Model Wine Research Articles

Physicochemical properties, antioxidant activities and comprehensive phenolic profiles of tea-macerated Chardonnay wine and model wine

A new type of flavored wine was produced by macerating either green tea or black tea into Chardonnay wine and model wine respectively, where the physicochemical properties (pH, titratable acidity, color) were modulated. Significant (p < 0.05) increases of total phenolic content and antioxidant activity (assessed by DPPH, FRAP and ABTS assays) were also observed in the tea macerated wines. A total of 160 phenolic and non-phenolic compounds were identified by HPLC-DAD-ESI-QTOF-MS/MS, where 55 phenolics were newly found in the tea macerated Chardonnay wine. The interaction between wine and tea phenolics led to additional 29 phenolic compounds and 4 non-phenolic compounds that were not found in either Chardonnay wine or tea. Catechin and epigallocatechin gallate were the most abundant phenolic compounds and contributed to the improved antioxidant activities. This study provided a promising prospect of tea as a novel additive in the production of flavored wine with enhanced functionalities.

PH dominates the temporal perception of astringency sub-qualities and saliva friction response – A study under iso-pH and iso-titratable acidity conditions in model wine

Astringency is a multidimensional perception comprising sensorily distinct sub-qualities. In wine production, attaining balanced astringency is critical to producing premium products. Although tannin has been viewed as the primary cause of wine astringency through colloidal interactions with salivary proteins and the modification of lubricating salivary film, how acids act in similar roles remains underexplored. This study aimed to address this gap by investigating the impact of acids (malic, lactic or tartaric acids) on the wine astringency profile under iso-pH and iso-titratable acidity (TA) conditions. Samples were sensorily evaluated with a progressive profiling method and tribologically tested to determine their impact on saliva lubrication. The results indicated that acids, independent of tannin, can elicit all astringency sub-qualities, and specifically that the pucker sub-quality is closely associated with low pH. pH had a more dominant impact on the temporal sensory scores than TA. At iso-TA, the score of all astringency sub-qualities was solely dependent on pH; at iso-pH, lowering TA increased the score of drying and roughness. The tribology results demonstrated that the rate of saliva friction increase was significantly correlated with pH but not TA. We propose that, during oral processing, pH dominates the process of saliva protein deformation, removal of lubricating pellicle, increased oral friction and astringency perception. However, high TA encourages saliva flow which neutralises oral pH and restores lubrication, counterbalancing the low pH’s contribution to astringency. Wine production processes could leverage this knowledge by implementing various acid-modification techniques to achieve the desired level of astringency quality of wines.

Volatile Compound Release from Oak Chips in Model Wine Media: Combined Influence of Toasting Degree, Size, Time of Contact, and Ethanol Content.

The effects of size, toasting degree, and time of contact on the release of volatile compounds from Quercus alba (L.) chips during a simulated fermentation and post-fermentative process were studied. The results obtained indicated that the large-size chips favored the release of furfural and furfuryl alcohol, while the small ones increased the concentration of cyclotene and maltol. The interaction between chip size and time of contact showed that the small-size chips are more sensitive to the increase of ethanol concentration for the extraction rate of some compounds (furfural, vanillin, maltol, cyclotene, whiskey lactones, and eugenol) compared to the large-size ones, increasing their concentrations at the end of maceration. The toasting degree of oak chips had a different influence on the volatile compounds studied. Cyclotene and guaiacol concentrations increased with the toasting intensity, whereas the extracted concentration of all compounds increased from light to medium-toasted chips, except for eugenol, and then decreased by further increasing the toasting level for 5-methylfurfural, whiskey lactones, eugenol, and only using high-level toasted chips for furfuryl alcohol, maltol, and vanillin. A possible protection effect of the chip size toward the possible degradation or volatilization losses of furfural for high toasting degrees was observed.

Role of p-Coumaric Acid and Micronutrients in Sulfur Dioxide Tolerance in Brettanomyces bruxellensis

Role of p-Coumaric Acid and Micronutrients in Sulfur Dioxide Tolerance in Brettanomyces bruxellensis

The role of Arabic gum on astringency by modulating the polyphenol fraction-protein reaction in model wine.

The potential contribution of Arabic gum to wine astringency was discussed in this study. Two universally used Arabic gum (concentration of 0.2-1.2g/L) were investigated in model wine based on the polyphenol fractions (phenolic acids, monomeric/oligomeric, and polymeric procyanidin) and protein interaction system. Both physicochemical analyses and sensory evaluation revealed that the modulation of Arabic gum on astringency was affected by the structural properties and concentration of Arabic gum and polyphenolic fractions. Arabic gum at 0.2g/L appeared as the optimal dose to reduce astringency compared to 0.6 and 1.2g/L. It inhibited astringency induced by polymeric procyanidin more than that of oligomeric procyanidins and phenolic acids mainly by forming soluble ternary complexes with polyphenols and proteins, and preferentially binding proteins/polyphenols to decrease polyphenol-protein reactions. Arabic gum also inhibited the self-aggregation of polyphenols, exhibiting more binding sites when its higher molecular weight and more/longer branches, leading to competition with polyphenols for bind proteins.

Electrochemical evaluation and voltammetric determination of some phenolic acids on the boron-doped diamond electrode

A simple, sensitive, and rapid method of determining phenolic acids, i.e. caffeic, ferulic, syringic, and vanillic using boron-doped diamond electrode (BDDE) by differential pulse voltammetry (DPV) was described. To the best of our knowledge, this is the first presentation of an electrochemical method to determine these compounds on BDDE. Under the conditions presented, the mentioned analytes undergo irreversible oxidation controlled by diffusion. The measurement conditions and composition of the supporting electrolyte were developed and optimized. Optimal measurement parameters ensure the usage of 0.02 mol L−1 ammonium citrate buffer pH 3.0 as a supporting electrolyte. The calibration graphs were linear with a correlation coefficient (r) >0.9959. The detection limits for the phenolic acids were within 0.01–0.03 mg L−1. Repeatability in all experiments, expressed by RSD%, was better than 5 %. The influence of interfering metal ions, such as Bi3+, Cd2+, Cu2+, Pb2+ and Tl+, was studied. The proposed method was successfully verified by measuring recoveries of phenolic acids in the model wine solution. The standard addition method was also applied in the determination of syringic acid in homemade and commercially available products: walnuts, walnut tincture, fresh and dried thyme. Effective application of the described analytical approach with the usage of BDDE not only enables the electrochemical detection of these four phenolic acids but also helps to reduce operational costs.

Characterization of 20 Oenological Tannins from Different Botanical Origins for Formulation of Blends with Redox Potential Tuning Ability in Model Wine Solution.

Twenty oenotannins from different botanical origins were studied in model wine solution (1 g/L, 12% ethanol, pH 3.5). An original device was created for measuring Oxidation-Reduction potential (ORp) of the solutions at 20 °C in strict anoxic condition by the electrochemical method of the platinum electrode zero-current potential. Reactivity against proteins and antioxidant properties were related to the chemical structure and, consequently, to the botanical origin of the oenotannins. The highest turbidity after BSA addition (ΔNTU > 1000) values were measured for the gallic hydrolysable tannins. The ORp versus standard hydrogen electrode ranged from 420 to 260 mV. The ellagitannins had the highest antioxidant power (AP%), followed by condensed tannins and gallotannins, highlighting a correlation with the phenolic profile. Based on these findings, two formulations were prepared as a blend of some of the tested oenotannins, with the ability to increase (MIX1) and decrease (MIX2) the ORp of the model wine.

New Insights on the Scalping Phenomenon of Volatile Sulphur Compounds on Micro-Agglomerated Wine Closures.

Flavour scalping in wine is a well-known phenomenon that is defined as the sorption of flavour compounds on wine closures. While the impact of closure type was the object of several studies, no research has addressed the impact of wine closure permeability on flavour scalping. For that purpose, the adsorption of volatile sulphur compounds (VSCs) on four micro-agglomerated wine cork closures was investigated by soaking them in model and Shiraz wines for 7 days. From a kinetic point of view, most of the VSCs were quickly scalped after 1 h of soaking, and this effect increased after 6 h until reaching a plateau. Most importantly, no significant impact of the closure on the kinetics and adsorption rates of the VSCs was found. As to the quantitative aspects, VSC sorption on closures accounted for 1% to 5% of the initial VSCs present in the wines only, meaning that the impact was negligible under oenological conditions.

Immobilization on biomimetic silica nanoparticles as a highly effective strategy for the stabilization of Issatchenkia orientalis β-glucosidase in wine conditions

β-Glucosidases (BGLs) are key enzymes for the hydrolysis of glycosidic aroma precursors of wines. However, BGLs produced by oenological yeasts are often inactive or unstable at typical wine pH values. In this work, different immobilization strategies on biomimetic NPs were tested to enhance the stability of Issatchenkia orientalis BGL and compared with traditional methods on agarose and Eupergit. Immobilization to biomimetic silica NPs by ionic interactions proved to be the most efficient method to achieve enzyme stabilization in model wine at pH 4.0. In particular, the subsequent glutaraldehyde crosslinking, achieved a high immobilization efficiency (71%) with an outstanding stabilization factor of 240-fold with respect to the soluble enzyme. This enzyme derivative preserved practically all the activity (98%) after15 days in model wine supplemented with Muscat glycosides, making possible its application for the release of aroma compounds relevant to the typicity of wine.

Aroma Perception of Limonene, Linalool and α-Terpineol Combinations in Pinot Gris Wine.

Aromatic white wines contain monoterpenes that can alter aroma qualities based on their concentration and enantiomeric ratios. Limonene has been identified as a monoterpene that is used to differentiate monovarietal white wines. The aim of this study was to evaluate the influence of limonene on aroma perception at different enantiomeric ratios. Its interaction with linalool and α-terpineol compounds was also investigated. Eighteen model wines were created with different ratios and/or concentrations of limonene and diverse concentrations of linalool and α-terpineol. Triangle tests, check-all-that-apply (CATA) and descriptive analysis were used to evaluate the aroma of the wines. Results show that different limonene ratios had no influence on wine aroma. Descriptive analysis showed that the addition of only limonene influenced citrus characteristics depending on the concentration. Linalool addition did not alter aroma quality when the limonene was at low concentrations, but it did change aroma perception at high limonene levels. α-Terpineol only altered the aroma of the wine at medium and high concentrations. At high concentrations, linalool and α-terpineol presented tropical aromas with some floral notes, irrespective of limonene levels. Depending on the desired aroma qualities of the wine, altering the monoterpene content resulted in very different aromatic wines.

Synthesis of a novel isotopically labelled standard for quantification of γ-nonalactone in New Zealand Pinot noir via SIDA-SPE-GC–MS

γ-Nonalactone is a linear aliphatic lactone ubiquitous in wine, associated with coconut, sweet, and stone fruit aroma descriptors. Little research has been conducted looking at the importance of this compound to New Zealand (NZ) wine aroma. 2H213C2-γ-Nonalactone, a novel isotopologue of γ-nonalactone, was synthesised in this work for use in a stable isotope dilution assay (SIDA) for quantification of γ-nonalactone in NZ Pinot noir wines for the first time. Synthesis was carried out using heptaldehyde as the starting material, and 13C atoms and 2H atoms were introduced via Wittig olefination and deuterogenation steps, respectively. The suitability of this compound as an internal standard was demonstrated by spiking model wine at normal and elevated conditions during sample preparation, with subsequent analysis via mass spectrometry showing stability of 2H213C2-γ-nonalactone. A model wine calibration, with concentrations of γ-nonalactone from 0 to 100 µg L−1, was shown to have excellent linearity (R2 > 0.99), reproducibility (0.72%), and repeatability (0.38%). Twelve NZ Pinot noir wines, representative of a range of NZ Pinot noir–producing regions, prices, and vintages, were analysed by solid-phase extraction–gas chromatography–mass spectrometry (SPE-GC–MS). The concentrations of γ-nonalactone ranged from 8.3 to 22.5 µg L−1, the latter of which was close to the odour detection threshold of this compound. These findings provide a basis for further research into γ-nonalactone and its impact on NZ Pinot noir aroma and provide a robust method for the quantification of this compound in Pinot noir.Graphical abstract

Investigation of molecular changes in wine during storage in refrigerated cabinets

Investigation of molecular changes in wine during storage in refrigerated cabinets

Yeast mannoproteins: Organoleptic modulating functions, mechanisms, and product development trends in winemaking

AbstractMannoproteins (MPs) originate from yeast cells and can play important roles in maintaining wine stability and modulating wine organoleptic properties. Due to their natural presence in wines, MP products are allowed to be used as enological additives in wine industry. To guarantee an appropriate application of these products during winemaking, it is necessary for both researchers and winemakers to understand the mechanisms of MPs as multifunctional organoleptic modulators. This review has introduced the current state of knowledge of the researches focus on the application of different MP products in red wines and also the interactions between MPs and wine sensory active components (polyphenols, aroma compounds) in model wine solutions. We have summarized the possible mechanisms of MPs that affect the color, astringency, and aroma of red wines and the relationship between the physicochemical characteristics and functionalities of MPs. Besides, development trends of MP products are also discussed. It seems that yeast biomass, especially those from non‐Saccharomyces yeasts show good potential in producing large quantities of MPs, an appropriate combination of yeast cultivation and preservation methods with extraction and purification techniques may obtain MPs of ideal production, purity, and functionality in an industrial scale, which should be put more efforts by both scientists and manufacturers in the future.

Interaction between Armenian clay-based ceramics and model wine during storage

Wine made or stored in clayware ceramic pots attracts the attention of consumers, but this practice is less studied than when classic stainless steel tanks or wood barrels are used. It is known that wine can be influenced by the container in which it is aged. To analyse the influence of ceramics on the chemical composition of wine, Armenian clay-based ceramic tablets were immersed in model wine and aged from 1 hour up to 16 months at 25 °C in darkness. The concentrations of 26 elements (namely: Al, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sr, Ti, V, W and Zn) in 19 samples were determined by ICP-AES analysis. Proton time domain NMR relaxometry was used to characterise the iron redox processes that occurred in the model wine in contact with a ceramic. A fast increase in the pH of the model wine in contact with the bare ceramic tablet (from 2.35 to 5) was recorded in 4 days. The coating of the ceramic tablets with beeswax showed a significant effect on the interaction between the model wine and the ceramic.

Chemical and Electrochemical Assessment of Wine Lees Extracts Tested as Novel Antioxidant Additives in Model Wine.

Yeast derivatives are used in winemaking for a variety of purposes, including the protection of wines from oxidation. In this work, by the application of an autoclave extraction method, different fractions were obtained from red wine lees and a lab-grown culture of the same yeast strain. Each extract was characterized for their protein, polysaccharide, glutathione, thiol, and polyphenol contents. The antioxidant activity was tested by adding each extract in a model wine enriched with catechin and saturated with oxygen. The presence of both wine lees and lab-grown yeast extracts delayed oxygen consumption when compared to the untreated control. This delay was confirmed by the development of a yellow color, which was lower in 5 out of 6 of the samples added with yeast/lees extracts. The electrochemical behavior of the samples also showed a greater resistance to oxidation, thus suggesting a protective role of the wine lees extracts against wine oxidative phenomena.

Microwave irradiation: Reduction of higher alcohols in wine and the effect mechanism by employing model wine

Reduction of higher alcohols contributed more to the aromatic characteristics of wine. In this paper, response surface methodology was used to optimize the parameters of microwave time, temperature, and power to obtain optimal microwave processing conditions for the maximum degradation rate of higher alcohols in model wine solution, and the maximum degradation rate of higher alcohol was 11.21% under optimized microwave conditions of 100 W, 50 °C and 3 min. The possible mechanism of microwave reducing on the higher alcohols was studied at optimized microwave conditions, the results showed that high concentrations of tartaric acid, glyoxylic acid, and ferrous ions could obviously decrease the content of higher alcohols; the content of higher alcohols in low concentrations ethanol and cupric ions was obviously lower than that in high concentration of ethanol and cupric ions; the appropriate (+)-catechin concentration had more obvious effect on higher alcohols content; the mannitol inhibited the degradation of higher alcohols and its subsequent reactions by scavenging free radicals in model wine solution. In summary, all these results could help understand the influence of improvement effect of microwave irradiation on the aromatic characteristics in wine by reducing the contents of higher alcohols.

Investigating wine astringency profiles by characterizing tannin fractions in Cabernet Sauvignon wines and model wines

Contribution of various phenols on wine astringency profiles was far from clear explanations. To effectively describe wine astringency profiles and determined the function of tannins/matrix (pH and ethanol), multiple chemical analyses combined RATA (Rate-all-that-apply) sensory method were applied in Cabernet Sauvignon and model wines. Results showed that polymeric flavanols determined the bulk of wine astringency intensity, oligomeric tannins enriched the smoothness and periodontium astringency, and monomeric phenol enhanced overall astringency intensity through synergistic effect. Astringency balance was effectively quantification, and its potential correlation relationship with epicatechin extension subunit (0.83) and fluorescence peak shift (0.75) cannot be ignored. The astringency profiles of condensed tannins with anthocyanins were enhanced. Low-pH (from 3.8 to 3.0) enhanced astringency by increasing the tannins affinity to proteins, while ethanol (from 10.0 % ∼ 15.0 %) decreased the hydrophobicity bond between tannins-protein interaction. This paper provided new insights to explain wine astringency profiles and a reference for astringency modification during winemaking.

Cover Image

The cover image is based on the Research Article Developing novel oenological tannins from 44 plants sources by assessing astringency and color in model wine by Chenyaqiong Cheng et al., https://doi.org/10.1002/jsfa.12247.image

Molecular Rearrangement of Four Typical Grape Free Terpenes in the Wine Environment.

In order to analyze the molecular rearrangement of terpenes in wine during aging, the changes in linalool, α-terpineol, nerol, and geraniol in model wine were investigated in the dark at low temperature for 90 days. Headspace-gas chromatograph-mass spectrometer/olfactometry was used for qualitative and relative quantitation of terpenes. Quantum mechanical calculation was used to analyze the Gibbs free energy. The results showed that nerol was converted into d-limonene, terpinolene, linalool, and α-terpineol. Geraniol was converted into β-ocimene, terpinolene, and linalool. Linalool was converted into terpinolene. The conversion rate of nerol to terpinolene was the highest with 5.94%. α-Terpineol was not converted spontaneously into other terpenes due to its lowest Gibbs free energy, indicating that the cyclization and isomerization could occur spontaneously through an exotherm reaction. However, the dehydroxylation of linalool, nerol, and geraniol required an energy source.

Replacement of SO2 by plant phenolic concentrates to control oxidations in winemaking

In conventional winemaking, sulfites have long been used to control oxidation and spoilage microorganisms. However, the current wine trends and growing consumer health concerns have increased the need to seek alternatives to this preservative. In this context, the present study investigated plant-phenolic concentrates and explored their potential to replace the useful properties of SO2 to control oxidations. The concentrates came from ten different plants and were provided by the company Biolethics Europe, from the Netherlands. Laccase activity control assays were performed using the syringaldazine chromogenic substratein must from botrytized grapes, and the oxygen consumption rate was measured using a non-invasive method based on luminescence in model wine solutions. Positive results were obtained in the two essays, which must be complemented with sensory analyzes and monitoring of the evolution of the wines.