Malvidin-3-glucoside Research Articles

Reactivity comparison of three malvidin-type anthocyanins forming derived pigments in model wine solutions

Malvidin-3-O-glucoside (MvG), malvidin-3-O-(6-O-acetyl)-glucoside (MvAG), and malvidin-3,5-O-diglucoside (MvDG) are three representative malvidin-type anthocyanins in red wine. In this study, the influence of structural differences on the formation efficiency of two types of derived pigments ((−)-epicatechin-ethyl-anthocyanins and pyranoanthocyanins) was investigated in model solutions using UHPLC-MS. The results showed that the yields of MvAG were higher than those of MvG to form both types of derived pigments, and the formation rate of pyranoanthocyanin was also relatively higher. In contrast, acetylation slowed the formation of (−)-epicatechin-ethyl-anthocyanins, indicating that the rate of covalent reactions may be linked to the affinity of (−)-epicatechin to copigment with anthocyanins. The condensation rate of MvDG with (−)-epicatechin, mediated by acetaldehyde, was much lower than that of the two monoglucosidic anthocyanins and also exhibited lower yields. In addition, pyranoanthocyanin was not generated from MvDG due to the absence of a free hydroxyl group at the C5 position.

The effects of copigments, sulfur dioxide and enzyme on the mass transfer process of malvidin-3-glucoside using a modelling approach in simulated red wine maceration scenarios

Maceration is fundamental to producing high quality red wine through the extraction of components from grape, including pigments of importance to wine colour. The effects of copigments and commonly used winemaking additives (maceration enzyme, SO2) on the extraction of malvidin-3-O-glucoside (M3G) were modelled under simulated maceration conditions. Copigments (gallic acid, rutin, caffeic acid) did not significantly facilitate the mass transfer process of M3G nor colour extraction, with caffeic acid having significantly lower values. Importantly, SO2 showed the most positive effects on both mass distribution constant and internal mass transfer coefficient of M3G, with temperature and ethanol having less of an impact. Significant interactions of the experimental factors were observed, however, and SO2, temperature, and ethanol were found to play predominant roles in the extraction phenomena. Comparatively, maceration enzyme or rutin (most impactful copigment) did not exhibit as much of an influence on the mass transfer process of M3G.

Effect of Different Processing Conditions on Bioactive Compounds of Selected Grape Varieties

Bioactive compounds in grapes vary in terms of cultivar and processing conditions. Raw juice and treated grape juices from locally grown Israel blue and locally available, imported, Red Globe and Michele Palieri varieties in Sri Lanka were used for the analysis. Grape juices were subjected to different processing conditions such as pasteurization and pectinase enzyme treatment. Total Monomeric Anthocyanin content (TAC), Total Phenolic Content (TPC), and antioxidant activity were analyzed. Compared to the imported grape varieties, the locally grown, pectinase enzyme-treated Israel blue grape juice with 2% pectinase enzyme concentration, 40 0C incubation temperature, and 2 hours incubation time, under dark condition had the significantly highest values (p < 0.05) for TAC at 177.03±4.15 mg/L of malvidin-3-O-glucoside (M3G), TPC at 527.07 ± 3.55 mg/L of Gallic acid equivalents and antioxidant activity in terms of DPPH radical scavenging assay with IC50 value at 7.05±0.35 mg/mL Gallic acid equivalents and ABTS radical scavenging assay with IC50 value at 0.31±0.01 mg/mL of Trolox equivalents. TAC, TPC, and antioxidant activity of three grape varieties showed the highest values in pectinase enzyme-treated grape juice which was followed by raw juice and the pasteurized juice respectively. This research has taken an approach to enhance the bioactivity of grape juices via pectinase enzyme treatment and evaluate the suitability of locally grown Israel blue grape variety in Sri Lanka to form as a functional beverage to meet nutritional and health requirements.

Identification of Stabilization of Malvid Anthocyanins and Antioxidant Stress Activation via the AMPK/SIRT1 Signaling Pathway.

Vitis amurensis Rupr. “Beibinghong” is abundant in anthocyanins, including malvidin (Mv), malvidin-3-glucoside (Mv3G), and malvidin-3,5-diglucoside (Mv35 G). Anthocyanins offer nutritional and pharmacological effects, but their stability is poor. Interaction of malvid anthocyanins with caffeic acid through ultrahigh pressure technology produces stable anthocyanin derivatives. This study aims to identify the structure of stable mallow-like anthocyanins and to determine the effect of these stable anthocyanins on human umbilical vein endothelial cells (HUVECs) with H2O2-induced oxidative damage and the signaling pathway involved. The products of malvid anthocyanins and caffeic acid bonding were identified and analyzed using ultra-high performance liquid chromatography-quadrupole-Orbitrap mass spectrometry (UPLC-Q-Orbitrap MS/MS). The bonding products were malvidin-3-O-guaiacol (Mv3C), malvidin-3-O-(6″-O-caffeoyl)-glucoside (Mv3CG), and malvidin-3-O-(6″-O-caffeoyl)-5-diglucoside (Mv3C5G). An oxidative stress injury model in HUVECs was established using H2O2 and treated with Mv, Mv3G, Mv35 G, Mv3C, Mv3CG, and Mv3C5G at different concentrations (10, 50, and 100 μmol/L). Results showed that the above compound concentrations can significantly increase cell proliferation rate and reduce intracellular reactive oxygen species at 100 μmol/L. The effects of the most active products Mv and Mv3C on the AMP-activated protein (AMPK)/silencing information regulator-1 (SIRT1) pathway were analyzed. Results showed that Mv and Mv3C significantly increased SOD activity in the cells and significantly upregulated the expression of SIRT1 mRNA, SIRT1, and p-AMPK protein. However, they did not significantly change the expression of AMPK protein. After the silent intervention of siRNA in SIRT1 gene expression, the upregulation of SIRT1 and p-AMPK protein by Mv and Mv3C was significantly inhibited. These results indicate that stabilization malvid anthocyanins exerts an antioxidant activity via the AMPK/SIRT1 signaling pathway.

The Effect of Pre-Harvest Application of Pectic Oligosaccharides and Abscisic Acid on Technological Ripening and Anthocyanin Profile of ‘Syrah’ Must and Grapes Grown in a Warm Climate

The progressive increase of environmental temperature as a consequence of climate change is a challengefor the wine industry. Elevated temperatures during grape ripening affect the development of grape skincolor by inhibiting the synthesis of pigments and promoting their degradation, which causes an imbalancein the chromatic quality of must and red wine. The application of pectic oligosaccharides (POs) and abscisicacid (ABA) triggers the phenylpropanoid pathway and increases the color index in grapes. Since the atharvestpigments and phenolic compounds are determinant for wine quality, this work addressed the preharvestapplication of POs and ABA as an in-field strategy for improving the quality of Syrah must andgrapes grown in a warm climate. The color development, physicochemical parameters, phenolic content,and pigments in berries and must were evaluated. Results showed POs and ABA improved berry colordevelopment and anthocyanin content during ripening. Musts from POs-treated berries exhibited thehighest phenols concentration and the most intense color, related to higher chroma values and anthocyanincontent, particularly delphinidin, petunidin, and malvidin 3-glucosides, while ABA improved must tonalityby reducing the hue angle. In summary, POs and ABA application at veráison, differentially modulatedthe technological ripening of Syrah grapes and can be an alternative to conventional agrochemicals topreserve the quality of musts elaborated from grapes grown in warm climates, by increasing the content ofphenolic compounds and enhancing berry skin color development through the differential accumulationof anthocyanins.

Malvidin-3-O-Glucoside from Blueberry Ameliorates Nonalcoholic Fatty Liver Disease by Regulating Transcription Factor EB-Mediated Lysosomal Function and Activating the Nrf2/ARE Signaling Pathway.

Nonalcoholic fatty liver disease (NAFLD) has become a universal health issue, whereas there is still a lack of widely accepted therapy until now. Clinical research studies have shown that blueberry could effectively regulate the lipid metabolism, thereby improving obesity-related metabolic syndromes; however, the specific active substances and mechanisms remain unclear. Herein, the effects of the major 10 kinds of anthocyanins from blueberry against NAFLD were investigated using an free fatty acid (FFA)-induced cell model. Among these anthocyanins, malvidin-3-O-glucoside (M3G) and malvidin-3-O-galactoside (M3Ga) could remarkably ameliorate FFA-induced lipid accumulation. Besides, M3G and M3Ga also inhibited oxidative stress via suppressing reactive oxygen species and superoxide anion overproduction, increasing glutathione levels, and enhancing activities of antioxidant enzymes. Further studies unveiled that the representative anthocyanin M3G-upregulated transcription factor EB (TFEB)-mediated lysosomal function possibly interacted with TFEB and activated the Nrf2/ARE (antioxidant responsive element) signaling pathway. Overall, this study enriched the knowledge about the health-promoting effects of blueberry anthocyanins against NAFLD and provided ideas for the development of functional foods of blueberry anthocyanins.

Understanding the molecular interactions between a yeast protein extract and phenolic compounds

Phenolic compounds are partially removed during fining, which may influence the organoleptic properties of beverages. Among phenolic compounds, tannins have been widely associated to the taste of beverages (namely astringency and bitterness). Furthermore, phenolic acids and anthocyanins may also influence bitterness and the latter are also responsible for beverages’ color. Thus, it is necessary to perform molecular studies to better understand the effect of fining agents in the overall phenolic composition of beverages and the resulting organoleptic changes. The molecular interactions between these three classes of phenolic compounds and a yeast protein extract (YPE), designed as a new fining agent, was studied. The binding affinities were assessed by fluorescence quenching at two temperatures (21 °C and 37 °C) and in two reaction media (water and wine model solution). The size of aggregates formed was characterized by Dynamic Light Scattering and the selectivity of protein interaction was analyzed by electrophoresis. Overall, pentagalloylglucoside (tannin) showed the highest binding affinity for YPE, followed by malvidin 3-glucoside (anthocyanin), p-coumaric acid (phenolic acid) and gallic acid (phenolic acid). The studied temperatures and solvents affected the interaction affinities as well as the aggregates’ size. Binding selectivity of proteins from YPE was not found. These results open new perspectives to control the fining process by using the YPE as a fining agent taking into account the further effect in the organoleptic properties of beverages.

Elucidation of the 3D structure of grape seed 7S globulin and its interaction with malvidin 3-glucoside: A molecular modeling approach

Plant proteins are biopolymers with interesting technological applications for the food industry due to their ability to interact with phenolic compounds such as anthocyanins. The 3D structure of the 7S globulin from grape seed was elucidated for the first time using a homology model. The constructed 3D model showed that grape seed 7S globulin is rich in α-helices and β-sheets stabilized by six disulfide bridges. The interaction with the major grape anthocyanin malvidin-3-glucoside was also assessed by Docking and Molecular Dynamic simulation. Theoretical results demonstrated that 7S globulin interacts with Mv3glc through hydrogen, alkyl and π-alkyl bonds and the flavylium cation is oriented towards a hydrophobic region of the protein, being protected from hydration. Results provide valuable insights for understanding the mechanisms involved in the molecular interaction of grape anthocyanins with grape seed proteins that could be relevant to use them as potential color protecting agents in food industry applications.

Integral use of Isabel grapes to elaborate new products with nutritional value and functional potential

Abstract The benefits of grape consumption are widely recognized and mostly due to phenolic compounds. These beneficial effects will depend on the bioaccessibility of these compounds on grape and its derivatives. This study elaborated two formulations of Isabel grape preparation: PAX (with agave and xylitol) and PS (with sucrose); and two formulations of Isabel grape flour: FAX (from the PAX process residues) and the FS (from the PS process residues). The products were analyzed regarding their nutritional and antioxidant properties; their phenolic compounds’ bioaccessibility was also verified through a simulated digestion model. The preparation and flour exhibited relevant sugars levels (10.83-49.71 g 100 g-1). Those produced with natural sweeteners had a reduction in sugar concentration of 51% and 29% for preparation and flour, respectively, compared to formulations with sucrose, with the high fiber content in the flour is being further highlighted (20.14-21.95 g 100 g-1). The catechin (2.37-28.11 mg 100 g-1) was the most bioaccessible compound (22% to 168%), which together with the caftaric acid (2.31-69.43 mg 100 g-1) and malvidin 3-glucoside (8.65-16.47 mg 100 g-1) represent the compounds observed in greater quantity. The preparations showed higher bioaccessibility regarding grapes and flours for most of the phenolic compounds. Furthermore, the products elaborated presented higher values of anthocyanins and antioxidant activity than the in natura grape, highlighting the beneficial effect of grape processing.

Carbohydrate Hydrolase-Inhibitory Activity of Juice-Based Phenolic Extracts in Correlation to Their Anthocyanin/Copigment Profile.

Red fruits and their juices are rich sources of polyphenols, especially anthocyanins. Some studies have shown that such polyphenols can inhibit enzymes of the carbohydrate metabolism, such as α-amylase and α-glucosidase, that indirectly regulate blood sugar levels. The presented study examined the in vitro inhibitory activity against α-amylase and α-glucosidase of various phenolic extracts prepared from direct juices, concentrates, and purees of nine different berries which differ in their anthocyanin and copigment profile. Generally, the extracts with the highest phenolic content—aronia (67.7 ± 3.2 g GAE/100 g; cyanidin 3-galactoside; chlorogenic acid), pomegranate (65.7 ± 7.9 g GAE/100 g; cyanidin 3,5-diglucoside; punicalin), and red grape (59.6 ± 2.5 g GAE/100 g; malvidin 3-glucoside; quercetin 3-glucuronide)—showed also one of the highest inhibitory activities against α-amylase (326.9 ± 75.8 μg/mL; 789.7 ± 220.9 μg/mL; 646.1 ± 81.8 μg/mL) and α-glucosidase (115.6 ± 32.5 μg/mL; 127.8 ± 20.1 μg/mL; 160.6 ± 68.4 μg/mL) and, partially, were even more potent inhibitors than acarbose (441 ± 30 μg/mL; 1439 ± 85 μg/mL). Additionally, the investigation of single anthocyanins and glycosylated flavonoids demonstrated a structure- and size-dependent inhibitory activity. In the future in vivo studies are envisaged.

Chemical description and organoleptic evaluation of Pinot noir wines from different parts of Italy: a three year investigation

Aim: this work gives a chemical description and sensory evaluation of several Pinot noir wines from different parts of Italy. For three subsequent years (2016-2018) the wine samples were submitted for in an Italian annual national Pinot noir competition aiming to define the best Pinot noir red wine from Italy. All of the wine samples were 3-years old (from vinification) at the moment they were analysed and evaluated; they were also registered for the competition the same year they were put on the market.Methods and results: all the wines were evaluated by a tasting panel composed of oenologists and wine experts, using the overall sensory quality as the descriptor. For the chemical screening, standard oenological chemical parameters (total acidity, colour, alcohol degree, total phenolic content, tannin indexes, etc.) and the content of the most abundant phenolic molecules by means of LC-MS analysis (triple quadrupole with internal standards) were determined. Pinot noir red wines produced from different parts of Italy showed a high variability for most standard wine chemical parameters considered, while the content of most single phenolic constituents was more retained and consistent with data from literature; except for t-resveratrol, which was significantly higher in our analyses, and delphinidin-3-glucoside, which was lower. Moreover, changes regarding the corresponding wines from the three vintages were noted. A correlation between the chemical parameters and the tasting panel results was also attempted. The results from a statistical analysis confirmed that alcoholic content, malvidin-3-glucoside and total anthocyanins had the highest positive impact on quality scores, while gallic acid, color tonality and total phenolic content had the highest negative.Conclusions: our results indicate that most wine producers have a conservative attitude with very slight differences found in the corresponding wines over the three years of investigation. The strong effects of agronomical, winemaking and ageing processes on chemical and sensorial features of Pinot noir red wines from Italy were also clearly shown. Compared to other monovarietal Pinot noir red wines from the same temperate area, single polyphenol content tended to be more retained than most standard chemical parameters.Significance and impact of the study: an overall quality assessment of a monovarietal wine, with its typicity as the main goal of a sensorial investigation, appears to be different from an objective quality assessment carried out by trained professional personnel using single standardised descriptors. Positive and negative correlations exist between sensorial judgement and chemical parameters, and the multiple linear regression model revealed relationships between the wine score and the set of the most important wine score description parameters.

Characterization of submicron emulsion processed by ultrasound homogenization to protect a bioactive extract from sea grape (Coccoloba uvifera L.).

In this study, the stability of a submicron emulsion to protect an extract obtained from sea grape fruit (Coccoloba uvifera L.) was evaluated. Extract characterization by MS-HPLC revealed the presence of 3 anthocyanins (cyanidin 3-glucoside, malvidin 3-glucoside, and delphinidin 3-glucoside), the content of total phenols was 263.86 ± 1.86 mg gallic acid equivalent/100 g, with an antioxidant capacity determined by ABTS and DPPH of 128.95 ± 1.00 and 26.18 ± 0.60 μg Trolox equivalents/mL, respectively. A submicron emulsion (0.424 μm) by Ultrasound with monomodal distribution, stable over time and low viscosity (1.94 mPa s) classified as a shear-thinning fluid was obtained. The thermogravimetric analysis (TGA) demonstrated the stability of the C. uvifera extract in the emulsion, which is thermostable (212 °C). These emulsions can be added into a beverage as a nutraceutical, dried for later use as pills or incorporated in foods.

Adsorption and biotransformation of anthocyanin glucosides and quercetin glycosides by Oenococcus oeni and Lactobacillus plantarum in model wine solution.

Anthocyanins and flavonols play a significant role in contributing to wine color and mouthfeel, and the interaction of malolactic fermentation with these compounds is not well known. Here we investigated the adsorption of these compounds by Oenococcus oeni and Lactobacillus plantarum. Delphinidin-3-glucoside (D3G) was adsorbed the most, followed by malvidin-3-glucoside (M3G) and peonidin-3-glucoside (P3G) for both the bacterial species, while flavonols were not adsorbed. An increase in β-glycosidase activity suggested that this enzyme breaks down the anthocyanin glucosides, providing sugars for growth. An average decline of approximately 65% in enzyme activity in the presence of substantial residual sugar was observed. The specific metabolic rates were found to be dependent on the class of anthocyanin and species / strain of the bacteria. Selective adsorption of anthocyanins and not the flavonol glycosides suggest that electrostatic interactions mediate the adsorption. Further, a breakdown of anthocyanins resulted in phloroglucinol aldehyde from the flavonoid A-ring and corresponding phenolic acids from the B-ring, i.e., gallic acid for D3G, syringic acid for M3G, and vanillic acid for P3G. The breakdown and adsorption of the anthocyanin glucosides can help explain the color loss and aroma changes, such as the appearance of syringic and vanillic acid, associated with malolactic fermentation. © 2019 Society of Chemical Industry.

Electrochemical Behavior and LC-MS Analysis of Anthocyanin’s in Vaccinium Arctostaphylos L. Extract: The Molecular Modelling of Potential Inhibition to COVID-19 and ROS Generation Receptors

Caucasian whortleberry (Vaccinium Arctostaphylos L.) is rich in anthocyanins, which possesses a wide range of biological and pharmaceutical activities. Electrochemical behavior of V. Arctostaphylos extract of dried fruit was performed by cyclic voltammetry and differential pulse voltammetry in aqueous solution. The results show that the level of delphinidin 3-O-glucoside (D3-OG) compound is higher than petunidin 3-O-glucoside (P3-OG) and malvidin 3-O-glucoside (M3-OG) level. This extract has a high solubility in water, and the potential-pH diagram indicates that the D3-OG capable oxidized to D3-OGOX with two electron/two proton process. D3-OG compound has a high antioxidant power because of the oxidation peak potential is low. Furthermore, total antioxidant capacity (1.475 C g−1) was determined by charges under of first oxidation peak. The antioxidant activity of three anthocyanins against Xanthine oxidase, Myeloperoxidase, NADPH oxidase, cytochrome P450 3A4 and 2B4 (ROS generation enzymes) has been performed through molecular docking studies. The results indicated that all the anthocyanins (D3-OG, P3-OG and M3-OG) bound exclusively to the binding site of ROS generation enzymes and have a remarkable role in suppressing the destructive effects of oxidative stress in the biological system of the human body. Also, D3-OG as a major anthocyanin of Vaccinium Arctostaphylos L. extract has an inhibition effect against the COVID-19 outbreak. Electrochemical approaches provided a simple, fast, low cost, green, and high sensitivity methods for investigation of electroactive compounds in plant extracts.

Malvidin 3-Glucoside Modulated Gut Microbial Dysbiosis and Global Metabolome Disrupted in a Murine Colitis Model Induced by Dextran Sulfate Sodium.

This study aims to elucidate the mechanisms of the anthocyanin malvidin 3-glucoside (MV) in alleviating gut dysbiosis using a murine colitis model induced by dextran sulfate sodium (DSS). The effect of MV on the structure and function of the colon microbiome and microbial metabolism is evaluated using 16S rRNA gene sequencing, global metabolomics, and a network algorithm based on the random-matrix theory. MV ingestion improved histopathological scores and increased IL10 expression in the colon mucosa of colitis mice. While DSS has a profound effect on the gut microbiome and significantly decreases both microbial richness and evenness, MV further reduces evenness but promotes microbial interactions and restores the Firmicutes/Bacteroidetes ratio repressed by DSS. Moreover, MV reduces the abundance of pathogenic bacteria, such as Ruminococcus gnavus, in colitis mice and has a strong modulatory effect on microbial co-occurrence patterns and gut metabolites. In addition, MV reverses several key inflammatory mediators, including sphingolipid metabolites, from elevated levels in DSS colitis mice. As a bioactive ingredient, MV exerts its effect on the gut microbiome in a mechanism that differs from the whole blueberry. MV ingestion ameliorates intestinal inflammation by modulating colon epithelium integrity, gut microbiome, and key inflammatory mediators.

Effect of Grape Seed and Skin Tannin Molecular Mass and Composition on the Rate of Reaction with Anthocyanin and Subsequent Formation of Polymeric Pigments in the Presence of Acetaldehyde.

Polymeric pigments formed via ethyl linkages between grape tannins and anthocyanins are important to the development of stable red wine color. To determine the effect of tannin structure on the stability and color properties of ethyl-linked polymeric pigments, tannin fractions with average polymerization between 4 and 43 units were prepared from grape skins and seeds and combined with malvidin-3-glucoside (M3G) in model wine containing acetaldehyde. As tannin molecular mass increased, the reaction rate with M3G increased. Compared with skin tannins of comparable molecular mass, seed tannins reacted more rapidly with M3G but were prone to precipitation. This resulted in a loss of polymeric pigments formed from seed tannins, which was greater as tannin molecular mass increased. Aggregation occurred following the reaction of seed tannin with M3G, concomitant with precipitation. The aggregation-precipitation phenomenon was not observed for skin tannin-derived pigments, indicating a greater stability in solution than those formed from seed tannins.

Mass Transfer of Anthocyanins during Extraction from Pre-Fermentative Grape Solids under Simulated Fermentation Conditions: Effect of Convective Conditions.

The colour of red wine is largely determined by the concentration of anthocyanins that are extracted from grape skins during fermentation. Because colour is a key parameter in determining the overall quality of the finished product, understanding the effect of processing variables on anthocyanin extraction is critical for producing a red wine with the desired sensorial characteristics. In this study, the effect of convective conditions (natural and forced) on the mass transfer properties of malvidin-3-glucoside (M3G) from pre-fermentative grape solids was explored at various liquid phase conditions representing stages of fermentation. A mathematical model that separates solid and liquid phase mass transfer parameters was applied to experimental extraction curves, and in all cases, provided a coefficient of determination exceeding 0.97. Calculated mass transfer coefficients indicated that under forced convective conditions, the extraction process was controlled by internal diffusion whereas under natural convection, both internal diffusion and liquid-phase mass transfer were relevant in determining the overall extraction rate. Predictive simulations of M3G extraction during active fermentation were accomplished by incorporating the current results with a previously developed fermentation model, providing insight into the effect of a dynamic liquid phase on anthocyanin extraction.

Evolution of Phenolic Compound Profiles and Antioxidant Activity of Syrah Red and Sparkling Moscatel Wines Stored in Bottles of Different Colors

The objective of this study was to evaluate the effects of storage time and bottle color on the phenolic compound profiles of Syrah red and sparkling Moscatel wines stored for 12 months in green, amber, and clear bottles. The profile of the phenolic compounds and their antioxidant activity in vitro were determined. Commercial wines were bottled in an automatic filling machine and closed with natural cork. After the bottling process, the wines were stored vertically on shelves which received natural light indirectly (±8 h/day), at temperatures which varied from 24 to 30 °C and relative humidity 40–65%. The wines were analyzed every three months over one year. Several phenolic compound families were quantified through reversed-phase high performance liquid chromatography (RP-HPLC) coupled to diode-array detection (DAD) and fluorescence detection (FD). The different bottle colors studied had not influenced the evolution of the sparkling Moscatel and Syrah red wines. The main variations obtained were related to storage time. The main changes were observed in the Syrah wine, where storage time was associated with an increase in hue (h*), decrease in catechin and epicatechin, and most notably, a decrease in the anthocyanin malvidin 3-glucoside. The sparkling Moscatel wine did not show important changes in most phenolic compounds; however, the catechin increased significantly during storage and this increase was similar in bottles of all colors. In general, the wines were stable in relation to the antioxidant activity in vitro.

Short communication: Purple corn (Zea mays L.) stover silage with abundant anthocyanins transferring anthocyanin composition to the milk and increasing antioxidant status of lactating dairy goats

The present study used 16 multiparous lactating Saanen dairy goats (body weight, 41.80 ± 2.92 kg; mean ± standard deviation) with healthy and symmetrical udders. Goats were divided into 2 blocks of 8 goats based on milk yield averaged from 75 d in milk in a randomized completed block design. The 2 study groups were the control (CSSS), in which goats were fed sticky corn stover silage, and the treatment (TPSS), in which goats were fed anthocyanin-rich purple corn (Zea mays L.) stover silage (PSS). The results indicated that the TPSS group led to an elevation in the content of milk lactose relative to the CSSS. The inclusion of anthocyanin-rich PSS had no effect on the level of 5 particular anthocyanins [i.e., cyanidin-3-glucoside, delphinidin, cyanidin, pelargonidin (Pel), as well as total anthocyanins in milk]. The pelargonidin-3-glucoside and malvidin were unable to be detected in both groups. However, the TPSS resulted in higher levels of peonidin (Peo) and malvidin-3-O-glucoside (M3G) compared with the control. Moreover, goats receiving TPSS exhibited a higher level of superoxide dismutase (SOD) in plasma and milk relative to the CSSS. Interestingly, some positive correlations were detected between the certain milk components [i.e., fat and total solids as well as fat and solids-not-fat (SNF); protein and SNF; and total solids and SNF]. In addition, the positive correlations were observed between individual anthocyanins (cyanidin-3-glucoside, delphinidin, Peo, M3G, cyanidin, and Pel) and total anthocyanins. Specifically, stronger positive correlations were noted between several antioxidant enzymes and anthocyanin composition in milk (total antioxidant capacity and Pel; SOD and Peo as well as SOD and M3G). Taken together, PSS with abundant anthocyanins can transfer anthocyanins to the milk and enhance the amount of antioxidants in lactating dairy goats.

Storage Temperature Impacts on Anthocyanins Degradation, Color Changes and Haze Development in Juice of "Merlot" and "Ruby" Grapes (Vitis vinifera).

This study evaluated the degradation kinetics of selected anthocyanins and the change in polymeric color, browning index, and haze development of grape juices from “Merlot” and “Ruby” grape cultivars stored at 5, 25, and 35°C for up to 360 days. Five major anthocyanins namely malvidin-3-O-glucoside (M3G), delphinidin-3-O-glucoside (D3G), petunidin-3-O-glucoside (Pt3G), peonidin-3-O-glucoside (Pn3G), and cyanidin-3-O-glucoside (C3G) were identified. Juice from “Merlot” had significantly higher (p < 0.05) content of all individual anthocyanins as compared to “Ruby.” During the long-term storage, total, and individual anthocyanins from both cultivars degraded following first-order reaction kinetics at the rate strongly dependent on temperature. At the end of the storage, noticeably higher loss of anthocyanins (95–99.9%) was observed at 25 and 35°C as compared to storage at 5°C [50–60% (“Merlot”); 74–81% (“Ruby”)]. Considerably lower rate of decay was observed at 5°C (k = 0.01–0.04) as compared to 25 (k = 0.04–0.14) and 35°C (k = 0.05–0.14) storage temperatures. The most temperature sensitive anthocyanin compounds were C3G (Ea = 66.5 kJ/mol) and D3G (Ea = 63.3 kJ/mol). At higher storage temperatures, significant (p < 0.05) and strong negative correlations were observed between anthocyanin concentrations and the levels of haze, polymeric and brown color development during storage. Storing grape juice, at lower temperature conditions could reduce the continuous loss of biologically active anthocyanins as well as the development of haze and brown color.