Wine aroma represents one of the main properties that determines the consumer acceptance of the wine. It is different for each wine variety and depends on a large number of various chemical ...compounds. The aim of this study was to prepare red wine concentrates with enriched aroma compounds and chemical composition. For that purpose, Cabernet Sauvignon red wine variety was concentrated by reverse osmosis (RO) and nanofiltration (NF) processes under different operating conditions. Different pressures (2.5, 3.5, 4.5 and 5.5 MPa) and temperature regimes (with and without cooling) were applied on Alfa Laval LabUnit M20 equipped with six composite polyamide RO98pHt M20 or NF M20 membranes. Higher pressure increased the retention of sugars, SO
, total and volatile acids and ethanol, but the temperature increment had opposite effect. Both membranes were permeable for water, ethanol, acetic acid, 4-ethylphenol and 4-ethylguaiacol and their concentration decreased after wine filtration. RO98pHt membranes retained higher concentrations of total aroma compounds than NF membranes, but both processes, reverse osmosis and nanofiltration, resulted in retentates with different aroma profiles comparing to the initial wine. The retention of individual compounds depended on several factors (chemical structure, stability, polarity, applied processing parameters, etc.).
Ecological viticulture represent an upward trend in many countries. Unlike conventional viticulture, it avoids the use of chemical fertilizers and other additives, minimizing the impact of chemicals ...on the environment and human health. The aim of this study was to investigate the influence of nanofiltration (NF) process on volatiles and chemical composition of conventional and ecological Cabernet Sauvignon red wine. The NF process was conducted on laboratory Alfa Laval LabUnit M20 (De Danske Sukkerfabrikker, Nakskov, Denmark) equipped with six NF M20 membranes in a plate module, at two temperature regimes, with and without cooling and four pressures (2.5, 3.5, 4.5 and 5.5 MPa). Different processing parameters significantly influenced the permeate flux which increased when higher pressure was applied. In initial wines and obtained retentates, volatile compounds, chemical composition and elements concentration were determined. The results showed that the higher pressure and retentate cooling was more favourable for total volatiles retention than lower pressure and higher temperature. Individual compound retention depended on its chemical properties, applied processing parameters and wine composition. Nanofiltration process resulted in lower concentrations of ethanol, acetic acid (>50%), 4-ethylphenol and 4-ethylguaiacol (>90%). Different composition of initial feed (conventional and ecological wine) had an important impact on retention of elements.
Stainless-steel tanks and wooden barrels are the most common wine ageing and storage vessels. Wooden barrels are often toasted to improve their chemical composition and influence on wine. The aim of ...this study was to investigate the changes in Merlot red wine aroma from the 2020 and 2021 vintages during 12-month storage (with sampling every 3 months) in a stainless-steel tank (SST), Excellence oak barrels with medium (EMT), medium plus (EMT+) and medium long (EMLT) toasting and a Premium oak barrel with medium toasting (PMT). The results showed that even slight differences in the time and temperature of medium toasting influenced the extraction of aroma compounds from wood to wine. The changes in individual aroma compounds depended on the vessel type, toasting level, initial wine composition and storage time. An increase in the total concentration of compounds with smoky, spicy and woody notes occurred in both wine vintages stored in wooden barrels, especially during longer storage. In samples from SST, floral, fruity and herbal aromas were more pronounced, according to the gas chromatography and sensory evaluators. Sensory evaluators rated the samples according to the 100-point test, and after 12 months of storage, 2020 and 2021 vintage Merlot stored in PMT obtained the highest points.
Wine aroma represents one of the most important quality parameters and it is influenced by various factors, such as climate conditions, viticulture and vinification techniques, storage conditions, ...etc. Wines produced from conventionally and ecologically grown grapes of the same variety have different chemical compositions and aroma profiles. The composition of wine can also be influenced by the additional treatment of wine, such as the concentration of wine by reverse osmosis (RO). The aim of this study was to investigate the influence of four different pressures (2.5, 3.5, 4.5 and 5.5 MPa) and two temperature regimes (with and without cooling) on the aroma profile and chemical composition of conventional and ecological Cabernet Sauvignon red wine during concentration by reverse osmosis. The results showed that different processing parameters influenced the permeate flux, the retentate temperature and the compounds retention. Higher working pressures (4.5 and 5.5 MPa) and the regime, with cooling, resulted in a higher retention of the total aroma compounds than the opposite processing parameters. The retention of individual compounds depended also on their chemical properties and their interactions with the membrane surface. The reverse osmosis membranes proved to be permeable for ethanol, acetic acid or undesirable 4-ethylphenol and 4-ethylguaiacol that made them applicable for their correction or removal.
This study investigated the chemical aromatic profiles of 60 volatile organic compounds (VOCs), including 21 terpenes, 6 norisoprenoids, 6 volatile phenols, 4 C-6 alcohols, and 23 esters, in ...Graševina wines originating from Slavonia and Podunavlje sub-regions (Croatia). Headspace solid-phase microextraction gas chromatography coupled with mass spectrometric detection (HS-SPME-GCMS) was used to assess 60 VOCs, and a novel HS-SPME-GCMS method for the determination of terpenes and norisoprenoids was developed and validated. Statistical analysis found no significant differences between VOCs present in Graševina wines and others wines (Chardonnay and Pinot gris); nonetheless, comparison of VOC fingerprints between different wines from the same producer showed that four terpenes (α-terpinene, γ-terpinene, 1,4-cineol, and 4-terpineol) were present in higher amounts in Graševina wines when compared to other wines. By exclusively examining VOCs within Graševina wines through the utilization of a heatmap and hierarchical clustering, a distinct visualization of samples and VOCs emerged, highlighting the vintage effect. Simultaneously, a partial least squares discriminant analysis model was developed with a confidence interval of 95%, demonstrating a noticeable distinction between samples originating from the western and eastern regions. Furthermore, by employing the heatmap using only VOCs from the terpene and norisoprenoidic groups, a clear separation of samples into two groups was observed based on geographical origin; namely, higher concentrations of norisoprenoids and terpenes were observed in the Slavonia sub-region. These results suggest that terpenes and norisoprenoids to a lower extent may be valuable aromatic markers for the regional typicality of Graševina wines.
Najzastupljenija vina u republici Hrvatskoj su vina sorte graševine. Od ukupne proizvodnje vina udio graševine iznosi čak 40,6 %. U uvjetima vinogradarske regije Slavonija i Hrvatsko Podunavlje od ...ove se sorte proizvode svi stilovi vina, od „mladog vina“, pjenušavog, dugo maceriranog, njegovanog na talogu kvasaca u hrastovim bačvama; od svih predikata do vrhunskih arhivskih primjeraka. Uz takvu raznolikost stilova vrlo je značajno definirati svako pojedino vino i na prikladan ga način predstaviti. Kako je iz više primjera vidljivo da često nedostaje vinskog vokabulara cilj rada je prikazati trenutne deskriptore pojedinih vina graševine Slavonije i Hrvatskog Podunavlja. S mrežnih stranica proizvođača vina prikupljeni su deskriptori boje, mirisa i okusa za 58 graševina koje su trenutno na tržištu. Kod vina redovne berbe najčešći deskriptori mirisa graševine vezani su uz zelenu jabuku, jabuku, citruse, cvjetno i voćno. Okus se najčešće opisuje kao svjež, lagan, ugodnih kiselina uz često isticanje blage gorčine koja se niti jednom ne spominje kod odležanih i maceriranih. Zrelija i kompleksnija vina zbog svoje složenosti često su opisana s više različitih deskriptora, a pojedini su vezani samo uz jedno vino.
Recent research has showed a breakthrough in investigating the effect of non-Saccharomyces yeast on wine quality and sensory properties. The aim of this study was to compare the influence of ...conventional yeast, Saccharomyces cerevisiae, vs. that of the non-Saccharomyces Torulaspora delbrueckii on the sensory profile of the white wine Graševina, and to establish if there are any differences in physical–chemical properties in regards to the applied yeast. Sample One was inoculated with both yeasts, while Sample Two was inoculated only with S. cerevisiae. The results indicated that a combination of T. delbrueckii and S. cerevisiae resulted in somewhat higher ethanol content in the finished wine. Sensory evaluation showed no significant discrepancies for any of the wines. Aspect and flavor were graded similarly, but the quality and intensity of the bouquet of Sample One was graded somewhat higher (14 and 6.6) than Sample Two (13.6 and 6.4). These findings open a very wide gate for future research in white wines.
Istraživanje je provedeno u vinogorju Kutjevo na položajima: Škomić, Vetovo, Hrnjevac, Vinkomir i Oljasi, na sorti Graševina tijekom 2020. godine. Položaji Vetovo, Hrnjevac i Vinkomir nalaze se na ...nadmorskim visinama iznad 300 metara dok su Škomić i Oljasi na oko 200 metara nadmorske visine na plodnijim tlima. Cilj istraživanja je bio prikazati utjecaj pojedinog položaja na dinamiku dozrijevanja grožđa i kakvoću mošta kroz osnovne parametre koji se danas najčešće koriste za određivanje tehnološke zrelosti grožđa. Uzorkovanje je obavljeno kroz prva dva tjedna rujna obzirom na klimatske prilike i ubrzano dozrijevanje grožđa. Pokus je postavljen po slučajnom bloknom rasporedu u tri repeticije. Fizikalno kemijske analize uzoraka obavljene su na uređaju WineScan u laboratoriju Kutjeva d.d.. Utvrđene su razlike u sadržaju šećera i ukupne kiselosti. Mošt Graševine s položaja Škomić imao je najniži sadržaj šećera tijekom cijelog perioda dozrijevanja i najveću ukupnu kiselost. Razlike u pH vrijednosti između položaja nisu utvrđene.
In this study, Cabernet Sauvignon red wine was subjected to reverse osmosis and nanofiltration processes at four different pressures (25, 35, 45, and 55 bar) and two temperature regimes (with and ...without cooling). The aim was to obtain concentrates with a higher content of phenolic compounds and antioxidant activity and to determine the influence of two membrane types (Alfa Laval RO98pHt M20 for reverse osmosis and NF M20 for nanofiltration) and different operating conditions on phenolics retention. Total polyphenol, flavonoid, monomeric anthocyanin contents, and antioxidant activity were determined spectrophotometrically. Flavan-3-ols and phenolic acids were analyzed on a high-performance liquid chromatography system and sample colour was measured by chromometer. The results showed that the increase in applied pressure and decrease in retentate temperature were favorable for higher phenolics retention. Retention of individual compounds depended on their chemical structure, membrane properties, membrane fouling, and operating conditions. Both types of membranes proved to be suitable for Cabernet Sauvignon red wine concentration. In all retentates, phenolic compounds content was higher than in the initial wine, but no visible color change (ΔE* < 1) was observed. The highest concentrations of phenolic compounds were detected in retentates obtained at 45 and 55 bar, especially with cooling.
The aim of this study was to assess the influence of the application of mycorrhizal fungal inoculum on “Cabernet Sauvignon” (Vitis vinifera L.) leaf gas exchange, yield parameters, as well as grape ...berry composition, especially regarding phenolic compounds. The experiment was conducted over two years under natural vineyard conditions of the Zagreb wine-growing area, the continental region of Croatia. “Cabernet Sauvignon” grapevines were grafted on SO4 rootstock, both being commonly used in all wine production areas in Croatia. Results obtained demonstrated that symbiotic grapevines, in general, expressed improved leaf gas exchange parameters and higher yield parameters, especially regarding the number of clusters per vine. It should be emphasized that mycorrhizal fungi affected higher total flavan-3-ols, total anthocyanins, and total polyphenols in berry skin in both experimental years. Despite variation in some yield parameters, generally, it is possible to obtain higher yields together with the improved phenolic composition of grapes.
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