A comparative study of the volatile content of Mencía wines obtained using different pre-fermentative maceration techniques

Comprehensive Analysis of Physicochemical Properties and Volatile Compounds in Different Strawberry Wines under Various Pre-Treatments

Pre-fermentation treatment has an important impact on the color, aroma, taste, and other characteristics of fruit wine. To discover suitable pre-treatment techniques and conditions that yield strawberry wine of excellent quality, the influences of juice fermentation, pulp maceration, thermovinification, and enzymatic hydrolysis pre-treatments on the basic chemical composition, color, antioxidant capacity, and volatile organic compounds in strawberry wines were investigated. The results showed that the color, antioxidant properties, and volatile aroma of strawberry wines fermented with juice were different from those with pulp. Strawberry wines fermented from juice after 50 °C maceration had more desirable qualities, such as less methanol content (72.43 ± 2.14 mg/L) compared with pulp-fermented wines (88.16 ± 7.52 mg/L) and enzymatic maceration wines (136.72 ± 11.5 mg/L); higher total phenolic content (21.78%) and total flavonoid content (13.02%); enhanced DPPH (17.36%) and ABTS (27.55%) free radical scavenging activities; richer essential terpenoids and fatty acid ethyl esters, such as linalool (11.28%), ethyl hexanoate (14.41%), ethyl octanoate (17.12%), ethyl decanoate (32.49%), and ethyl 9-decenoate (60.64%); pleasant floral and fruity notes compared with juice-fermented wines macerated at normal temperatures; and a lighter color. Overall, juice thermovinification at 50 °C is a potential pre-treatment technique to enhance the nutrition and aroma of strawberry wine.

A two-run heart-cut multidimensional gas chromatography method using flame ionization and mass spectrometry for automated and robust determination of nearly complete wine aroma-volatile profiles

A quantitative analytical method capable of determining the concentrations of 81 aroma-relevant wine volatiles covering nine orders of magnitude was developed and validated in this study. The method is based on stir bar sorptive extraction (SBSE) of 200 μL of wine diluted with 1.8 mL NaCl brine with pH 3.5. Volatiles thermally desorbed from the stir bars were separated in two runs in a heart-cut multidimensional gas chromatographic system and quantified using either a flame ionization detector (FID) in the first dimension (27 aroma compounds) or a mass spectrometer in the second dimension (54 aroma compounds, transferred to 22 cuts). Typical limits of compound detection lay around 0.02 mg/L by FID or ranged from 0.001 to 0.30 μg/L by mass spectrometry detector, liying below the corresponding odor thresholds in all cases. Linearity, reproducibility, and recovery were considered satisfactory for most compounds, with typical R2 values of 0.989-0.999, relative standard deviation below 10 % for 37 compounds and between 10 and 20 % for 44 compounds, and recovery rates of approximately 100 % (85-109 %) for all but acetaldehyde. An analysis of 20 wine samples completed our validation of the method, showing that a single-sample preparation procedure combined with heart-cut multidimensional two-detector gas chromatography can determine wine volatile concentrations ranging from 350 mg/L of isoamyl alcohol to 3.8 ng/L of 3-isobutyl-2-methoxypyrazine.

Applying rosemary extract and caffeic acid to modify the composition of Monastrell wines

This work studies the effect of applying rosemary extract and caffeic acid on the polyphenolic and aromatic composition of Monastrell wines, as well as the influence of traditional winemaking or incorporating prefermentative maceration. For this purpose, three treatments were carried out in triplicate. In one of them, rosemary extract was applied on the clusters 10 days before harvest, caffeic acid was applied in the same way in another, and, finally, this acid was applied to grape before crushing. Each treatment was run by both traditional vinification and vinification with prefermentative maceration. After making wines, they were monitored for 12 months after fermentation. The application of rosemary extract, and that of caffeic acid but to a lesser extent, increased the color, the concentration of anthocyanins, and the percentage of polymerized anthocyanins, while prefermentation maceration gave rise to wines with a higher concentration of condensed tannins and polyphenols. Applying rosemary extract and caffeic acid in the vineyard also increased the concentration of esters and other compounds that favor wine aromatic quality, which was also enhanced by prefermentative maceration.

Changes in the Aromatic Compounds Content in the Muscat Wines as a Result of the Application of Ultrasound during Pre-Fermentative Maceration

This research focuses on the aromatic composition of Muscat of Alexandria wines after the application of ultrasound for 40 or 80 min during a 4 h pre-fermentative maceration process. Two methods of ultrasound application were compared in this study: probe ultrasound and bath ultrasound, for periods of 10–20 min per hour. Increases of more than 200% were obtained for some of the compounds from the skins, such as two of its terpenes, citronellol and nerol. On the other hand, increases in alcohol and ester values were registered with the application of ultrasound for 40 min. However, a significant decrease in these compounds was recorded when the ultrasound process was extended. In fact, when ultrasound was applied for 80 min, content values were even lower than those registered for the wine produced without the application of ultrasound. At the sensory level, the effect resulting from probe and bath ultrasound application for different times were compared, where most of the judges successfully discriminated the wines resulting from the application of ultrasound bath. According to data, the wines resulting from the application of ultrasound bath for 80 min presented the most significant differences, which affected the aromas of white fruit, tropical fruit, stone fruit, flowers and citrus.

Terroir Effect on the Phenolic Composition and Chromatic Characteristics of Mencía/Jaen Monovarietal Wines: Bierzo D.O. (Spain) and Dão D.O. (Portugal)

‘Mencía’/‘Jaen’ it’s an important red grape variety, exclusive of the Iberian Peninsula, used in wine production namely in Bierzo D.O. and Dão D.O., respectively. This work evaluates the effect of the two different “terroirs” on the phenolic composition and chromatic characteristics of ‘Mencía’/‘Jaen’ monovarietal wines produced at an industrial scale in the same vintage. Using Principal Component Analysis (PCA), Partial Least Squares-Discrimination Analysis (PLS-DA), and Orthogonal PLS-DA (OPLS-DA) it was found that peonidin-3-coumaroylglucoside, petunidin-3-glucoside, malvidin-3-coumaroylglucoside, peonidin-3-glucoside, malvidin-3-acetylglucoside, malvidin-3-glucoside, and ferulic acid were the phenolic compounds with the highest differences between the two regions. PLS regression allowed to correlate the differences in lightness (L*) and redness (a*) of wines from ‘Jaen’ and ‘Mencía’ to differences in colored anthocyanins, polymeric pigments, total pigments, total anthocyanins, cyanidin-3-acetylglucoside, delphinidin-3-acetylglucoside, delphinidin-3-glucoside, peonidin-3-coumaroylglucoside, petunidin-3-glucoside and malvidin-3-glucoside in wines, and the colorless ferulic, caffeic, and coutaric acids, and ethyl caffeate. The wines a* values were more affected by colored anthocyanins, ferulic acid, total anthocyanins, delphinidin-3-acetylglucoside, delphinidin-3-glucoside and petunidin-3-acetylglucoside, and catechin. The positive influence of ferulic acid in the a* values and ferulic, caffeic, coutaric acids, and ethyl caffeate on the L* values can be due to the co-pigmentation phenomena. The higher dryness and lower temperatures during the September nights in this vintage might explain the differences observed in the anthocyanin content and chromatic characteristics of the wines.

Advancement in analytical techniques for the extraction of grape and wine volatile compounds

The grape and wine aroma is one of the most determining factors of quality, therefore the study of their volatile composition is a very important topic in vitiviniculture. The range of concentrations in which many of these compounds are found is quite low, in concentrations of ng/L; due to this, a sample preparation stage is necessary before doing the chromatographic analysis of the volatile compounds. In this review, the main analytical techniques used for the extraction of volatile compounds in grapes and wines are studied. The techniques presented are liquid-liquid extraction (LLE), solid phase extraction (SPE), solid phase microextraction (SPME), stir bar sorptive extraction (SBSE), and thin film solid phase microextraction (TF-SPME). For each of these techniques, a description was made, and the different characteristics were numbered, as well as their main advantages and disadvantages. Furthermore, from the second technique, a comparison is made with the previous techniques, explaining the reasons why new techniques have emerged. Throughout the review it is possible to see the different techniques that have been emerging in the past years as an improvement of the classical techniques.

Effects of winemaking on ‘Marselan’ red wines: volatile compounds and sensory aspects

Winemaking processes and volatile compounds perform an important role in contributing to the quality of wines. ‘Marselan’ is a red grape variety grown in several countries such as France, Brazil and China. This variety has gained international interest in recent years. The volatile profile of Brazilian ‘Marselan’ red wines during various winemaking processes was studied. Four processes were applied: thermovinification, integrale vinification, classic winemaking and classic winemaking pretreated with ultrasound. The wines were characterized with conventional physicochemical analyses, volatile composition and sensory analysis. Sixty-three volatile compounds were identified and semi-quantified. The wines presented different sensory characteristics. The thermovinification and classic winemaking with ultrasound application methods showed a large presence of esters contributing to a fruity and overmaturation aroma in the volatile profile and sensory analysis. An increased presence of vegetal and sulfurous aromas was observed in the wines from the classic winemaking and integrale vinification processes. This effect was most likely attributed to the lower influence of esters which generated a greater perception of other compounds and conferred these aromas. The differences can be directly linked to the various extraction rates in the vinification processes, which result in different interactions between the compounds.

Evaluation of grape ripeness, carbonic maceration and pectolytic enzymes to improve the chemical and sensory quality of red sparkling wines

BACKGROUND

Red sparkling wines are and innovative product for the oenology market, and oenologists are looking for technologies to improve their winemaking. The present study aimed to use both carbonic maceration and pectolytic enzymes applied to premature grapes during the winemaking of red sparkling wines. Both could modify the release of polyphenols, as well as improve the foaming, aroma and sensory properties of the wines.

RESULTS

Red sparkling wines made with mature grapes showed the highest content of polyphenols, ethyl esters, alcohol acetates, total volatile acids and foam stability time. They were characterised by a high foam collar and foam area, full-body, astringency, persistence, and olfactory intensity, and were the best evaluated with respect to global perception in the sensory analysis. Treatment with pectolytic enzymes was not effective with unripe grapes. These wines showed a high content of total ethyl esters and the highest content of lactones, producing wines with high olfactory intensity and fruity aromas. Red sparkling wines made by carbonic maceration showed the lowest content of total polyphenols, anthocyanins and proanthocyanidins, as well as high contents of C6 alcohols and total ethyl esters, and were characterised by vegetal aroma notes. Both treatments produced red sparkling wines with good foam characteristics.

CONCLUSION

Winemaking of red sparkling wines with premature grapes and pectinolytic enzymes or carbonic maceration did not achieve an improvement with respect to their chemical and sensory qualities. The use of mature grapes and traditional winemaking is the best option for elaborating red quality sparkling wines. © 2020 Society of Chemical Industry.

An Approach of the Madeira Wine Chemistry

Madeira wine is a fortified Portuguese wine, which has a crucial impact on the Madeira Island economy. The particular properties of Madeira wine result from the unique and specific winemaking and ageing processes that promote the occurrence of chemical reactions among acids, sugars, alcohols, and polyphenols, which are important to the extraordinary quality of the wine. These chemical reactions contribute to the appearance of novel compounds and/or the transformation of others, consequently promoting changes in qualitative and quantitative volatile and non-volatile composition. The current review comprises an overview of Madeira wines related to volatile (e.g., terpenes, norisoprenoids, alcohols, esters, fatty acids) and non-volatile composition (e.g., polyphenols, organic acids, amino acids, biogenic amines, and metals). Moreover, types of aroma compounds, the contribution of volatile organic compounds (VOCs) to the overall Madeira wine aroma, the change of their content during the ageing process, as well as the establishment of the potential ageing markers will also be reviewed. The viability of several analytical methods (e.g., gas chromatography-mass spectrometry (GC-MS), two-dimensional gas chromatography and time-of-flight mass spectrometry (GC×GC-ToFMS)) combined with chemometrics tools (e.g., partial least squares regression (PLS-R), partial least squares discriminant analysis (PLS-DA) was investigated to establish potential ageing markers to guarantee the Madeira wine authenticity. Acetals, furanic compounds, and lactones are the chemical families most commonly related with the ageing process.

Acacia, cherry and oak wood chips used for a short aging period of rosé wines: effects on general phenolic parameters, volatile composition and sensory profile

BACKGROUND

There is a restricted knowledge about the potential impact of the use of different wood chip species on the rosé wine aging process. Thus, the aim of this work was to evaluate the general phenolic parameters, aroma composition and sensory profile of rosé wines during a short maturation (20 aging days) in contact with wood chips from oak, acacia and cherry. In addition, the different wood chips were added to a rosé wine without a previous clarification process (unfined wine) and to a rosé wine submitted to a clarification process (fined wine).

RESULTS

For the brief maturation time considered, the use of different wood chips induced a tendency for an increase of phenolic content, in particular for unfined rosé wine aged in contact with acacia chips. For volatile composition, the differentiation was clearer for aldehyde compounds group. Regarding sensorial overall appreciation the panel test preferred the unfined rosé wine aged in contact with acacia wood chips.

CONCLUSIONS

The results show that, in general, the use of different wood chip species (acacia, cherry and oak) for a brief maturation time of rosé wines could play an important role in rosé wine characteristics, in particular in their phenolic composition. © 2019 Society of Chemical Industry.