Headspace Solid-Phase Microextraction coupled to Gas-Chromatography with Mass Spectrometry detection (HS-SPME/GC-MS) has been widely used to analyze the composition of wine aroma. This technique was ...here applied to investigate the volatile profile of Trebbiano d’Abruzzo and Pecorino white wines produced in Abruzzo (Italy). Optimization of SPME conditions was conducted by Design of Experiments combined with Response Surface Methodology. We investigated the influence of the kind of sorbent, PDMS, CW/DVB, or PDMS/CAR/DVB, and the effect of the fiber exposure time, temperature, and salt concentration on the total area of the chromatogram and the extraction efficiency of ethyl decanoate and 3-methyl-1-butanol, representative of apolar and polar compounds, respectively. The PDMS/CAR/DVB sorbent allowed the extraction of about 70 compounds, whereas only a part of these substances could be extracted on the PDMS and CW/DVB fibers. Reliable response surfaces for the total area and peak areas of the selected volatiles collected on the PDMS and PDMS/CAR/DVB sorbents and, in the latter case, principal component analysis were evaluated to find the optimal conditions. The optimized extraction conditions were applied for a preliminary comparison of the volatile profile of the two wine varieties and in a successive varietal discrimination study based on data-fusion approaches.
BACKGROUNDIn the search of tools to deal with climate change-related effects along with the aim of avoiding the loss of aromatic typicity in wine, two native yeasts strains of Saccharomyces ...cerevisiae (CLI 271 and CLI 889) were evaluated to determine their influence on white Malvasia aromatica wines aroma composition and sensory characteristics. METHODSThe strains were tested versus a commercial yeast strain (LSA). The fermentations were performed on grape must of the Malvasia aromatica variety previously macerated. Wine quality was studied by analysis of oenological parameters together with volatile aroma components using gas chromatography coupled to flame ionization detector (GC-FID) to quantify major volatiles compounds and headspace-solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) to determine terpenoids and C13-norisoprenoids. Sensorial analysis was also realized by an experienced taster panel. RESULTSWines from locally-selected yeasts strains used had lower volatile acidity levels and higher concentration of aromatic compounds compared to the commercial strain ones. The yeast strain S. cerevisiae CLI 271 provided wines with a higher concentration of esters related to fruity attributes, especially isoamyl acetate. The tasting panel highlighted the strong floral character of wines from S. cerevisiae CLI 889 fermentation. CONCLUSIONSThe use of microorganisms well adapted to climatic conditions can be used to produce quality wines of the Malvasia aromatica variety.
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•Maceration and non-maceration treatments increased phenolic content in wines.•Wine bitterness and astringency were least affected by cold maceration treatment.•Prolonged maceration ...treatment obtained the highest colour intensity.•Late harvest vinification wine was the most favourable according to taste scores.
To investigate the effect of several vinification techniques aimed to enhance wine phenolic profile and sensory quality, maceration treatments of different duration and temperature (pre-fermentative cold one day maceration at 10 °C, seven days maceration at 16 °C, and prolonged post-fermentative 21 day maceration at 16 °C) and non-maceration treatments including tannin addition and late harvest grapes vinification were performed and compared to a standard white grape processing treatment. Produced wines were subjected to the analysis of phenols by high-performance liquid chromatography, colour intensity, and quantitative descriptive and hedonic sensory analysis. The increase in individual phenolic compound concentrations was mostly pronounced in maceration treatment wines, for both phenolic acids and flavan-3-ols, as well as for the sum of phenolic compound concentrations determined by high-performance liquid chromatography that tripled in relation to that determined in control treatment wine. Pre-fermentative cold maceration led to a moderate increase in phenolic compounds content without accentuating bitterness and astringency sensations. Wine phenolic composition and colour intensity were mostly affected by the prolonged post-fermentative 21 day maceration. Vinification of late harvest grapes produced a wine graded with the highest positive score for taste. The obtained distinct wine styles resulting from the application of the investigated practices may lead to a further diversification of white wine market.
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•A novel HRMS metabolomics approach was implemented on selected Greek white wines.•22 compounds were detected and quantified based on authentic standards.•79 tentative compounds were ...identified based on a smart suspect screening workflow.•A robust prediction and classification model was built for varietal discrimination.•Model top predictors were found to be isoquercitrin, shikimic and indolelactic acid.
LC-MS based metabolomics provide a new perspective in wine authentication enabling a thorough investigation of its chemical composition. In this study, 97 monovarietal white wines derived from four indigenous Greek grape varieties (Assyrtiko, Moschofilero, Malazouzia and Savatiano) and produced in two PDO and one PGI winemaking regions were analyzed with the use of ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS). A targeted metabolomics method was developed, validated and applied to the analyzed wine samples for the identification and quantification of 22 metabolites. Another 79 compounds were tentatively identified using a “smart” suspect screening workflow based on an in-house developed database. Then, the random forest algorithm was applied on the normalized peak areas of both target and suspect data for supervised statistical analysis. A robust classification model was built enabling the classification and prediction of the varietal origin of the wine samples in acceptable levels. Specific biomarkers, contributing significantly to the discrimination of wine variety, were recognized.
During aging, most bottled white wines lose their distinctive organoleptic characteristics according to their storage conditions (closure, temperature, time). However, the effect of these factors on ...organoleptic characteristics of Torrontes Riojano wines (TRw) has not been studied yet. This study aimed at evaluating the combined effect of closure type and storage temperature on the organoleptic properties development of TRw over a 18-month aging period, during which wine was bottled with natural (C) and synthetic (SyC) corks, and screwcaps (SC). Bottles were kept 18 months in thermostatized chambers (15 °C; 25 °C). At different aging times, consumed oxygen (CO), SO2, total phenols (TP), color, and sensory properties were evaluated. CO, TP, and browning index evolutions depended on the interaction between closure and temperature, whereas CIELAB parameters (lightness, chroma, hue) depended on closure-time and temperature-time interactions. At both storage temperatures, SC had a lower hue decrease and a lower chroma increase than C and SyC. The highest temperature prompted a more yellow and darker color of TRw. Thus, it allowed discrimination throughout the process. Considering the aging process, their aromatic intensity, fresh fruit, and yellow and green nuances decreased, while brown hue, color intensity, linalool, and oxidized character rose as their storage time was increased. At the end of their aging, TRw kept to 15 °C were not differenced by closure, and they were characterized by their fresh fruit, floral, and high aromatic intensity attributes. At 25 °C, SyC presented higher color intensity and herbaceous characters, while C and SC showed a more oxidized character. In conclusion, the interaction closure type-storage temperature is critical for organoleptic stability properties of bottled TRw during aging. Thus, screwcaps and low-temperature storage conditions can preserve the TRw varietal characteristics, increasing their shelf-life significantly.
•Torrontes Riojano wines aged in bottles modified their color and sensory properties.•Color changes were significant from 6 months of aging.•Wines sealed with natural and synthetic corks showed the most noticeable color changes.•During aging, wines were sensory discriminated by closure type and storage temperature.•Aging at 15 °C preserves the varietal characteristics of Torrontes Riojano wines.
SOsub.2 is a preservative often used in the food industry, particularly in the wine industry. However, regulatory authorities and consumers have been strongly suggesting its reduction or even its ...replacement. In order to understand the impact of SOsub.2 on the profiles of volatile organic compounds (VOCs) as well as amino acids (AAs), the aging of two white wines (one being a varietal and another being a blend) under identical conditions and in the presence of different doses of total SOsub.2 was studied. After alcoholic fermentation (t = 0), either no SOsub.2 was added (0 mg/L), or 30, 60, 90, or 120 mg/L of SOsub.2 was applied. The samples under study were kept on fine lees for 3 months (t = 3). After 3 months (t = 6) and 9 months (t = 12), the wines were bottled and analyzed. For t = 0 and t = 3, the samples were submitted to HS-SPME-GC/MS for VOC analysis and LC-DAD for AA analysis. From the principal component analysis of the detected VOCs, it was observed that the blended wine in comparison with the varietal wine, was less impacted by the applied SOsub.2 doses and aging time. From the AA profile, it was also observed in this study that maturation on fine lees resulted in an increase in the total concentration of AAs as would be expected.
The skins of two white wine grape pomace (WWGP) and three red wine grape pomace (RWGP) from US Pacific Northwest were analyzed for their dietary fiber (DF) and phenolic composition. DF was measured ...by gravimetric–enzymatic method with sugar profiling by HPLC–ELSD. Insoluble DF composed of Klason lignin (7.9–36.1% DM), neutral sugars (4.9–14.6% DM), and uronic acid (3.6–8.5% DM) weighed more than 95.5% of total DF in all five WGP varieties. WWGP was significantly lower in DF (17.3–28.0% DM) than those of RWGP (51.1–56.3%), but extremely higher in soluble sugar (55.8–77.5% DM vs. 1.3–1.7% DM) (
p
<
0.05). Soluble polyphenols were extracted by acidified 70% acetone and measured spectrophotometrically. Compared with WWGP, RWGP had higher values in total phenolic content (21.4–26.7
mg
GAE/g DM vs. 11.6–15.8
mg
GAE/g DM) and DPPH radical scavenging activity (32.2–40.2
mg
AAE/g DM vs. 20.5–25.6
mg
AAE/g DM) (
p
<
0.05). The total flavanol and proanthocyanidin contents were ranged from 31.0 to 61.2
mg
CE/g DM and 8.0 to 24.1
mg/g DM, respectively for the five WGP varieties. This study demonstrated that the skins of WGP can be ideal sources of DF rich in bioactive compounds.
► Dietary fiber and polyphenols of 5 wine grape pomace (WGP) skins were analyzed. ► Two different phenolic extraction methods were compared. ► Red WGP skins are high in phenolics and dietary fiber. ► Adding 0.1% HCl plus 1
h ultrasonic improved extraction efficacy of phenolics. ► Results provided baseline data for developing innovative utilizations of WGP.
White wine phenolics: current methods of analysis Clarke, Sarah; Bosman, Gurthwin; Toit, Wessel ...
Journal of the Science of Food and Agriculture/Journal of the science of food and agriculture,
15 January 2023, Letnik:
103, Številka:
1
Journal Article
A “turn-on” fluorescein-based probe for sulfite detection has been established employing SO32− promoted levulinyl cleavage and concurrent generation of fluorescein. The synthesized probe exhibits ...high SO32− selectivity over fourteen other anion ions, and the satisfactory detection limit was 0.80mg/L in aqueous media containing co-solvent CH3CN (1%, v/v). The probe is successfully applied for the detection of sulfite in white wine.
The oxygen transfer rate (OTR) of closures is a well-known parameter impacting the quality of Sauvignon blanc wines (SBw) within the first years of storage, but little research has been published on ...its long-term effects. The chemical changes in oxidation odor intensity in three SBw sealed with natural cork and other closures that had different known OTRs, ranging from <0.1 to 4.6 mg/year, were monitored over a 10 year period. During aging, free SO2 and 3-sulfanylhexanol loss, concomitant with increases in dissolved O2, OD420, and sotolon, were correlated with closure OTR levels. After 10 years of aging, sensory analysis was conducted, supported by additional chemical analysis of aroma impact markers, including methional, phenylacetaldehyde, 2-furanmethanthiol, 4-methyl-4-sulfanylpentan-2-one, ethyl-2-sulfanylacetate, and hydrogen sulfide, as well as total SO2 and dissolved CO2. These analyses revealed that selected SBw were protected from oxidation over a 10 year aging period, provided that the closure OTR did not exceed 0.3 mg/year.