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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...
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... flavonols, flava- nols and anthocyanins are classified as flavonoids. The basic structural difference between these classes is non-flavonoids contain only one phenol ring and flavonoids contain two phe- nol rings (ring A and ring B). Furthermore, the two phenol rings of flavonoids are connected via an oxygen-containing central pyran ring (ring C) (Fig. 2). The phenolic composi- tions and concentrations of grapes and wines are dependent on many factors, such as the climatic and geographic condi- tions of the vineyards in which they were grown in addition to the viticultural practices, variety and maturation degree of the grapes, and the maceration and fermentation methods Table ...
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... atoms on hydroxyl groups tend to transfer their electrons to the aro- matic ring and because of the mesomeric effect of hydroxyl groups. Thus, these carbons are negatively charged and react easily with electrophiles. Phenol rings with the strongest nucle- ophilic ability are those with a phloroglucinol structure, such as the A rings of flavonoids (Fig. 2b, Fig. 4a) ). The C6 and C8 on the A ring shown in Fig. 2b can function as nucleophilic sites; however, the C8 position is more prone to react with electrophiles due to its higher electron ...
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... the aro- matic ring and because of the mesomeric effect of hydroxyl groups. Thus, these carbons are negatively charged and react easily with electrophiles. Phenol rings with the strongest nucle- ophilic ability are those with a phloroglucinol structure, such as the A rings of flavonoids (Fig. 2b, Fig. 4a) ). The C6 and C8 on the A ring shown in Fig. 2b can function as nucleophilic sites; however, the C8 position is more prone to react with electrophiles due to its higher electron ...
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... flavonols, flavanols and anthocyanins are classified as flavonoids. The basic structural difference between these classes is non-flavonoids contain only one phenol ring and flavonoids contain two phenol rings (ring A and ring B). Furthermore, the two phenol rings of flavonoids are connected via an oxygen-containing central pyran ring (ring C) (Fig. 2). The phenolic compositions and concentrations of grapes and wines are dependent on many factors, such as the climatic and geographic conditions of the vineyards in which they were grown in addition to the viticultural practices, variety and maturation degree of the grapes, and the maceration and fermentation methods Table ...
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... atoms on hydroxyl groups tend to transfer their electrons to the aromatic ring and because of the mesomeric effect of hydroxyl groups. Thus, these carbons are negatively charged and react easily with electrophiles. Phenol rings with the strongest nucleophilic ability are those with a phloroglucinol structure, such as the A rings of flavonoids (Fig. 2b, Fig. 4a) ). The C6 and C8 on the A ring shown in Fig. 2b can function as nucleophilic sites; however, the C8 position is more prone to react with electrophiles due to its higher electron ...
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... to the aromatic ring and because of the mesomeric effect of hydroxyl groups. Thus, these carbons are negatively charged and react easily with electrophiles. Phenol rings with the strongest nucleophilic ability are those with a phloroglucinol structure, such as the A rings of flavonoids (Fig. 2b, Fig. 4a) ). The C6 and C8 on the A ring shown in Fig. 2b can function as nucleophilic sites; however, the C8 position is more prone to react with electrophiles due to its higher electron ...
Citations
... In addition, wine is widely consumed by the public for its pleasant organoleptic properties. According to the literature [3], the organoleptic characteristics of wine, such as smell, taste, and color, largely depend on the wine-making and aging techniques used. The aging of wine is a process widely used in oenology to provide added value to the wine [4]. ...
The time involved and the high economic cost of using oak barrels to age wines have led to a significant price difference compared to non-oak barrel aged wines and may lead to some fraudulent sales in the market. In this study, an untargeted metabolomic strategy was developed to detect the metabolite composition of oak barrel aged and non-oak barrel aged wines in both positive and negative ion modes by using UHPLC–HRMS combined with the recently developed chemometric method AntDAS. The results of partial least squares discrimination analysis (PLS-DA) showed that the samples were characterized into two categories. Finally, 51 compounds were identified in positive ion mode, while 26 compounds were identified in negative ion mode. The results indicate that combining UHPLC–HRMS with AntDAS can reveal the material basis of wines and has excellent potential to differentiate between oak barrel aged and non-oak barrel aged wines.
... ETs can represent up to 10% of the dry weight of the oak heartwood, being transferred to the wine during aging [17,55,56]. All the eight ETs identified in the traditional oak species, namely castalagin, vescalagin, granidin, and roburins (A, B, C, D, and E), were found in wines aged in oak barrels, the first two being generally the most abundant and representing nearly 50% of the total ETs [17,18,55,57,58]. Once in the wine, the ETs undergo continuous transformations, such as reactions with the components of the wine, as well as oxidation and hydrolysis reactions, or may be involved in tannin condensation [17,55,58]. ...
... All the eight ETs identified in the traditional oak species, namely castalagin, vescalagin, granidin, and roburins (A, B, C, D, and E), were found in wines aged in oak barrels, the first two being generally the most abundant and representing nearly 50% of the total ETs [17,18,55,57,58]. Once in the wine, the ETs undergo continuous transformations, such as reactions with the components of the wine, as well as oxidation and hydrolysis reactions, or may be involved in tannin condensation [17,55,58]. The products resulting from these reactions contribute to the feeling of bitterness and astringency and could affect the wine color [17,56,58]. ...
... Once in the wine, the ETs undergo continuous transformations, such as reactions with the components of the wine, as well as oxidation and hydrolysis reactions, or may be involved in tannin condensation [17,55,58]. The products resulting from these reactions contribute to the feeling of bitterness and astringency and could affect the wine color [17,56,58]. In particular, ethyl derivatives, such as β-1-O-ethylvescalagin, complexes colored red-orange with anthocyanins that alter the wine color, and also flavonoids, such as flavano-elagitanins (e.g., acutissimin A, acutissimin B, epiacutissimin A, and epiacutissimin B) [17,55,58]. ...
Ellagitannins (ETs) are a large group of bioactive compounds found in plant-source foods, such as pomegranates, berries, and nuts. The consumption of ETs has often been associated with positive effects on many pathologies, including cardiovascular diseases, neurodegenerative syndromes, and cancer. Although multiple biological activities (antioxidant, anti-inflammatory, chemopreventive) have been discussed for ETs, their limited bioavailability prevents reaching significant concentrations in systemic circulation. Instead, urolithins, ET gut microbiota-derived metabolites, are better absorbed and could be the bioactive molecules responsible for the antioxidant and anti-inflammatory activities or anti-tumor cell progression. In this review, we examined the dietary sources, metabolism, and bioavailability of ETs, and analyzed the last recent findings on ETs, ellagic acid, and urolithins, their intestinal and brain activities, the potential mechanisms of action, and the connection between the ET microbiota metabolism and the consequences detected on the gut–brain axis. The current in vitro, in vivo, and clinical studies indicate that ET-rich foods, individual gut microbiomes, or urolithin types could modulate signaling pathways and promote beneficial health effects. A better understanding of the role of these metabolites in disease pathogenesis may assist in the prevention or treatment of pathologies targeting the gut–brain axis.
... FLAVA are quite high reactive substances and, together with anthocyanins, would trigger the formation of different pigments and tannins in the wine-making process that modify the wine color and taste [51]. During aging, there are three main reactions in which anthocyanins participate, namely direct polymerization between anthocyanins and flavanols that produces anthocyanin-flavanol (A-T) and/or flavanol-anthocyanin (T-A) oligomers, indirect polymerization between anthocyanins and flavanols via acetaldehyde which produces purple flavanol-ethyl-anthocyanin adducts, and the formation of pyranoanthocyanins [52]. Thus, many researchers have focused their attention on most of the flavanols found in red wines, i.e., the monomeric (catechin and epicatechin), oligomeric (dimeric and trimeric B type procyanidins), and polymeric (tannins), and they evaluated their effects on copigmentation and the formation of new anthocyanin-derived red wine pigments. ...
Non-anthocyanin compounds (NAN) such as flavonol, flavanol, and phenolic acids should be considered in the characterization of minority red grapevine varieties because these compounds are involved in copigmentation reactions and are potent antioxidants. Sixteen NAN were extracted, identified, and quantified by High Performance Liquid Chromatography (HPLC) from grapes of 28 red genotypes of Vitis vinifera L. grown in Galicia (Northwest of Spain) in 2018 and 2019 vintages. The percentage of total NAN with respect to the total polyphenol content (TPC) values was calculated for each sample and established into three categories: high percentage NAN varieties (NANV), those varieties showing low percentages of NAN (ANV), and finally those varieties showing medium percentages of NAN (NANAV). ‘Xafardán’ and ‘Zamarrica’, classified as NANAV, had high values of TPC and showed good percentages of flavonol and flavanol compounds. Principal component analyses (PCA) were performed with flavonol, flavanol, and phenolic acid profiles. The flavonol and flavanol profiles allowed a good discrimination of samples by variety and year, respectively. The flavonol profile should therefore be considered as a potential varietal marker. The results could help in the selection of varieties to be disseminated and in the identification of the most appropriate agronomic and oenological techniques that should be performed on them.
... Panelists have also commented that yogurt with added MFDS powder had a bitter taste. The bitterness might be due to the presence of phenolics in the yogurt (Li and Duan 2018). According to the total phenolic content data from Fig. 2, yogurt with added MFDS powder was found to have the highest TPC out of all the samples. ...
As a widely consumed fermented milk product, yogurt undergoes constant development to increase its functional properties. Monascus purpureus -fermented durian seed, which has been proven to possess antioxidative properties, has the potential to improve yogurt properties. This study aimed to analyze the use of Monascus -fermented durian seed (MFDS) as a functional ingredient in yogurt and its effect on physicochemical properties, lactic acid bacteria (LAB) count, antioxidative properties, and consumer acceptability of set-type yogurt during refrigeration. Changes in physicochemical properties, including color, pH, titratable acidity, syneresis, LAB count, total phenolic content (TPC), and antioxidant activity were evaluated at 7-day intervals during 14 days of refrigerated storage (4 °C). Sensory evaluations were carried out for freshly made samples after 7 days of storage. The results showed that the addition of MFDS to yogurt gave significant effects on some of the parameters measured. Yogurt with added MFDS powder produced a more red color ( L = 88.55 ± 1.28, a * = 2.63 ± 0.17, b * = 11.45 ± 1.15, c = 11.75 ± 1.15, H = 77.00 ± 0.64), reached the highest TPC (2.21 ± 0.46 mg/GAE g), antioxidant activity (0.0125 ± 0.0032 mg GAE/g), and syneresis (5.24 ± 0.51%) throughout 14 days of storage. The addition of MFDS only gave a slight difference to pH and titratable acidity, while no significant difference was made for LAB count. For sensory evaluation, the addition of MFDS, particularly the ethanol extract, to yogurt was well-liked by panelists. Citrinin content in MFDS yogurt can be decreased under the limits set. Overall, the addition of MFDS has a high potential of improving yogurt properties, particularly its antioxidative properties.
Graphical Abstract
... As illustrated in Fig. 2A, unfermented strawberry juice (CON) had a lower total phenolic content associated with the possibility that it underwent a deeper oxidation reaction. On the other hand, the anthocyanin-flavanol adduct formed by the polymerization of flavanols and anthocyanins can also emit a yellow color (Li & Duan, 2019). But the process is reported to take longer, so it seems to be less likely to be triggered in lactic acid bacteria fermented juice. ...
The aim of this study was to investigate the impact of lactic acid bacteria fermentation on color expression and antioxidant activity of strawberry juice from the perspective of phenolic components. The results showed that both Lactobacillus plantarum and Lactobacillus acidophilus were able to grow in strawberry juice, promote the consumption of rutin, (+)-catechin and pelargonidin-3-O-glucoside, and increase the content of gallic acid, protocatechuic acid, caffeic acid and p-coumaric acid compared to group control. Lower pH environment in fermented juice was likely to enhance the color performance of anthocyanins and increase its parameters a* and b*, making the juice appear orange color. In addition, the scavenging capacity of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant capacity (FRAP) were improved and closely related to polyphenolic substances and strain’s metabolites in fermented juice.
... Panelists have also commented that yogurt with added MFDS powder had a bitter taste. The bitterness might be due to the presence of phenolics in the yogurt (Li & Duan, 2018). According to the total phenolic content data from Fig. 2, yogurt with added MFDS powder was found to have the highest TPC out of all the samples. ...
As a widely consumed fermented milk product, yogurt undergoes constant development to increase its functional properties. Monascus purpureus -fermented durian seed, which has been proven to possess antioxidative properties, has the potential to improve on yogurt properties. The purpose of this study was to analyze the use of Monascus -fermented durian seed (MFDS) as a functional ingredient on yogurt and its effect on physicochemical properties, lactic acid bacteria (LAB) count, antioxidative properties, and consumer acceptability of set-type yogurt during refrigeration. Changes in physicochemical properties, including color, pH, titratable acidity, and syneresis, LAB count, total phenolic content (TPC), and antioxidant activity were evaluated at 7-day intervals during 14 days of refrigerated storage (4⁰C). Sensory evaluation were carried out for freshly made samples and after 7 days of storage. Results showed that the addition of MFDS to yogurt gave significant effects to some of the parameters measured. Yogurt with added MFDS powder produced a more red color (L = 88.55 ± 1.28, a* = 2.63 ± 0.17, b* = 11.45 ± 1.15, c = 11.75 ± 1.15, H = 77.00 ± 0.64), reached the highest TPC (2.21 ± 0.46 mg/GAE g), antioxidant activity (0.0125 ± 0.0032 mg GAE/g), and syneresis (5.24 ± 0.51%) throughout 14 days of storage. Addition of MFDS only gave a slight difference to pH and titratable acidity, while no significant difference was made for LAB count. For sensory evaluation, addition of MFDS, particularly the ethanol extract, to yogurt was well liked by panelists. Overall, addition of MFDS has a high potential of improving properties of yogurt, particularly its antioxidative properties.
... Proanthocyanidins found in grape seeds and skins are of particular interest in viticulture and oenology [10] due to their contribution to the astringency and mouth-feel of wines, which has been attributed to their ability to form complexes with salivary proteins in the mouth [22,23] . The level of astringency has been shown to increase proanthocyanin DP as well as their degree of galloylation [24] . ...
Online comprehensive two-dimensional liquid chromatography (LC×LC) is the preferred method currently for the separation of highly complex mixtures of non-volatile compounds. With fully automated commercial instrumentation and software making the method appealing to both researchers and industry, the demand for systems with improved separation capabilities for highly complex mixtures such as those found in natural products or proteomics has increased. In this study we report an approach that enables variable second dimension analysis times based on the use of multiple heart-cutting valves and stop-flow operation to circumvent the requirement for very fast second dimension (²D) analyses in online LC×LC. As application, the HILIC×RP-LC analysis of condensed tannins (proanthocyanidins) in cocoa, grape seed and quebracho extracts is used to demonstrate the performance on the proposed methodology. The method offers increased flexibility compared to conventional online LC×LC separations in that longer ²D gradients can be used to accommodate more complex portions of the chromatogram, while shorter ²D gradients can be used in sections containing fewer peaks, while largely maintaining the benefits of comprehensive separation. We present an evaluation of the performance of the variable gradient time stop-flow HILIC×RP-LC method compared to a comparable, conventional online HILIC×RP-LC system in terms of practical peak capacities using established 2D-LC theory. The improved separation of especially low-level intermediate molecular weight proanthocyanidin oligomers by the former method demonstrates the benefits of the developed approach.
... Wine is an alcoholic beverage favored by consumers worldwide due to its unique flavor arising from chemical components such as water, ethanol, organic acids, phenolic compounds, proteins, polysaccharides, and numerous aroma compounds (Garrido-Banuelos et al., 2021;Li et al., 2021;Villamor & Ross, 2013). Phenolics and volatile compounds are dominant quality indicators that are directly responsible for wine color, mouthfeel, and aroma (Li & Duan, 2019;Panighel & Flamini, 2014;Trouillas et al., 2016). However, wine quality is not exclusively determined by these compounds and is influenced by interactions with other compounds in wine matrix. ...
Wine quality is closely related to various compounds including polysaccharides, a class of crucial macromolecules that can affect the chemical and physical properties of wine by influencing the colloidal state or interacting with other compounds via non-covalent bonds. Herein, the composition and structural characteristics of major polysaccharides identified in wine and the factors influencing their contents are briefly described. An improved understanding of the molecular mechanisms of wine polysaccharides and their practical application on wine quality is thoroughly discussed. The effect of polysaccharides on wine quality is significantly correlated with their structure and composition as well as wine matrix composition. Thus, to better understand the chemical complexity of polysaccharides, relevant analytical methods are systematically summarized and highlighted, which may ultimately lead to the development of novel winery guidelines.
... Barrel aging is a process in which wine or spirits are stored and aged in wooden barrels. Chemical reactions take place during the aging process in which wine or spirits are absorbed into the wood constituents, including volatile compounds that contribute to the smell property and non-volatile compounds that correlate with color and mouthfeel properties [6]. In recent years, aging maple syrup in bourbon barrels has become reporting on this novel product. ...
... In addition, a higher cultivation temperature of plants and higher activity of beneficial microbe/pathogen/insect feeding increase the total phenolic compounds, which also explain higher phenolics in dark maple syrups [31]. The higher phenolic content of BBL maple syrups could be associated with the aging process in the barrels, resulting in volatile and non-volatile phenolic compounds from the oak wood being absorbed [6] and contributing to their richer, more complex smell and flavor than traditional pure maple syrups. ...
This study aims to generate predictive models based on mid-infrared and Raman spectral fingerprints to characterize unique compositional traits of traditional and bourbon barrel (BBL)-aged maple syrups, allowing for fast product authentication and detection of potential ingredient tampering. Traditional (n = 23) and BBL-aged (n = 17) maple syrup samples were provided by a local maple syrup farm, purchased from local grocery stores in Columbus, Ohio, and an online vendor. A portable FT-IR spectrometer with a triple-reflection diamond ATR and a compact benchtop Raman system (1064 nm laser) were used for spectra collection. Samples were characterized by chromatography (HPLC and GC-MS), refractometry, and Folin–Ciocalteu methods. We found the incidence of adulteration in 15% (6 out of 40) of samples that exhibited unusual sugar and/or volatile profiles. The unique spectral patterns combined with soft independent modeling of class analogy (SIMCA) identified all adulterated samples, providing a non-destructive and fast authentication of BBL and regular maple syrups and discriminated potential maple syrup adulterants. Both systems, combined with partial least squares regression (PLSR), showed good predictions for the total ˚Brix and sucrose contents of all samples.
... Polyphenols determine the color, flavor, astringency, bitterness and aging behavior of red wine [11,12], which are all closely relevant to wine quality. Besides, antioxidant activity is the most fascinating property in relation to the health benefits of red wine consumption, and it has been studied by different in vitro and in vivo methods and related to the presence of polyphenols [13,14]; epidemiological studies have also demonstrated the correlation between long-term wine consumption and increased longevity in the population [15]. ...
Acetaldehyde is a critical reactant on modifying the phenolic profile during red wine aging, suggesting that the acetaldehyde-mediated condensation can be responsible for the variation of antioxidant activity during the aging of this beverage. The present study employs exogenous acetaldehyde at six levels of treatment (7.86 ± 0.10-259.02 ± 4.95 mg/L) before the bottle aging of Merlot wines to encourage phenolic modification. Acetaldehyde and antioxidant activity of wine were evaluated at 0, 15, 30, 45, 60 and 75 days of storage, while monomeric and polymeric phenolics were analyzed at 0, 30 and 75 days of storage. The loss of acetaldehyde was fitted to a first-order reaction model, the rate constant (k) demonstrated that different chemical reaction happened in wines containing a different initial acetaldehyde. The disappearance of monomeric phenolics and the formation of polymeric phenolics induced by acetaldehyde could be divided into two phases, the antioxidant activity of wine did not alter significantly in the first phase, although most monomeric phenolics vanished, but the second phase would dramatically reduce the antioxidant activity of wine. Furthermore, a higher level of acetaldehyde could shorten the reaction time of the first phase. These results indicate that careful vinification handling aiming at controlling the acetaldehyde allows one to maintain prolonged biological activity during wine aging.
