Oxygen consumption by oak chips in a model wine solution; Influence of the botanical origin, toast level and ellagitannin content

The Influence of Active Compounds of Chips Made from Different Wood Species on the Antioxidant, Oenological and Sensory Properties of Apple Wines

Wood chips contain numerous active compounds that can affect the wine's characteristics. They are commonly used in red grape wines, whisky, cherry and brandy, but in fruit wines, production is not typically utilised. The aim of this study was to compare the impact of an oak barrel ageing with the effect of the addition of chips made from various types of wood (oak, maple, cherry, apple) and with various degrees of toasting to the apple wines on their antioxidant, oenological and sensory properties. The oenological parameters, the polyphenols content, antioxidant activity and content of volatile odour-active compounds were assessed. It was shown that ageing in the presence of wood chips had a less noticeable effect on the oenological and sensory parameters of the wine than barrel ageing. Moreover, wood chips used did not significantly affect the acidity, alcohol and extract content of apple wines. Wines aged in the presence of oak chips (particularly lightly toasted) exhibited the greatest increase in polyphenols, while the polyphenol content of wines aged in the presence of other chips was not dependent on their toasting degree. The ageing of fruit wines with wood chips influences the volatile profile and the olfactory sensations, which can improve their quality.

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.

Development of a New Strategy for Studying the Oxygen Consumption Potential of Wine through the Grape Extract Evaluation

The development of a method to determine the aging potential of wine at the time of harvest, through the evaluation of its oxygen avidity, is a potential tool for the winemaking sector. To this end, it is necessary to formulate a potential wine with this grape prior to alcoholic fermentation. The main objective of this method was to optimize a formulation of the potential wine, based on the grape extracts (GEs), to subsequently evaluate its oxygen consumption kinetics, guaranteeing maximum differentiation between the different GEs. The optimization was carried out with a Taguchi orthogonal matrix design, which optimized the variables to be used in the GE reconstitution. The variables studied were pH, Fe2+, Cu2+, Mn2+, alcohol content and acetaldehyde. The evaluation of the characteristic parameters of the consumption kinetics of each of the GEs allowed us to know the different reconstitution conditions that most influence the differentiation of the oxygen consumption kinetics of very similar GEs. The reconstitution conditions chosen were pH 3.3; 1 mg/L Fe2+; 0.1 mg/L Cu2+; 1 mg/L Mn2+; 12% (v/v) alcoholic strength and 10 mg/L acetaldehyde, with pH, Fe2+ and Mn2+ being the significant conditions. The kinetics of reconstituted GE could be a tool for the classification and evaluation of grapes according to their aging potential or shelf life of the wine made.

The Role of Preservatives and Multifunctionals on the Oxidation of Cosmetic O/W Emulsions

Preservatives are typically used to protect cosmetic products from microbial spoilage. However, there is evidence that some preservatives can increase oxidation in O/W emulsions. This could have disadvantages for product quality, efficacy, and consumer health and well-being. Therefore, the impact of preservatives or multifunctionals on oxidation should be quantified. For this purpose, five O/W emulsions with different preservatives were prepared and stored. During storage, the oxygen concentration in the headspace of the samples was studied. The samples showed significant differences in their oxygen uptake and daily oxygen consumption rate. Thus, the preservatives used in this study had an influence on oxidation.

Identification and quantification of phenolic composition from different species of Jabuticaba (Plinia spp.) by HPLC-DAD-ESI/MSn

The aim of this study was to investigate phenolic compounds in peel, pulp and seeds of five different jabuticabas - Plinia trunciflora, "cabinho", P. cauliflora, cultivars "paulista" and "canaã-açu", P. jaboticaba, "sabará" and P. phitrantha, "branca-vinho". In addition to the commonly reported cyanidin-3-glucoside and delphinidin3-glucoside, it was also found the unreported cyanidin-3-coumaroylglucoside in the peels. Flavonols derived from quercetin and myricetin were also detected in jaboticaba peels, along with a wide variety of derivatives of ellagic acid and methyl ellagic acid. The latter derivatives occurred in acylated forms, which were not usually found in jabuticabas. The pulps and seeds of jabuticabas contained large amounts of ellagitannins vescalagin and castalagin, as well as gallic and ellagic acids. The jabuticabas showed small amounts of catechin and gallocatechin. P. jaboticaba showed the highest levels of anthocyanins and flavonols derived from myricetin, and P. phitrantha presented the highest concentration of ellagitannins and flavan-3-ols.

Bottle Aging and Storage of Wines: A Review

Wine is perhaps the most ancient and popular alcoholic beverage worldwide. Winemaking practices involve careful vineyard management alongside controlled alcoholic fermentation and potential aging of the wine in barrels. Afterwards, the wine is placed in bottles and stored or distributed in retail. Yet, it is considered that wine achieves its optimum properties after a certain storage time in the bottle. The main outcome of bottle storage is a decrease of astringency and bitterness, improvement of aroma and a lighter and more stable color. This is due to a series of complex chemical changes of its components revolving around the minimized and controlled passage of oxygen into the bottle. For this matter, antioxidants like sulfur oxide are added to avoid excessive oxidation and consequent degradation of the wine. In the same sense, bottles must be closed with appropriate stoppers and stored in adequate, stable conditions, as the wine may develop unappealing color, aromas and flavors otherwise. In this review, features of bottle aging, relevance of stoppers, involved chemical reactions and storage conditions affecting wine quality will be addressed.

Electrochemical Approaches for Rapid Characterization of Oxidizable Compounds in Different Oak Alternatives

Oak alternatives (OAs) such as chips, granulates or staves, are becoming increasingly used in the wine industry. Although they are mostly considered for their contribution to wine aroma, they are also a source of phenolic compounds to be released in the wine, in particular ellagitannins contributing to wine mouthfeel and antioxidant characteristics. In the present study, we explore the potential for a rapid analytical method based on linear sweep voltammetry (LSV) combined with disposable sensors to provide a rapid measure of the oxidizable compounds present in different OAs, as well as their characterization. Strong correlations were found between the tannin content of different OAs and the total current measures during LSV analysis, allowing a rapid quantification of the oxidizable compounds present, mostly ellagitannin. Application of derivatization to raw voltammograms allowed extraction of a number of features that can be used for classification purposes, in particular with respect to OAs types (chips or staves) and degree of toasting.

Oxygen and SO2 Consumption of Different Enological Tannins in Relationship to Their Chemical and Electrochemical Characteristics

The oxidative behavior of five commercial enological tannins of different sources (tea, grape marc, grape seed, untoasted oak, and toasted oak) was investigated in model wine solutions in the presence or absence of SO2. Solutions of the tannins were also analyzed for total phenolics, methyl cellulose precipitable tannins, high-performance liquid chromatography, and linear sweep voltammetry. Tea and oak-derived tannin solutions were characterized by the highest oxygen consumption rates, with oak-derived tannins exhibiting the highest oxygen consumption rates per milligram of phenolic material present. Linear sweep and derivative voltammetry parameters were well-correlated with oxygen consumption rates, whereas total phenolics or total tannins were not. All tannins were associated with consumption of SO2 upon reaction with oxygen, with the lowest rate of SO2 lost per milligram of O2 reacted being observed for oak tannins.

Behaviour of Low Molecular Weight Compounds, Iron and Copper of Wine Spirit Aged with Chestnut Staves under Different Levels of Micro-Oxygenation

Alternative technologies for a more sustainable wine spirits' ageing have been studied but a lack of knowledge on the effect of oxygenation level remains. This work examined the behaviour of low molecular weight compounds, iron and copper of a wine spirit aged in 50 L demijohns with chestnut wood staves combined with three levels of micro-oxygenation or nitrogen. Compounds and mineral elements were quantified by HPLC and FAAS, respectively, in samples collected at 8, 21, 60, 180, 270 and 365 days of ageing. Results showed that most of the compounds underwent significant changes in their content over time and behave differently depending on the wine spirit's oxygenation level: higher contents of gallic acid, syringic acid and vanillin were associated with lower micro-oxygenation level while higher contents of ellagic acid, syringaldehyde, coniferaldehyde and sinapaldehyde resulted from higher one; lowest contents of these compounds were found in the nitrogen modality. Weak correlation between copper and the studied compounds was evidenced whereas closer relationship between iron, vanillin, gallic, syringic and ellagic acids at end of ageing was observed. This study provides innovative information on the role of oxygen in wine spirit's ageing, and on chestnut wood effect on wine spirit's mineral composition.

Wine or Beer? Comparison, Changes and Improvement of Polyphenolic Compounds during Technological Phases

Wine and beer are nowadays the most popular alcoholic beverages, and the benefits of their moderate consumption have been extensively supported by the scientific community. The main source of wine and beer's antioxidant behavior are the phenolic substances. Phenolic compounds in wine and beer also influence final product quality, in terms of color, flavor, fragrance, stability, and clarity. Change in the quantity and quality of phenolic compounds in wine and beer depends on many parameters, beginning with the used raw material, its place of origin, environmental growing conditions, and on all the applied technological processes and the storage of the final product. This review represents current knowledge of phenolic compounds, comparing qualitative and quantitative profiles in wine and beer, changes of these compounds through all phases of wine and beer production are discussed, as well as the possibilities for increasing their content. Analytical methods and their importance for phenolic compound determination have also been pointed out. The observed data showed wine as the beverage with a more potent biological activity, due to a higher content of phenolic compounds. However, both of them contain, partly similar and different, phenolic compounds, and recommendations have to consider the drinking pattern, consumed quantity, and individual preferences. Furthermore, novel technologies have been developing rapidly in order to improve the polyphenolic content and antioxidant activity of these two beverages, particularly in the brewing industry.

Oxygen consumption rate of lees during sparkling wine (Cava) aging; influence of the aging time

Sparkling wines elaborated with a traditional method need to age in the bottle in contact with wine lees because yeast autolysis enriches the wines in colloids and improves their effervescence, foam and aromatic complexity. It is generally considered that lees protect the wine against oxidation because they consume small amounts of oxygen that can permeate the crown cap. However, to our knowledge there is no specific study on this subject using lees from real sparkling wine. Therefore, the oxygen consumption rate (OCR) of the lees of sparkling wines from the first to the ninth year of aging time was measured using a noninvasive fluorescence measurement method. The results indicate that lees really consume oxygen and that their OCR tended to decrease with the wine aging time. These data suggest that the lees' capacity to protect against oxidation decreases over time, which could affect the ability of sparkling wines to age properly.

A New Extract from Pomegranate (Punica granatum L.) By-Products as a Potential Oenological Tannin: Preliminary Characterization and Comparison with Existing Commercial Products

Oenotannins are nowadays widely used as co-adjuvant in the winemaking process. The increasing cultivation and consumption of pomegranate (Punica granatum L.) leads to high amounts of by-products, mainly peels. Aim of this study was to propose a dried tannin-rich extract from pomegranate by-products as a new oenotannin. A decoction was prepared from mesocarp of the Wonderful pomegranate variety only using hot water as extracting solvent. The dried decoction was physical-chemically characterized and compared to 7 existing commercial oenotannins from different botanical origin (grape seed, oak, gallnut), according to UV-Vis Spectroscopy, Colorimetric analysis (CIELab), gelatin index, reactivity to proteins, HPLC-DAD, DPPH, and Total Polyphenols content by both Folin-Ciocalteu and the International Organization of Vine and Wine (OIV) methods. Data showed the lowest antiradical (AR) and total polyphenolic content (TPC) for the pomegranate tannin but also the highest AR/TPC ratio suggesting a good radical scavenging potential of this new tannin. Pomegranate tannin showed high reactivity with proteins, a unique chromatographic profile, and a low color impact. The new pomegranate tannin showed an interesting potential for oenological applications in particular for reducing the use of sulfites during vinification and for the white wine stabilization.

Alternative Woods in Enology: Characterization of Tannin and Low Molecular Weight Phenol Compounds with Respect to Traditional Oak Woods. A Review

Wood is one of the most highly valued materials in enology since the chemical composition and sensorial properties of wine change significantly when in contact with it. The need for wood in cooperage and the concern of enologists in their search for new materials to endow their wines with a special personality has generated interest in the use of other Quercus genus materials different from the traditional ones (Q. petraea, Q. robur and Q. alba) and even other wood genera. Thereby, species from same genera such as Q. pyrenaica Willd., Q. faginea Lam., Q. humboldtti Bonpl., Q. oocarpa Liebm., Q. stellata Wangenh, Q. frainetto Ten., Q. lyrata Walt., Q. bicolor Willd. and other genera such as Castanea sativa Mill. (chestnut), Robinia pseudoacacia L. (false acacia), Prunus avium L. and P. cereaus L. (cherry), Fraxinus excelsior L. (European ash) and F. americana L. (American ash) have been studied with the aim of discovering whether they could be a new reservoir of wood for cooperage. This review aims to summarize the characterization of tannin and low molecular weight phenol compositions of these alternative woods for enology in their different cooperage stages and compare them to traditional oak woods, as both are essential to proposing their use in cooperage for aging wine.

Potential of Different Natural Antioxidant Substances to Inhibit the 1-Hydroxyethyl Radical in SO2-Free Wines

The potential of different natural antioxidants to inhibit the 1-hydroxyethyl radical formation in SO₂-free wines was analyzed by electron paramagnetic resonance (EPR). Chitosan, glutathione, inactive dry yeast, oak and grape seed extracts, and ascorbic acid were tested in white and red wines. The ability of these substances to prevent the formation of acetaldehyde after the Fenton reaction and the oxygen consumption capacity were measured. Ascorbic acid was the antioxidant substance that offered higher percentages of 1-hydroxyethyl radical inhibition at 30 min of reaction. However, wines with ascorbic acid showed higher concentrations of acetaldehyde after the Fenton reaction. Grape seed extract and chitosan provided higher percentages of radical inhibition in red wine than those in white wine, in contrast to the inactive dry yeast that only produced radical inhibition in white wine. Although oak extract did not produce changes in the 1-hydroxyethyl radical, wines with that extract had lower concentrations of acetaldehyde.

Relationship between polyphenolic content, antioxidant properties and oxygen consumption rate of different tannins in a model wine solution

The polyphenolic content and the antioxidant capacity of seven tannins with different botanical origin were measured with spectrophotometric methods (Folin-Ciocalteu, Total Polyphenols Index, DPPH, FRAP), HPLC (phloroglucinolysis), voltammetric analysis (Linear Sweep Voltammetry, LSV). The oxygen consumption rate (OCR) was measured in an oxygen saturated model wine solution, containing transition metals and metabisulphite, with a noninvasive luminescence-based technology. The results showed a high variability in polyphenolic concentration related to the botanical origin of tannins. The OCR determined over 21 days was described by quadratic equations, with coefficients varying with tannin botanical origin, dose and SO₂ concentration. The tannins ranked differently for antioxidant capacity, depending on the kind of test. The oxygen consumption parameters were positively correlated only with the LSV data measured with anodic current between 100 and 1200 mV (LSV_1200mV) and with the FRAP index.

Phenolic and volatile compounds in Quercus humboldtii Bonpl. wood: effect of toasting with respect to oaks traditionally used in cooperage

BACKGROUND

The most frequent renewal of barrels of different origins and species is a current trend, but this demand does not match the current availability of wood. An alternative could be the use of Quercus humboldtii wood. However, there is little information about its composition. Because of this, the aim was to study low-molecular-weight phenols (LMWP), ellagitannins and volatile compounds in untoasted and toasted Q. humboldtii oak, and compare these with the species traditionally used in cooperage: Q. petraea (French and Romanian) and Q. alba (American).

RESULTS

The LMWPs in Q. humboldtii were comparable to those in Q. petraea and Q. alba. Ellagitannin composition in Q. humboldtii was similar to that in Q. alba. The toasting process improved volatile composition, mainly in Q. humboldtii, presenting the highest concentration of several volatile compounds.

CONCLUSION

The results indicate that Q. humboldtii could be considered suitable for aging wine, although it is necessary to continue the study of this wood species to confirm its potential use in oenology. © 2018 Society of Chemical Industry.

Chemical characterization, antioxidant properties and oxygen consumption rate of 36 commercial oenological tannins in a model wine solution

The chemical composition (CC), antioxidant capacity (AC) and oxygen consumption rate (OCR) of 36 different commercial tannins were measured. The CC was analyzed by total polyphenol index, Bate-Smith, methyl-cellulose, Folin-Ciocalteu, OIV official method and phloroglucinolisis. The AC was measured by different methods (ABTS, CUPRAC, DPPH, FRAP, ORAC) using Trolox as standard. The OCR was measured using a non-invasive method based on luminescence. The results indicate that it is possible to obtain differentiation between procyanidins/prodelphinidins, profisetinidins/prorobinetidins, gallotannins and ellagitannins by PCA based on their CC data. It is also possible to separate condensed from hydrolysable tannins by PCA based on their AC data. The results show that ellagitannins are the fastest oxygen consumers of the various oenological tannins, followed in descending order by condensed tannins and finally gallotannins. The combination of CC, AC and OCR analyses enable to classify tannins according to their effectiveness in protecting wines against oxidation.

Astringency, bitterness and color changes in dry red wines before and during oak barrel aging: An updated phenolic perspective review

To understand effects of using oak barrels on the astringency, bitterness and color of dry red wines, phenolic reactions in wines before and after barrel aging are reviewed in this paper, which has been divided into three sections. The first section includes an introduction to chemical reactivities of grape-derived phenolic compounds, a summary of the phenolic reactions that occur in dry red wines before barrel aging, and a discussion of the effects of these reactions on wine astringency, bitterness and color. The second section introduces barrel types that determine the oak barrel constituents in wines (primarily oak aldehydes and ellagitannins) and presents reactions between the oak constituents and grape-derived phenolic compounds that may modulate wine astringency, bitterness and color. The final section illustrates the chemical differences between basic oxidation and over-oxidation in wines, discusses oxygen consumption kinetics in wines during barrel aging by comparing different oxygen consumption kinetics observed previously by others, and speculates on the possible preliminary phenolic reactions that occur in dry red wines during oak barrel aging that soften tannins and stabilize pigments via basic oxidation. Additionally, sulfur dioxide (SO₂) addition during barrel aging and suitability of adopting oak barrels for aging wines are briefly discussed.

An Approach to the Study of the Interactions between Ellagitannins and Oxygen during Oak Wood Aging

During the aging of red wine in oak wood barrels, or in alternative aging systems, interactions between the compounds released from wood, the compounds of the wine, and oxygen can take place. The main objective of the present work was to study oxygen-ellagitannin interactions by monitoring their levels in three model systems, all containing the same amounts of French oak chips and differing only in the oxygen content: total absence, only the oxygen released from the chips, and air-saturated (model systems F, OW, and OS, respectively). This study has highlighted the influence of oxygen in the ellagitannins' evolution and the relevance of the oxygen trapped into the oak chips, reporting for the first time the kinetics of oxygen release to the model wine. Furthermore, the indirect contribution of oxygen to the ellagitannins' disappearance by boosting autoxidative reactions has also been pointed out. Vescalagin seems to be the ellagitannin most affected by the initial oxygen levels.