alginate–chitosan for mead production was assessed for the first time. The meads produced either with entrapped or free cells were evaluated in terms of quality and aroma profile. The immobilisation procedure had no adverse effect on cell viability, since minor differences were found in fermentation kinetics among the strains and immobilisation systems. The double-layer alginate-chitosan had no advantage compared with the single-layer Ca-alginate, as the number of free cells in the medium, resulting from cell leakage, was similar. Although meads obtained with entrapped yeast cells presented less ethanol and glycerol and more acetic acid, it exhibited larger amounts of volatile compounds. Immobilised cells produced meads with more compounds with fruity characteristics, such as ethyl octanoate and ethyl hexanoate; however the concentrations of undesirable compounds in such meads were also higher. The effect of immobilisation on the aroma profile was important, but the strain contribution was also of major importance. Thus, the sensory analysis of final product gives an important insight on the overall quality.

Sensory and instrumental analysis of medium and long shelf-life Charentais cantaloupe melons (Cucumis melo L.) harvested at different maturities

The flavour profiles of two genotypes of Charentais cantaloupe melons (medium shelf-life and long shelf-life), harvested at two distinct maturities (immature and mature fruit), were investigated. Dynamic headspace extraction (DHE), solid-phase extraction (SPE), gas chromatography–mass spectrometry (GC–MS) and gas chromatography–olfactometry/mass spectrometry (GC–O/MS) were used to determine volatile and semi-volatile compounds. Qualitative descriptive analysis (QDA) was used to assess the organoleptic impact of the different melons and the sensory data were correlated with the chemical analysis. There were significant, consistent and substantial differences between the mature and immature fruit for the medium shelf-life genotype, the less mature giving a green, cucumber character and lacking the sweet, fruity character of the mature fruit. However, maturity at harvest had a much smaller impact on the long shelf-life melons and fewer differences were detected. These long shelf-life melons tasted sweet, but lacked fruity flavours, instead exhibiting a musty, earthy character.

Analysis and Sensory Evaluation of Gooseberry (Ribes uva crispa L.) Volatiles

Volatiles of gooseberries (Ribes uva cripsa L.) were isolated by means of vacuum-headspace-extraction, and the obtained concentrates were analyzed via capillary gas chromatography-mass spectrometry. To ensure the quantitation of highly volatile compounds, headspace analysis was additionally performed on selected batches. C₆-components (e.g., (Z)-hex-3-enal, (E)-hex-2-enal), derived from lipid oxidation, and short-chain esters (e.g., ethyl acetate, methyl butanoate, ethyl butanoate) turned out to be the major compound classes in the fresh fruit. The compositional variability was demonstrated by analyzing several gooseberry varieties at different stages of ripeness. The contributions of volatiles to the gooseberry aroma were assessed by using gas chromatography-olfactometry in combination with aroma extract dilution analysis and calculation of odor activity values. C₆-components and esters were shown to be responsible for the green and fruity character of fresh gooseberries.

Effect of foliar urea fertilisation on volatile compounds in Tempranillo wine

The impact of fertilisation with three doses of foliar urea (0, 2 and 4 kg N ha(-1)) on the concentration of volatile compounds in Tempranillo wine was studied. The total concentration of alcohols decreased with the application of urea. The concentrations of ethyl hexanoate, ethyl octanoate and ethyl decanoate were highest in the wine resulting from the 4 kg N ha(-1) urea treatment. Fatty acids showed different individual responses to the application of urea. Sensory analysis indicated that the wines from urea-treated grapevines had higher aroma intensity and a more fruity character than the control wine. It may be concluded that foliar urea fertilisation shows itself to be efficient in small doses as a complement to soil fertilisation to improve wine aroma.

Fruit Quality Measures from a Historical Trial of University of Florida Strawberry Cultivars

The strawberry breeding program of the University of Florida develops varieties that are highly adapted to west-central Florida, where approximately 8,800 acres of strawberries were grown during the 2009–10 season. In order to gain insight into breeding progress over time, two advanced selections and ten released cultivars, from Florida Belle (1975) to Florida Radiance (2008), were compared for various fruit quality traits. Cultivars and selections were arranged in a randomized complete block design at each of two locations (Balm, FL and Dover, FL). Fruit size varied dramatically with a minimum average weight of 16.2 g for ‘Dover’ (1979) and a maximum of 30.8 g for ‘Elyana’ (2008). Regression of average fruit weight on year of release showed an average gain in fruit size of 0.26 g/yr (R2 = 0.44). Improvements in fruit uniformity were also apparent, but gains for internal flesh color were not sustained. There was wide seasonal variability in sugars (sucrose, glucose, fructose, Brix) and acids (citric, malic, and titratable acidity); March tended to produce fruit with lower sugars. Sugars were highest in February while acids were highest in January. Also, correlations were found between sugars and volatiles having fruity and strawberry characters. Comparison of chemical data with sensory data from related studies indicates that instrumental measures, particularly for SSC/TA, could aid in breeding for improved flavor.

First Evidence of the Production of Odorant Polyfunctional Thiols by Bottle Refermentation

Bottle refermentation, which confers effervescence and resistance against infection and oxidation to beers, has also long been known to affect the fruity character imparted by esters. Yet it is recognized to improve the flavor perception, first by reducing stale aldehydes (trans-2-nonenal, 3-methylthiopropionaldehyde, etc.) to low-odorant alcohols, and also by bringing new pleasant odors. In this work, the polyfunctional thiol contents of a beer subjected or not to bottle refermentation were compared. A trained panel detected a strong organoleptic impact of bottle refermentation. Specific pHMB thiol extraction was applied and the extracts were analyzed by GC-MS, GC-PFPD, and GC-olfactometry (AEDA). Many sulfanylalkylalcohols, sulfanylalkylacetates, and sulfanylalkylcarbonyls were shown to be produced during the refermentation process, especially after 3 weeks. Among them, the hoppy 1-sulfanyl-3-methyl-2-butene was still perceived at the sniffing port after diluting the extract by a factor of 32,768. The major thiol, 2-sulfanylethyl acetate, reached 10 μg/L. As shown by spiking deuterated cysteine before bottle refermentation, the Ehrlich pathway revealed still efficient in the bottle. Most of the other identified polyfunctional thiols shared a common beta-sulfanyl structure, which lead us to suspect that hop cysteine adducts might be hydrolyzed by yeast-derived lyases. The spiking of 5 and 10 mg/L of S-3-(1-hydroxyhexyl)cysteine confirmed the ability of yeast to release free thiols through bottle refermentation. Therefore, a better control of the refermentation process requires both an excellent control of yeast (Ehrlich pathway and β-lyase activity) and strict selection of the hop variety (level of cysteine adducts).

Changes in the Sensory Characteristics of Mango Cultivars during the Production of Mango Purée and Sorbet

The effects of processing on the flavor and texture properties of 4 mango cultivars available in the U.S. were studied. Descriptive panelists evaluated fresh mango, mango purée, and mango sorbet prepared from each cultivar. Purées were made by pulverizing mango flesh, passing it through a china cap, and heating it to 85 °C for 15 s. To prepare the sorbets, purées were diluted with water (1:1), sucrose was added to increase the total soluble solids (TSS) to 32 ± 2 °Brix, and bases were frozen in a batch-type ice cream freezer. Processing fresh mangoes into mango purée generally decreased fruity character and mango identity and led to the appearance of a cooked note. Many of the flavor distinctions among cultivars carried over from fresh to purée samples, but much of the texture variation was lost. Thermal processing had differing effects on the flavor of the cultivars, and therefore, results suggest that mango cultivars for purées should be selected based on properties after thermal treatment. Processing purées into sorbets minimized flavor variation among cultivars, although Tommy Atkins sorbet was relatively high in green and green-viney character and low in caramelized flavor compared to the other cultivars in sorbet. Based on the current study only very distinct flavor properties of mango cultivars may carry over to sorbets. Findings from the present study will help mango purée and sorbet manufacturers select appropriate cultivars for their products by understanding the transformation that mango undergoes as it is processed into mango purée and subsequently to mango sorbet.

Climatic factors directly impact the volatile organic compound fingerprint in green Arabica coffee bean as well as coffee beverage quality

Coffee grown at high elevations fetches a better price than that grown in lowland regions. This study was aimed at determining whether climatic conditions during bean development affected sensory perception of the coffee beverage and combinations of volatile compounds in green coffee. Green coffee samples from 16 plots representative of the broad range of climatic variations in Réunion Island were compared by sensory analysis. Volatiles were extracted by solid phase micro-extraction and the volatile compounds were analysed by GC–MS. The results revealed that, among the climatic factors, the mean air temperature during seed development greatly influenced the sensory profile. Positive quality attributes such as acidity, fruity character and flavour quality were correlated and typical of coffees produced at cool climates. Two volatile compounds (ethanal and acetone) were identified as indicators of these cool temperatures. Among detected volatiles, most of the alcohols, aldehydes, hydrocarbons and ketones appeared to be positively linked to elevated temperatures and high solar radiation, while the sensory profiles displayed major defects (i.e. green, earthy flavour). Two alcohols (butan-1,3-diol and butan-2,3-diol) were closely correlated with a reduction in aromatic quality, acidity and an increase in earthy and green flavours. We assumed that high temperatures induce accumulation of these compounds in green coffee, and would be detected as off-flavours, even after roasting. Climate change, which generally involves a substantial increase in average temperatures in mountainous tropical regions, could be expected to have a negative impact on coffee quality.

Distribution and Organoleptic Impact of Ethyl 2-Hydroxy-4-methylpentanoate Enantiomers in Wine

The enantiomers of ethyl 2-hydroxy-4-methylpentanoate (ethyl dl-leucate) were assayed in several wines using chiral gas chromatography (γ-cyclodextrin). Analyses of 55 commercial wines from various vintages and origins revealed different distributions. Generally, white wines presented only the R form, whereas red wines contained both enantiomers, in various ratios according to aging. The highest levels of the S form were found in the oldest samples. The R/S average enantiomeric ratio of this compound in red wine was approximately 95:5 with an average total concentration of ∼400 μg/L. The olfactory threshold of R-ethyl 2-hydroxy-4-methylpentanoate (126 μg/L) in hydroalcoholic solution was almost twice that of the S form (55 μg/L). The olfactory threshold of a mixture of R- and S-ethyl 2-hydroxy-4-ethylpentanoate (95:5, m/m) in hydroalcoholic solution was 51μg/L, suggesting that both enantiomeric forms contribute to perception of this compound in wine, resulting in a synergistic effect. Both enantiomers have quite similar aromatic nuances. Sensory analysis was employed to demonstrate a synergistic effect of this ethyl ester on the perception of fruity aromas in wine: in hydroalcoholic solution supplemented with R- or S-ethyl 2-hydroxy-4-methylpentanoate or a mixture of the R and S forms (95:5, m/m) at their average concentrations in red wines, fruity character was perceived at concentrations 2.2, 4.5, and 2.5 times lower, respectively, than in hydroalcoholic solution alone. Sensory profiles of aromatic reconstitutions, using HPLC fruity fractions, highlighted the contribution of this compound to blackberry fruit and fresh fruit descriptors.

Effect of storage temperature on the chemical composition and sensory profile of Sauvignon Blanc wines

Background and Aims: Most white wines lose fresh and fruity characteristics, associated with volatile esters, during ageing in the bottle. A higher storage temperature accelerates these changes. The aim of this study was to examine the influence of storage temperature on the chemical and sensory properties of Sauvignon Blanc wines. Methods and Results: Three commercially bottled Sauvignon Blanc wines from the 2008 and 2009 vintages were stored at 5, 10, 18°C and at room temperature for 12 months. Wines stored at warmer temperatures (18°C and room temperature) contained lower concentrations of acetate esters, including the prominent varietal thiol 3MHA, and ethyl esters of fatty acids, than the wines stored at cooler temperatures (5 and 10°C). A warmer temperature accelerated the rate of ester hydrolysis. Conversely, the concentrations of ethyl esters of branched acids were higher in wines stored at the warmer temperatures. The sensory profile of the wines was assessed after 12 months for the two 2008 wines and after 8 months for the 2009 wine. The wines stored at cooler temperatures were characterised by higher fruity and fresh vegetal aromas, whereas the wines stored at warmer temperatures exhibited the opposite sensory profile, with dominant woody/smoky/oaky, buttery, flinty and canned asparagus notes. Conclusions: These results indicate that temperature-dependent hydrolysis processes are critical for Sauvignon Blanc aroma stability during the first year in the bottle. Significance of the Study: Cool storage temperature conditions can significantly increase the shelf-life of Sauvignon Blanc wines by preserving their fruity and fresh green characters.

Discrimination of brazilian red varietal wines according to their sensory descriptors

The purpose of this paper was to establish the sensory characteristics of wines made from old and newly introduced red grape varieties. To attain this objective, 16 Brazilian red varietal wines were evaluated by a sensory panel of enologists who assessed wines according to their aroma and flavor descriptors. A 90 mm unstructured scale was used to quantify the intensity of 26 descriptors, which were analyzed by means of the Principal Component Analysis (PCA). The PCA showed that three important components represented 74.11% of the total variation. PC 1 discriminated Tempranillo, Marselan and Ruby Cabernet wines, with Tempranillo being characterized by its equilibrium, quality, harmony, persistence and body, as well as by, fruity, spicy and oaky characters. The other two varietals were defined by vegetal, oaky and salty characteristics; PC 2 discriminated Pinot Noir, Sangiovese, Cabernet Sauvignon and Arinarnoa, where Pinot Noir was characterized by its floral flavor; PC 3 discriminated only Malbec, which had weak, floral and fruity characteristics. The other varietal wines did not show important discriminating effects.

CHANGES IN VOLATILE PRODUCTION AND SENSORY QUALITY OF ACTINIDIA ARGUTA FRUIT DURING FRUIT MATURATION

Fruit of Actinidia arguta ('Hortgem Tahi', 'Hortgem Rua', 'Hortgem Toru' and 'Hortgem Wha') were evaluated at different softening stages during ripening. The volatiles released from the fruit and their sensory qualities, as assessed by a trained taste panel, were compared with those of A. deliciosa 'Hayward' and A. chinensis 'Hort16A' fruit. Gas chromatography-mass spectrometry (GC-MS) data indicated that each species had different characteristic volatiles. Straight chain aldehydes and esters were the dominant volatiles detected during the ripening of A. arguta fruit. As in 'Hayward' fruit, the total percentages of (E)-2-hexenal and hexanal, which impart green characteristics, decreased as the fruit softened. Butanoates (fruity characteristics) detected in the fruit increased as fruit firmness decreased. However, in the A. arguta fruit, higher levels of terpenes and aldehydes were detected. With fruit softening, sensory perception of acidity decreased but typical kiwifruit odour and flavour intensity (ethyl butanoate) increased. More tropical aroma and a slightly bitter skin taste were also noted by panellists for all tested fruit.

Identifying the Chemical Composition Related to the Distinct Aroma Characteristics of New Zealand Sauvignon blanc Wines

A comprehensive set of aroma compounds was quantified in 79 Sauvignon blanc wines from different international producers. Emphasis was given to understanding the chemical differences that can explain the unique character of Marlborough Sauvignon blanc. Quantification revealed the potential importance of several volatile compounds in addition to the polyfunctional mercaptans and methoxypyrazines already known to be important to the aroma of Sauvignon blanc wines. Multivariate statistical approaches, including canonical variate analysis, classification tree and partial least square analysis, established correlations between the chemical and the sensory profiles of the wines. A significant role of 3-mercaptohexyl acetate and 3-mercaptohexanol in the unique tropical, fruity character of Marlborough Sauvignon blanc wines was demonstrated, together with important variations in their concentrations, pointing to different styles even within the Marlborough wines.

Malolactic fermentation of Tempranillo wine: contribution of the lactic acid bacteria inoculation to sensory quality and chemical composition

Malolactic fermentation (MLF) of Tempranillo Rioja wines (Spain) inoculated with two lactic acid bacteria (LAB) strains were studied and compared with spontaneous MLF. Inoculation with selected Oenococcus oeni lyophila shortened MLF duration up to 19days and lead to wines with more fresh and fruity characters, especially when implantation was 100%. We demonstrated modifications in the concentration of volatile and nitrogenous compounds and a good correlation between analytical and sensory attributes was also noted. In addition, the low initial amino acid concentration and the consumption of these compounds by the inoculated yeast strain during alcoholic fermentation resulted in wines with very low biogenic amines levels (under 3.75mgL -1) after MLF and 3month storage period in all cases. The results showed the significance of choose the most suitable starter to elaborate quality wines and suggest the control of amino acid content in must and wine to prevent the formation of biogenic amines. © 2011 The Authors. International Journal of Food Science and Technology © 2011 Institute of Food Science and Technology.

Contribution of grape skin and fermentation microorganisms to the development of red- and black-berry aroma in Merlot wines

<p style="text-align: justify;"><strong>Aim</strong>: The aim of this study was to elucidate how an initially neutral Merlot must resulted in a wine with characteristic aromas of red- and black-berry fruit, focusing on the respective contributions of yeast metabolism together with grape juice, pulp, and skins.</p><p style="text-align: justify;"><strong>Methods and Results</strong>: Sensory analyses were performed on Merlot grape skin maceration models, based on observations in the winery. Initial findings revealed that strong fruity nuances appeared during pre-fermentation maceration. In the maceration models used, the development of aroma of red- and black-berry fruit systematically paralleled the growth of the yeast population. The respective roles of grape skins and yeasts were investigated throughout the alcoholic fermentation of model musts with addition of Merlot skins or Merlot skin extract in ethanol. The aromatic nuances revealed by alcoholic fermentation in a must alone had no specific white-, rosé-, or red-wine character. In contrast, wines made by microvinification with grape skins and/or grape skin extract in ethanol had a clear, intense aroma of red- and black-berry. Microvinification with both Merlot skin extract and grape skins revealed the most intense fruity character.</p><p style="text-align: justify;"><strong>Conclusions</strong>: Inodorous skin constituents produced a specific aroma of red- and black-berry fruit after alcoholic fermentation by yeast. The physical presence of grape skins during fermentation enhanced the intensity of the fruity nuances obtained.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: The study established, for the first time, the existence of inodorous constituents in Merlot grape skins, extractible by ethanol and transformed by yeasts to produce a specific aroma of red- and black-berry fruit in the finished wines.</p>