Formation Of Pyranoanthocyanins Research Articles

Enhancement of pyranoanthocyanin formation in blueberry wine with non-Saccharomyces yeasts

The development of blueberry wine provides an alternative method for maintaining the nutritional value and extending the shelf life of blueberries. However, anthocyanin loss and off-flavor compound generation during fermentation impair blueberry wine color and quality. Hydroxycinnamate decarboxylase from yeast can catalyze the conversion of hydroxycinnamic acids to vinylphenols, which later may condense with anthocyanins to form more stable vinylphenolic pyranoanthocyanins. In this study, 10 non-Saccharomyces yeasts from Daqu that showed hydroxycinnamate decarboxylase activity were screened. Among the 10 strains, Wickerhamomyces anomalus Y5 showed the highest consumption (34.59%) of the total tested phenolic acids and almost no H2S production. Furthermore, Y5 seemed to produce four vinylphenol pyranoanthocyanins (cyanidin-3-O-galactoside/glucoside-4-vinylcatechol, cyanidin-3-O-galactoside/glucoside-4-vinylsyringol, malvidin-4-vinylguaiacol, and malvidin-4-vinylcatechol) during blueberry wine fermentation, which may improve the color stability of blueberry wine. These findings provide new insights for improving the quality of blueberry wine using non-Saccharomyces yeasts.

High yield production of cyanidin-derived pyranoanthocyanins using 4-vinylphenol and 4-vinylguaiacol as cofactors.

Pyranoanthocyanins are anthocyanin-derived pigments with vivid colors and enhanced stability, making them promising food colorants. We evaluated two 4-vinylphenols, decarboxylated p-coumaric (pCA) and ferulic acid (FA), as cofactors for pyranoanthocyanin formation. Cyanidin-3-glycosides from saponified black carrot were incubated with 4-vinylphenol or 4-vinylguaiacol in different anthocyanin-to-cofactor molar ratios (1:1-1:30) to form pyranoanthocyanins. Formation efficiency (45°C, ≤96h) was compared to their respective precursors at a 1:30 ratio. Composition changes were monitored using uHPLC-PDA-ESI-MS/MS. Pyranoanthocyanin yields with 4-vinylphenol (13.8-33.4%) were ∼12× higher than with pCA and yields with 4-vinylguaiacol (8.1-31.0%) were ∼6.5× higher than with FA. Molar ratios of 1:5 and 1:10 yielded significantly more pyranoanthocyanins. Pyranoanthocyanin formation with 4-vinylphenols followed first-order kinetics, whereas formation with hydroxycinnamic acids followed zero-order kinetics. Detection of intermediate compounds was consistent with a nucleophilic addition and aromatization formation mechanism. Overall, pyranoanthocyanin formation with 4-vinylphenols was more efficient than with hydroxycinnamic acids.

Enhancement of Pyranoanthocyanin Formation in Blueberry Wine with Non-Saccharomyces Yeasts

Enhancement of Pyranoanthocyanin Formation in Blueberry Wine with Non-Saccharomyces Yeasts

Influence of Fermentation Time on the Phenolic Compounds, Vitamin C, Color and Antioxidant Activity in the Winemaking Process of Blueberry (Vaccinium corymbosum) Wine Obtained by Maceration.

Flavonoid compounds, including anthocyanins and flavan-3-ol derivatives, total tannins, total vitamin C and resveratrol were analyzed by HPLC in blueberry fruits, their skin and pulp, as well as in wines produced from them. Two wines were elaborated, with different times of fermentation. The fruit analysis provided information on the distribution of bioactive compounds in the berries, showing that the skin had the highest concentrations of all compounds. The winemaking process needed a maceration stage to extract these compounds from skins to wine. This maceration process increased the concentration of all compounds and the antioxidant activity values measured by the DPPH assay, but long maceration times decreased the compounds and the antioxidant activity, due to the phenolic compounds that were involved in several reactions, such as polymerization, copigmentation, degradation, formation of pyranoanthocyanins and reactions between anthocyanins and tannins. The sensorial analysis of wines showed that partial fermentation wine had better characteristics than total fermentation wine, although both wines had a high acidity.

Influence of the Anthocyanin and Cofactor Structure on the Formation Efficiency of Naturally Derived Pyranoanthocyanins.

Pyranoanthocyanins are anthocyanin-derived pigments with higher stability to pH and storage. However, their slow formation and scarcity in nature hinder their industrial application. Pyranoanthocyanin formation can be accelerated by selecting anthocyanin substitutions, cofactor concentrations, and temperature. Limited information is available on the impacts of the chemical structure of the cofactor and anthocyanin; therefore, we evaluated their impacts on pyranoanthocyanin formation efficiency under conditions reported as favorable for the reaction. Different cofactors were evaluated including pyruvic acid, acetone, and hydroxycinnamic acids (p-coumaric, caffeic, ferulic, and sinapic acid) by incubating them with anthocyanins in a molar ratio of 1:30 (anthocyanin:cofactor), pH 3.1, and 45 °C. The impact of the anthocyanin aglycone was evaluated by incubating delphinidin, cyanidin, petunidin, or malvidin derivatives with the most efficient cofactor (caffeic acid) under identical conditions. Pigments were identified using UHPLC-PDA and tandem mass spectrometry, and pyranoanthocyanin formation was monitored for up to 72 h. Pyranoanthocyanin yields were the highest with caffeic acid (~17% at 72 h, p < 0.05). When comparing anthocyanins, malvidin-3-O-glycosides yielded twice as many pyranoanthocyanins after 24 h (~20%, p < 0.01) as cyanidin-3-O-glycosides. Petunidin- and delphinidin-3-O-glycosides yielded <2% pyranoanthocyanins. This study demonstrated the importance of anthocyanin and cofactor selection in pyranoanthocyanin production.

Improvement of Naturally Derived Food Colorant Performance with Efficient Pyranoanthocyanin Formation from Sambucus nigra Anthocyanins Using Caffeic Acid and Heat.

Consumers and regulations encourage the use of naturally derived food colorants. Anthocyanins (ACN), plant pigments, are unstable in foods. In aged red wines, ACN with a free hydroxyl group at C-5 condenses to form pyranoanthocyanins (PACN), which are more stable but form inefficiently. This study attempted to produce PACN efficiently using high cofactor concentration and heat. Elderberry anthocyanins were semi-purified and caffeic acid (CA) was dissolved in 15% ethanol and diluted with a buffer to achieve ACN:CA molar ratios of 1:50, 1:100, 1:150, and 1:200, then incubated at 65 °C for 5 days. The effect of temperature was tested using ACN samples incubated with or without CA at 25 °C, 50 °C, and 75 °C for 7 days. Compositional changes were monitored using uHPLC-PDA-MS/MS. Higher CA levels seemed to protect pigment integrity, with ACN:CA 1:150 ratio showing the highest tinctorial strength after 48 h. PACN content growth was fastest between 24 and 48 h for all ACN:CA ratios and after 120 h, all ACN had degraded or converted to PACN. PACN formed faster at higher temperatures, reaching ~90% PACN in 24 h and ~100% PACN in 48 h at 75 °C. These results suggest that PACN can form efficiently from elderberry ACN and CA if heated to produce more stable pigments.

Pyranoanthocyanin formation rates and yields as affected by cyanidin-3-substitutions and pyruvic or caffeic acids

Anthocyanin-derived pyranoanthocyanins (PACNs) offer potential as food colorants as they may exhibit higher stability than anthocyanins (ACNs). Our objective was to compare PACN formation rate and efficiency from different cyanidin-3-derivatives and cofactors, in order to facilitate PACN production. Four cyanidin-3-derivatives (cyanidin-3-glucoside, cyanidin-3-xylosylglucosylgalactoside, cyanidin-3-malonylglucoside and cyanidin-3-xylosyl(sinapoylglucosyl)galactoside) were incubated with pyruvic or caffeic acids (PA, CA) at 25 °C in the dark for two months. PACN formation was monitored by uHPLC-PDA-MS/MS over time. ACNs incubated with PA produced PACNs with yields increasing steadily over time, reaching 15% after 2 months. PACN formation with CA increased exponentially from the start, reaching 85% during storage. PACNs were efficiently produced from 3 of the 4 ACNs in the presence of CA, with minimal pigment loss. Copigmentation between CA and ACNs may facilitate PACN formation by keeping reactants in close proximity. Anthocyanin glycosylation and acylation affected PACN formation to a lower degree than cofactors.

Copigmentation with Chlorogenic and Ferulic Acid Affected Color and Anthocyanin Stability in Model Beverages Colored with Sambucus peruviana, Sambucus nigra, and Daucus carota during Storage.

The food industry is looking for alternatives to synthetic colorants. Anthocyanins (ACNs) are suitable replacements due to their color characteristics and potential health benefits. The application of sauco (Sambucus peruviana, SP) as a potential source of ACN-based colorants was evaluated and compared to elderberry (Sambucus nigra, SN) and an extract from purple carrots (PC). Color and pigment stability were evaluated using a model beverage system during eight weeks of storage. Copigmentation with chlorogenic acid (CGA) and ferulic acid (FA) were also evaluated. SP ACNs provided darker and more intense colors than those obtained with SN but less intense than those obtained with PC. Addition of CGA and FA resulted in significantly darker colors with higher chroma in beverages colored with SP and SN but not in beverages colored with PC. Copigmentation with FA reduced monomeric pigment half-lives for all ACN sources but increased the chroma half-lives of beverages colored with SP and SN, from 23 to 49 weeks, and from 23 to 55 weeks, respectively. Analyses using liquid chromatography coupled to photodiode array detection and mass spectrometry showed that interaction between non-acylated ACNs and FA resulted in the formation of pyranoanthocyanins. Overall, ACNs from non-acylated sources such as SP, in combination with FA, showed potential for commercial food applications.

Fate of Anthocyanins and Proanthocyanidins during the Alcoholic Fermentation of Thermovinified Red Musts by Different Saccharomyces cerevisiae Strains.

UV-visible spectrophotometry, size exclusion chromatography, and UHPLC-QqQ-MS were combined to evaluate the respective impacts of chemical changes and adsorption by yeasts on both proanthocyanidins (PA) and anthocyanins during the fermentation of a thermovinified red must by four yeast strains. Results evidenced a sharp decrease in anthocyanins (∼45%) and color intensity (∼50%), along with the formation of pyranoanthocyanins and flavanol-anthocyanin dimers related to yeast metabolism. However, the latter only accounted for 10% of anthocyanin losses. Comparison of spectrophotometry and phloroglucinolysis data underlined the involvement of PAs in chemical changes, related to yeast metabolites but also to direct reactions. Color losses during fermentation in this case study were mostly related to the formation of colorless compounds and to a decrease of copigmentation. Adsorption represented only a small proportion of pigment losses (∼5%) but a major part of those corresponding to total oligomeric/polymeric species, which were specifically involved. Only small differences could be evidenced between the four studied strains.

New insights into the chemical bases of wine color evolution and stability: the key role of acetaldehyde

The reactivity of malvidin-3-O-glucoside with acetaldehyde, pyruvic and p-coumaric acids, was separately studied in wine model solution in the presence and absence of catechin, by UV–Visible spectrophotometry, NMR and Mass spectrometry. These naturally occurring metabolites were selected on account of their role in determining the red wine color. The scientific bases underlying the wine color are far from being fully clarified. Nonetheless, understanding the factors that govern the wine color is a crucial prerequisite for winemakers to implement appropriate technological practices to produce naturally stable high-quality wines. Among the investigated wine metabolites, acetaldehyde turned out to be the most reactive towards malvidin-3-O-glucoside by forming, as major products, ethylene-linked polymeric pigments that affected chromatic properties of the wine-like model solutions. Pyruvic acid and p-coumaric acid did not react with malvidin-3-O-glucoside, but in combination with catechin, they both determined a significant hypsochromic effect. Unexpectedly, in our model solutions, the formation of pyranoanthocyanins was not observed.

The impact of Saccharomyces and non-Saccharomyces yeasts on wine colour: A laboratory study of vinylphenolic pyranoanthocyanin formation and anthocyanin cell wall adsorption

Wine fermentation is a complex process driven by yeasts, which influence the key properties of wine quality: aroma, flavour and colour. We investigated 95 different Saccharomyces and non-Saccharomyces strains for their impact on wine colour through the synthesis of the stable pigments, pyranoanthocyanins. All strains were screened for their hydroxycinnamate decarboxylase (HCDC) activity that varied from 0.0% to 91.1%. Eight strains that showed more than 40% HCDC activity were further studied for vinylphenolic pyranoanthocyanin formation. Fermentations were carried out in deep well microtiter plates using synthetic grape must containing Pinot Noir skin extract supplemented with p-coumaric acid. Two strains Pichia guilliermondii ZIM624 and Wickerhamomyces anomalus S138 synthesized vinylphenolic pyranoanthocyanins in the highest concentration in single culture fermentations, 40.2 and 38.5 mg L−1, respectively. The highest produced concentration of vinylphenolic pyranoanthocyanins in co-inoculation experiments was 16.4 mg L−1 compared to 29.8 mg L−1 in sequential fermentations. For the first time, S. paradoxus strains were assessed for pyranoanthocyanin formation. Selected strains were also tested as mono-cultures for adsorption of anthocyanins on yeast cell walls and all strains showed anthocyanin and pyranoanthocyanin adsorption to their cell wall with Metschnikowia reukafii ZIM2019 showing the highest adsorbing capability (9.1%).

Influence of Saccharomyces and non-Saccharomyces Yeasts in the Formation of Pyranoanthocyanins and Polymeric Pigments during Red Wine Making.

Yeast are able to modulate many sensory parameters of wines during red must fermentation. The effect on color and on the formation of derived pigments during fermentation has been studied thoroughly since the 90s. Yeast can increase grape anthocyanin’s color by acidification by hyperchromic effect (increase of flavylium molecules). Recent studies with non-Saccharomyces species, as Lachancea thermotolerans, described the intense effect of some strains on anthocyanin’s color, and subsequent, stability, by strongly reducing wine’s pH during fermentation. Moreover, selected yeast strains of Saccharomyces have been shown to release metabolites such as pyruvic acid or acetaldehyde that promote the formation of vitisin A and B pyranoanthocyanins during must fermentation. Schizosaccharomyces pombe, because of its specific metabolism, can produce higher concentrations of pyruvate, which enhances the formation of vitisin A-type derivatives. The hydroxycinnamate decarboxylase activity that some Saccharomyces strains express during fermentation also promotes the formation of vinylphenolic derivatives. Some non-Saccharomyces species, such as S. pombe or P. guilliermondii can also improve the production of these derivatives compared to selected strains of Saccharomyces cerevisiae. Lastly, some yeasts are also able to modulate the formations of polymeric pigments between grape anthocyanins and flavonoids, such as catechins and procyanidins.

Microwave-Assisted Extraction Applied to Merlot Grapes with Contrasting Maturity Levels: Effects on Phenolic Chemistry and Wine Color

Merlot grapes were harvested with three maturity levels (21.1, 23.1, and 25.1 Brix), and processed with or without the application of microwave-assisted extraction (MW). The detailed phenolic composition and color were followed during winemaking. The MW treatment did not affect the basic chemical composition of the wines. Upon crushing, MW caused a 211% improvement in anthocyanins in the wines of the first harvest and an 89% improvement in the wines of the third harvest. At bottling, MW favored the formation of pyranoanthocyanins and tannin-anthocyanin dimers. Tannin extraction was not affected by MW just after application of this process, but improvements of 30, 20, and 10% on MW-treated wines of the first, second, and third harvest, respectively, were recorded at pressing. The formation of polymeric pigments during aging generally increased along with harvest date and was only favored in MW-treated wines of the first and third harvest, with preferential formation of small polymeric pigments, in accordance with enhanced anthocyanin extraction in these wines. Initial improvements of wine color upon application of MW in the wines of the first, second, and third harvest were of 275, 300, and 175%, respectively. Although these differences subsided or disappeared for the wines of the second and third harvest during aging, the wines of the first harvest treated with MW retained 52% more color than Control wines at day 150 post-crushing. Results suggest the MW treatment was more efficient in extracting and retaining phenolics and color when applied to unripe fruit.

Influence of cyanidin glycosylation patterns on carboxypyranoanthocyanin formation

Anthocyanins can condense with compounds having enolizable groups to form pyranoanthocyanins. These pigments are less susceptible to degradation and color changes associated with nucleophilic addition common to anthocyanins. This study aimed to evaluate the impact of glycosylation patterns of anthocyanins on carboxypyranoanthocyanin formation. Nine cyanidin derivatives were isolated by semi-preparative HPLC. Pyruvic acid was added to induce pyranoanthocyanin formation. Composition (HPLC-MS/MS), spectra (absorbance 380–700 nm), and color (CIEL*c*h*) of solutions were monitored during 31 days storage at 25 °C. Cyanidin-3-glycosides with 1 → 6 disaccharides produced the highest pyranoanthocyanin yield (∼31%), followed by Cyanidin-3-monoglycosides (∼20%); 1 → 2 disaccharides produced the least proportions of pyranoanthocyanins (5–7%). Cyanidin-3-arabinoside converted to pyranoanthocyanins but degraded quickly (3% yield) under these conditions. No pyranoanthocyanins were formed from Cyanidin-3-sophoroside-5-glucoside. Glycosyl bonds were more critical than the size of the substitution alone, further supported by Cyanidin-3-(glucosyl)-(1 → 6)-(xylosyl-(1 → 2)-galactoside) yield (11%). Pyranoanthocyanins were hypsochromically shifted and had higher hue angles than their respective anthocyanins.

Are pyranoanthocyanins involved in sensory effect in red wines?

During the wine-making process and ageing, the formation of various groups of pyranoanthocyanins leads to enhance and to stabilize the red wine colour. Although their chemical properties and their formation kinetics have been well-described, data about their sensory impact are scarce. Micro-oxygenation can be used to favor the formation of pyranoanthocyanins and also to improve wine quality. For this study, both analytical and sensory aspects were used. Purification steps applied on an oxidized red wine lead to characterize three new original compounds. Sensory analysis was declined into two aspects. First the purification of an A-type vitisin-rich fraction will be used for evaluating the possible sensory impact of pyranoanthocyanins; then the correlation between the tasting of micro-oxygenated red wines and the concentrations of these wine samples in pyranoanthocyanins will determine if these pigments could enhance aroma characteristics.

Effect of Ferulic Acid on the Formation of Pyranoanthocyanins from Purple Corn (Zea mays L.) Cob in a Model System and Their Effects on Color

The stability enhancing effect of ferulic acid on anthocyanins from purple corn cob was investigated in a model system. The addition of ferulic acid provided color-enhancing and stabilizing effects on purple corn cob during storage and heating. These effects were observed through changes in spectrophotometric and CIE L*a*b* color space parameters. In test samples enhanced with ferulic acid, high-performance liquid chromatography–mass spectrometry detected and identified three new anthocyanin-derived pigments, cyanidin-3-glucoside-vinylguaiacol, pelargonidin-3-glucoside-vinylguaiacol, and peonidin-3-glucoside-vinylguaiacol, with respective m/z values of 595, 579, and 609.

Use of Schizosaccharomyces pombe and Torulaspora delbrueckii strains in mixed and sequential fermentations to improve red wine sensory quality

One of the main opportunities in the use of non-Saccharomyces yeasts is its great intraspecific variability in relation to the synthesis of secondary products of fermentation. Thus, mixed or sequential fermentation with non-Saccharomyces can increase the synthesis of certain metabolites that are important for colour stability, such as acetaldehyde and pyruvic acid (vitisin precursors) or vinylphenols (vinylphenolic pyranoanthocyanin precursors). Furthermore, the selection and use of non-Saccharomyces yeast strains with good yields in the production of certain volatile compounds (ethyl lactate, 2,3-butanediol, 2-phenylethyl acetate), with limited formation of higher alcohols, is a way to improve the aromatic profile of red wine. The main aim of this work was to evaluate the influence of sequential and mixed fermentations with Schizosaccharomyces pombe and Torulaspora delbrueckii strains on red wine's sensory quality. Anthocyanins and aromatic profiles, as well as glycerol and organic acid content, were analysed in the red wines obtained. Results show that, in general, mixed fermentations can promote an increment in polyols synthesis, while sequential fermentations can enhance the herbaceous aroma. Moreover, the use of T. delbrueckii in mixed fermentations allowed an increase to the fruity character of red wine. The use of S. pombe in sequential fermentations increased the stability of the colouring matter by favouring vitisins and vinylphenolic pyranoanthocyanin formation.

Optical properties of wine pigments: theoretical guidelines with new methodological perspectives

Wine pigmentation results from the complex chemistry of anthocyanins. Their flavylium cation form is stabilized either by chemical transformation occurring during wine aging (e.g., pyranoanthocyanin formation), or by the formation of non-covalent complexes with (phenolic) copigments.Molecular modeling (quantum mechanics and molecular dynamics) is more and more adapted to understand wine chemistry and pigmentation. The constant developments of theoretical methodologies might get non-specialists easily lost. This manuscript is a review of the theoretical studies dedicated to the field of wine pigments, showing conformational analysis, energetics of the various forms, pigment/copigment (non-)covalent association, and charge transfer excited states. QM/MM calculations are newly performed here, which improve solvent description. The conclusion is a comprehensive guideline for an accurate prediction of light absorption by wine pigments and all related supramolecular processes.

THE COMPLEX AGING BEHAVIOUR OF BERRY FRUIT JUICES: CONSEQUENCES FOR BIOACTIVES CONTENT AND QUALITY

It is well known that the processing of berry fruits into juices and nectars has a major impact on the concentration of secondary plant metabolites. The anthocyanins are more sensitive against aging than other polyphenols. The corresponding colour and quality change are limiting the shelf life and sensory acceptance by the consumer. The kinetics of anthocyanin degradation at 4 and 20°C are presented exemplarily for berry fruit juices. It is shown that the assumption of a first order reaction is only a rough approximation as many parallel and subsequent reactions can occur, leading to different aged pigments. Several mechanisms of anthocyanin-polyphenol reactions are known in fruit juices, among others the formation of pyranoanthocyanins and direct condensation to anthocyanin-tannin adducts. Furthermore, native anthocyanins can be bound to pectic polysaccharides during aging. The molecular fractionation by gel filtration revealed that the apparent molecular weights of these polymeric anthocyanin complexes can be higher than 10,000 Daltons. It can be expected that the resorption and bioavailability of anthocyanins is significantly influenced by these aging reactions. This leads to the question of realistic shelf life of the products.

Formation of pyranoanthocyanins by Schizosaccharomyces pombe during the fermentation of red must

Schizosaccharomyces pombe is a non-Saccharomyces yeast strain that can ferment grape musts with high sugar contents — but it also has other metabolic and physiological properties that render it of great interest to wine biotechnologists. This work compares the production of pyranoanthocyanins by S. pombe, Saccharomyces cerevisiae and Saccharomyces uvarum during fermentation. Total pyranoanthocyanins ranged from 11.9 to 19.4mg/l depending on the strain of S. pombe used. On average, S. pombe produced more pyruvic acid than did either Saccharomyces species; as a consequence it also formed more vitisin A-type pigments. S. pombe 938 produced the largest quantity of vitisin A (11.03±0.82mg/l). The formation of large amounts of pyranoanthocyanins intensifies the post-fermentation colour of wines somewhat, a phenomenon that helps them maintain their colour over ageing as the natural grape anthocyanins become degraded. Some of the S. pombe strains showed hydroxycinnamate decarboxylase activity, which favours the formation of vinylphenolic pyranoanthocyanins. Fermentation with S. pombe therefore provides an interesting way of increasing the overall pyranoanthocyanin content of red wines, and of stabilising their colour during ageing.