Individual Anthocyanin Content Research Articles

Artificial shading of teinturier grape Kolor clusters reveals light-responsive biomarkers: focus on flavonoid profiles and metabolism.

Kolor is a teinturier grape cultivar, that accumulates flavonoids in the skin and pulp. However, the concentrations and proportions of flavonoids in Kolor skin and pulp differ, suggesting tissue specificity in teinturier grapes. Light conditions significantly influence the evolution of flavonoids. Moreover, studies on the mechanisms governing flavonoid accumulation in light response sensitivity of teinturier grapes are limited. In the three consecutive years of study, the exposure of Kolor clusters was altered by bagging from pre-veraison to harvest. QqQ/MS and RT‒qPCR wereused to determine the individual anthocyanin contents and the relative gene expression. There was a significant decrease in the total anthocyanins and flavonols in the Kolor berries, with flavonols showing greater sensitivity to bagging. Bagging did not exert a consistent impact on the flavan-3-ols in Kolor berries. The sensitivities of anthocyanins in Kolor skin and pulp differed under light exclusion conditions. The concentration of trihydroxy-substituted anthocyanins in the skin decreased, while the proportion of dihydroxy-substituted anthocyanins in the pulp significantly increased, but the anthocyanin concentration in the pulp did not change significantly after bagging. The contents of malvidins and quercetins in the skin, and myricetins and quercetins in the pulp, were significantly reduced after bagging. The expression of flavonoid synthesis genes in Kolor skin and pulp was tissue-specific. After bagging, UFGT expression increased in the pulp and decreased in the skin. In addition, LDOX, FLS-1, CHI-1, CHI-2, F3H-1, F3H-2, and MYB4a exhibited sensitive light responses in both the skin and pulp. This study offers new insights into the regulation of flavonoids in Kolor grapes under light exclusion conditions.

The dynamic changes in pigment metabolites provide a new understanding of the colouration of Pyracantha fortuneana at maturity

The type, content and accumulation characteristics of pigments are the material basis for fruit colour and the evaluation basis of the fruit maturity and nutritional value of P. fortuneana. However, little information is available on the changes in carotenoids, anthocyanins, procyanidins and major flavones during the ripening process of P. fortuneana fruits. Thus, this study investigated the colour conversion characteristics, the main changes in the above four metabolites and the association landscape with those metabolites. The results showed that thirty-nine kinds of carotenoids and derivatives, eighteen anthocyanins, five procyanidins and five flavone compounds were identified in the fruits of P. fortuneana. The total content and contents of most individual carotenoids, anthocyanins, procyanidins and flavones reached the highest values at the TS2, TS4, TS1 and TS1 stages, respectively. Among the variations, the contents of β-carotene and lutein increased first and then decreased, cyanidin-3-galactoside and cyanidin-3-glucoside accumulated, the concentrations of procyanidin C1 and procyanidin B2 decreased, and the contents of rutin and quercetin-3-O-glucoside also decreased; these changers were responsible for the main changes in carotenoids, anthocyanidin, procyanidins and flavones, respectively. For the correlation analysis results, there might be two modes of action that together affected the colour conversion of P. fortuneana fruits during ripening, i.e., (E/Z)-phytoene communicated with the carotenoid metabolic pathway that might promote the accumulated ABA content, which might cause the increased anthocyanidin (primarily through cyanidin-3-(6-malonyl-beta-d-glucoside) (C3MG)) at the final stage; most of the decreased flavone and procyanidin metabolites produced by the flavonoid metabolic pathway were another important factor affecting the accumulation of C3MG.

Investigations into the stability of anthocyanins in model solutions and blackcurrant juices produced with various dejuicing technologies

Blackcurrant juices were produced with an oxygen-excluding spiral filter press and two conventional pressing systems exerting common oxygen exposure at pilot plant scale (200 kg) in technological duplicate in two subsequent years (n = 4). In contrast to findings on previously studied fruits, contents of total and individual anthocyanins were not significantly higher after spiral filter (1636–1872 mg/L) than after conventional pressing (1529–2083 mg/L). During storage for 52 weeks at 4, 20 and 37 °C, anthocyanin levels depended strongly on storage temperature, but not on the used pressing system (conventional vs. oxygen-reduced). Other juice quality parameters like ascorbic acid behaved likewise. Furthermore, a D-optimal design of experiments was used to study the influence and interactions of the factors oxygen, ascorbic acid, sugar and pH value on anthocyanin levels during a heat treatment in a model solution made with preparatively isolated blackcurrant anthocyanins. In agreement with our production trials at pilot plant scale, oxygen levels were only marginally important for the rate of anthocyanin degradation, but the influence of sugar content, ascorbic acid content and pH value was highly relevant as discussed in this report.

Impact of leaf removal as a source of stresses on grapevine yields, chemical characteristics, and anthocyanin content in the grapevine variety Babica

AbstractLeaf removal (LR) treatments improve the photosynthetic capacity of the remaining leaves and induce flavonoid synthesis as a stress response in the common grapevine (Vitis vinifera L.). However, excessive exposure of grape berries to UV‐B radiation as a result of cultural practices in the Mediterranean climate may have negative effects on berry composition. This 2‐year study determined the effects of defoliation on the autochthonous red grape variety ‘Babica’ in a Mediterranean climate (wine‐growing region Dalmatia, Croatia). Six leaves were removed before flowering (FLR) and at the end of véraison (the onset of grape ripening; VerLR) and were compared to the untreated control. Yield parameters, sugar content, grape must pH, total polyphenols (TP), total anthocyanin (TA) content, and individual anthocyanin compounds were measured in grape skin extracts and wines. However, the greater mean daily temperature during the vegetation period and lesser rainfall before harvest in 2018 increased yield per vine, average cluster weights, density, and total acidity, compared to 2017. Both defoliation treatments significantly reduced TP in grape extracts, but these differences were not observed in wine. Compared to the control (NLR), VerLR treatment significantly reduced TA in grape skin extracts and wine. Significantly lesser TP concentrations, in grape skin extracts and wine, as well as TA were noticed during the 2017 season. VerLR treatment reduced the concentration of nine individual anthocyanins compared to the control in grape skin extracts, while this effect was not observed in wine. Season year was a statistically significant source of variability of the individual anthocyanin contents in wine. Under specific environmental conditions LR can decrease polyphenols, especially anthocyanins, and negatively impact grape and wine quality.

Effect of Chlorella vulgaris on the Growth and Phytochemical Contents of “Red Russian” Kale (Brassica napus var. Pabularia)

Kale is a prominent leafy vegetable because of its high content of bioactive compounds and various health benefits. Microalgae have been suggested as a biostimulator that can replace chemical fertilizers by enhancing crop yield and supporting soil carbon sequestration. In this study, the effect of Chlorella vulgaris as a plant biostimulant on the growth and secondary metabolite contents of “Red Russian” kale (Brassica napus var. Pabularia) with green leaves and purple veins has been demonstrated. Three Chlorella treatments were used: CS, C. vulgaris suspension; CB, C. vulgaris biomass; and CFS, filtered C. vulgaris-free supernatant. The plant growth rates, phytochemical contents, and individual glucosinolate and anthocyanin contents were determined. There was no significant difference under the CS and CB treatments, while CFS negatively influenced on kale growth with 37% reduction of dried weight. In contrast, metabolite production differed according to Chlorella treatments. Total contents of chlorophyll and carotenoid were increased by 1.57 and 1.41 folds by CS treatment, whereas total contents of phenol and flavonoids were enhanced by 1.30 and 1.22 folds by CFS treatment. Totally, seven glucosinolates and four anthocyanins were characterized and quantified individually. Notably, CFS treatment increased gluconasturtiin and all anthocyanins the most, 10.28-fold and 5.90-fold, respectively.

Increase in thermal stability of strawberry anthocyanins with amino acid copigmentation

Copigmentation effects of aspartic acid, proline and valine on individual anthocyanins in strawberry juice (SJ) were investigated during heating at 90, 105 and 150 °C. Aspartic acid increased (4.5–45.6%) total anthocyanin stability at all temperatures, while proline and valine had no effect at 90 °C but reduced (2.2–19.4%) stability at 150 °C. At 90 °C, aspartic acid and valine caused the highest Amax. Evaluating changes in individual anthocyanin contents, Amax, colour density and polymeric colour of SJs together revealed that aspartic acid had copigmentation effects on pelargonidin-3-glucoside and pelargonidin-3-rutinoside, whereas valine on pelargonidin-3-glucoside and cyanidin-3-glucoside. At 105 °C, all amino acids increased (7.9–33.1%) stabilities of pelargonidin-3-glucoside, pelargonidin-3-rutinoside, Amax and colour density all of which together pointed out the copigmentation. At 150 °C, interactions between “aspartic acid-pelargonidin-3-glucoside,” “proline-pelargonidin-3-rutinoside” and “valine-pelargonidin-3-rutinoside” resulted in high colour density. Thus, among these amino acids, selection should be based on the heating temperature and anthocyanin profile of the product.

Establishment of anthocyanin fingerprint in black wolfberry fruit for quality and geographical origin identification

Black wolfberries (Lycium ruthenicum Murray) establish various biological activities, owing to anthocyanins, polysaccharides, pectin and so on. However, minor appearance differences are found in black wolfberries from different geographical origins. Thus, in this study, total phenolic content (TPC), total flavonoid content (TFC) and total anthocyanin content (TAC) were determined in black wolfberries from four provinces in China (Xinjiang, Qinghai, Gansu, Ningxia Provinces) for obtaining a distinguishable chemical index. Compared with TPC and TFC, TAC largely was affected by environment conditions, and thus, it may be a good chemical marker for geographical origin identification. Then, anthocyanin profiles were analysed by ultra-performance liquid chromatography (UPLC) coupled with triple quadrupole (triple Q)-time-of-flight mass spectrometry (TOF-MS), and principal component analysis (PCA) was applied for geographical origin identification based on anthocyanin fingerprints. A total of 17 anthocyanins were tentatively determined including two new individual anthocyanins, delphinidin-3-rutinoside (cis-p-coumaroyl)-5-O-diglucoside and delphinidin-3-rutinoside (trans-p-coumaroyl)-5-O-diglucoside. PCA indicated that individual anthocyanin contents calculated according to HPLC data and raw HPLC data both allowed a clear separation of geographical origins of black wolfberry fruits, explaining more than 95% of information of the samples. The present study could provide a scientific guidance for distinguishing the black wolfberry from different geographical origins.

Design of experiments (DoE) to model phenolic compounds recovery from grape pomace using ultrasounds.

Grape processing by-products (particularly grape pomace) are known to contain high amounts of phenolic compounds. To improve the extraction of phenols from this by-product, it is necessary to develop a method and set and model optimal conditions for their extraction. By applying the design of experiments (DoE) approach, optimal experimental factors of Ultrasound-assisted extraction (USAE) were determined to obtain grape pomace extracts with a satisfactory yield of phenols anthocyanins, as well as extracts with high antioxidant capacity using reagents approved in the food industry. Initial method optimization covered two experimental factors: solvent concentration and the weight ratio of the sample and solvent using fixed USAE conditions from literature. For the final method optimization, the three investigated experimental factors were: pH value, the temperature of extraction, and extraction time. The optimal experimental conditions for the development of the method were 55% ethanol, sample/solvent ratio 1:40, pH 4.5, T 55 °C, and 30 min. Depending on the primary goal of the extraction process (the antioxidant activity, total phenolic content, content of individual phenols, or content of individual anthocyanins), these parameters can easily be modified to obtain the desired recovery.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13197-021-05317-9.

Anthocyanins and Functional Compounds Change in a Third-Generation Snacks Prepared Using Extruded Blue Maize, Black Bean, and Chard: An Optimization.

The effect of extrusion cooking on bioactive compounds in third-generation snacks (TGSE) and microwave-expanded snacks (MWSE) prepared using black bean, blue maize, and chard (FBCS) was evaluated. FBCS was extruded at different moisture contents (MC; 22.2–35.7%), extrusion temperatures (ET; 102–142 °C), and screw speeds (SP; 96–171 rpm). Total anthocyanin content (TAC), contents of individual anthocyanins, viz., cyanidin-3-glucoside, malvidin-3-glucoside, pelargonidin-3-glucoside, pelargonidin-3-5-diglucoside, and delphinidin-3-glucoside chloride, total phenolic content (TPC), antioxidant activity (AA), and color parameters were determined. TAC and individual anthocyanin levels increased with the reduction in ET. ET and MC affected the chemical and color properties; increase in ET caused a significant reduction in TPC and AA. Microwave expansion reduced anthocyanin content and AA, and increased TPC. Extrusion under optimal conditions (29% MC, 111 rpm, and 120 °C) generated products with a high retention of functional compounds, with high TAC (41.81%) and TPC (28.23%). Experimental validation of optimized process parameters yielded an average error of 13.73% from the predicted contents of individual anthocyanins. Results suggest that the TGSE of FBCS obtained by combining extrusion and microwave expansion achieved significant retention of bioactive compounds having potential physiological benefits for humans.

Enhancement of anthocyanin and chromatic profiles in 'Cabernet Sauvignon' (Vitis vinifera L.) by foliar nitrogen fertilizer during veraison.

The influence of foliar nitrogen fertilizer during veraison (FNFV) on anthocyanin accumulation and chromatic characteristics of 'Cabernet Sauvignon' grapes over two seasons was investigated. Urea and phenylalanine fertilizers (TU and TP, respectively) and a control were sprayed three times at veraison. In 2018, TU displayed a significant enhancement in total individual anthocyanin content and a* and Cab * profiles. In 2019, FNAV significantly improved the content of total non-acylated, acylated anthocyanin and total individual anthocyanin, and the profiles of L*, a* and Cab *, except a* in TU. The whole process from phenylalanine variation to anthocyanin accumulation in grape skins was analyzed. On the whole, after the first FNFV to harvest, the increase in phenylalanine metabolism, abscisic acid content, effects of PAL (Phenylalanine ammonia lyase), UFGT (UDP glucose-flavonoid 3-O-glucosyltransferase) and transcript concentrations of VvPAL and VvUFGT involved in anthocyanin biosynthesis were also strong evidence explaining the increased anthocyanin and chromatic profiles in 2019. Overall, FNFV for nitrogen-deficient grapevines could significantly improve grape color, especially in the 2019 veraison with a proper climate. © 2021 Society of Chemical Industry.

Anthocyanin and Phenolic Acids Contents Influence the Color Stability and Antioxidant Capacity of Wine Treated With Mannoprotein.

Wine is consumed by humans worldwide, but the functional components are lost and the color changes during its production. Here, we studied the effects of mannoprotein (MP) addition (0, 0.1, and 0.3 g/L) upon crushing and storage. We measured anthocyanins, phenolic acids profiles, color characteristics, and antioxidant activities of wine. The results showed that the addition of MP before fermentation significantly increased the total phenolic content (TPC), total anthocyanin content, total tannin content (TTC), total flavonoid content, and total flavanol content in wine, whereas the addition of MP during storage had the opposite effect. The addition of MP before alcohol fermentation significantly increased the amount of individual anthocyanins and individual phenolic acids, maintained the color, and increased the antioxidant capacity of wine. In addition, the addition of 0.3 g/L MP during storage increased the content of individual phenolic acids and TPC of wine. However, the addition of 0.1 g/L MP during storage significantly reduced the TPC, TAC, TTC, and individual anthocyanin content (except for malvidin-3-glucoside and malvidin-3-acetly-glucoside); meanwhile, the treatment attenuated the color stability and antioxidant capacity of wine. The results demonstrated that the addition of MP before alcohol fermentation could increase the functional components and improve the color stability and antioxidant capacity of wine.

Differences in Anthocyanin Accumulation Profiles between Teinturier and Non-Teinturier Cultivars during Ripening.

Anthocyanins are vital components of plant secondary metabolites, and are also the most important coloring substances in wine. Teinturier cultivars are rich in anthocyanins. However, the differences in anthocyanin accumulation and profiles between teinturier and non-teinturier cultivars have not been reported. In this study, Yan 73 and Dunkelfelder were selected as the experimental materials, and three non-teinturier cultivars were used for comparison. LC-MS and qRT-PCR were used to determine the individual anthocyanin contents and the relative gene expression. The results show that the total anthocyanin content of the teinturier cultivars was considerably higher than that in non-teinturier cultivars, and the levels of individual anthocyanins increased gradually during ripening. Lower ratios of modified anthocyanins were found in the teinturier cultivars, which was not only due to the high expression level of VvUFGT and VvGST4, but also due to the relatively low expression of VvOMT in these cultivars. Cluster analysis of gene expression and anthocyanin accumulation showed that VvUFGT is related to anthocyanin accumulation, and that AM1 is related to the synthesis and transport of methylated anthocyanins. Our results will be useful for further clarifying the pathways of anthocyanin synthesis, modification, and transport in teinturier cultivars.

Anthocyanin profiles and color properties of red wines made from Vitis davidii and Vitis vinifera grapes

Spine grape (Vitis davidii Foex.) is an important wild grape species native to China. Fifteen red spine grape clones and three red Vitis vinifera grape varieties were used to evaluate the differences in the anthocyanin profiles and color properties of wines made from V. davidii and V. vinifera grapes. Among spine wines, ‘Junzi #2’ wine had the highest total phenolic and total anthocyanin, ‘Xiangzhenzhu’ wine had the highest total flavonoids, and ‘Junzi #1’ wine had the highest total tannin. The anthocyanin compositions of all of the spine wines were dominated by Mv-3,5-diglucoside. The total individual anthocyanin contents in spine wines, except ‘Gaoshan #5’, ‘Junzi #5055’, ‘Junzi #5061’, and ‘Junzi #5044’, were significantly higher than in V. vinifera wines. Most of the spine wines had a stronger red intensity and a brighter chroma with a bluer hue than V. vinifera wines. Correlation analysis revealed that the color properties were closely related to the anthocyanin composition. These results suggest that wines made from spine grapes may be useful for the wine industry for their color properties and high individual anthocyanin contents.

Review of Analytical Methods and Reporting of the Polyphenol Content of Tart Cherry Supplements in Human Supplementation Studies Investigating Health and Exercise Performance Effects: Recommendations for Good Practice.

Tart cherries (TC) are a rich source of polyphenols that elicit antioxidant and anti-inflammatory effects. As a consequence, the effects of TC derived supplements on markers of human health, exercise performance and sleep have been investigated. Supplementation protocols have been highly variable across studies and the dose of bioactive compounds used has often been poorly characterized. Specific and non-specific analytical methods were employed for measuring the total polyphenol and anthocyanin content in TC supplements. This review critically analyses the supplementation protocols and the analytical methods used for the characterization of TC supplements, culminating in recommendations for good practice in the analysis and reporting of the polyphenol content and profile of TC products. A literature search was conducted using PubMed/Medline and Web of Science up to May 4th, 2020, including studies published in all years prior. Only articles written in English that provided a TC dietary supplement as opposed to fresh whole TC were included in this review. Forty-three studies were identified as eligible and included for analysis in this review. The studies investigated the effects of TC supplementation on various aspects of human health, exercise recovery and performance and sleep. Twenty studies conducted an analysis of TC supplement and reported total polyphenol/anthocyanin content. Six studies did not report the polyphenol content of the TC supplement used. Seventeen studies reported the TC supplement polyphenol content but this was derived from previously published studies and presumably different supplement batches. The duration of the supplementation protocol ranged from acute supplementation to 84 days, meanwhile the total polyphenol and anthocyanin dose ranged from 143 to 2,140 mg/day and 15 to 547 mg/day, respectively. Due to the variety of specific and non-specific analytical methods used, the relative efficacy of different doses and polyphenol blends cannot reliably be extrapolated from critical analysis of the literature. Future studies should conduct an analysis of the study supplement batch. In addition to analysis and reporting of total polyphenol content, specific analytical methods such as HPLC UV/MS should be used to quantify total and individual anthocyanin contents.

The Influence of the Production Process on the Anthocyanin Content and Composition in Dried Potato Cubes, Chips, and French Fries Made from Red-Fleshed Potatoes

The stability of acylated anthocyanins is still a new and unexplored subject of study. The changes in the contents of individual anthocyanins in colored-flesh potato tubers during processing have rarely been addressed in the literature. The aim of the present study was to determine how anthocyanin degradation and profiles are influenced in potatoes of the red-fleshed Herbie 26 variety by different methods of processing. Potato samples were divided into four categories to be analyzed, namely, raw material, potato cubes, French fries, and chips. The dried cubes, French fries, chips, semi-finished products, and finished products, obtained through laboratory processing, were examined for anthocyanin content and composition. The production process of cubes, chips, and French fries led to losses of the examined anthocyanins; however, these losses differed depending on the technological stage. The greatest losses of these compounds were determined after the final production processes, i.e., pre-frying, frying, and drying. Chip production led to the lowest losses of anthocyanins. Omitting the blanching stage in chip production allowed the retention of more anthocyanins. Pelargonidin-3-feruloylrutinoside-5-glucoside, having the highest percentage in the raw material (approximately 50%), followed by pelargonidin-3-caffeoylrutinoside-5-glucoside, proved to be the most thermally stable.

Variation in anthocyanins of different varieties of purple carrots

The composition and content of anthocyanins were investigated in nine varieties of purple carrots to reveal the diversity of the anthocyanins among different varieties of purple carrots. The results showed the significant differences of the composition and content of anthocyanins were found between nine varieties of purple carrots. Five anthocyanins were detected in purple carrots, including cyanidin 3-xylosyl(glucosyl), cyanidin 3-xylosylgalactoside, cyanidin 3-xylosyl (sinapoylglucosyl)galactoside, cyanidin 3-xylosyl(feruloylglucosyl)galactoside, and cyanidin 3-xylosyl(coumaroylglucosyl)galactoside. Only four of the five anthocyanins were detected in Caohaihong, Zhongzidan, and Yanzi, whereas 3-xylosyl(coumaroylglucosyl)galactoside were not detected. The highest content of total anthocyanins was found in Tianzi. In addition, the highest contents of individual anthocyanins except for cyanidin 3-xylosyl(sinapoylglucosyl)galactoside, were also in Tianzi, and the highest content of 3-xylosyl(sinapoylglucosyl)galactoside was found in Zishengzi. In summary, these findings provide a theoretical reference for the scientific consumption and a foundation for the further study of purple carrots in the future.

Reflective mulch increases fruit yield of highbush blueberry (Vaccinium corymbosum L. cv. Darrow) grown in a northern maritime environment while maintaining key fruit quality traits.

In maritime growing environments, blueberry yield often exhibits excessive season-to-season variation, associated with poorly adapted photosynthetic responses to low light conditions. It is therefore necessary to develop methods that stabilise yield while maintaining or improving fruit quality. Here, we placed reflective mulch alongside plants at the early green fruit stage, to test the hypothesis that increasing the available seasonal light integral could enhance blueberry yield. We further determined several quality characteristics to ensure fruit marketability. Placement of mulch alongside plants reflected up to five times more light compared with bare ground, enhancing the amount of light reaching the canopy. This led to an adaptive increase of light saturated maximal photosynthetic rate of mulch-treated plants, resulting in a twofold increase in yield compared with control plants. Analysis of fruit quality characteristics showed that total soluble solids, sugars and organic acids were similar between treatments. Likewise, antioxidant capacity, total anthocyanin content and the content of individual anthocyanins did not change in response to reflective mulch treatment. The use of reflective mulch should be explored by industry as a cost-effective method for enhancing blueberry yield while maintaining fruit quality in maritime environments. © 2020 Society of Chemical Industry.

Impact of oak (<i>Q. pyrenaica</i> and <i>Q. pubescens</i>) and cherry (<i>P. avium</i>) wood chip contact on phenolic composition and sensory profile evolution of red wines during bottle storage

The majority of published work has studied the impact of wood chips on red wine composition by conducting analyses during wood chip contact or immediately after the removal of chips from wine. Less attention has been directed at the potential influence of prior chip-wine contact on the further phenolic and sensory evolution of red wines during bottle storage. Therefore, this work focuses on the evolution over a period of 18 months of several phenolic parameters and sensory characteristics of bottled Touriga Nacional red wines that had previously been in contact with toasted wood chips from cherry (Prunus avium) and two oak species (Quercus pyrenaica and Quercus pubescens) during 30 days of pre-bottling storage. Various global phenolic parameters, colour properties, individual anthocyanin content and sensory profile of the wines were studied at 6, 12 and 18 months of bottle storage. The results showed less decrease in the phenolic composition and red colour of wines which had prior contact with oak chips, as well as a less developed brown colour during bottle storage, compared to the wine previously in contact with cherry chips and the control wine. In addition, wine previously in contact with cherry chips always showed an evolution similar to the control wine. From a sensory point of view, the wines previously in contact with oak wood chips showed a tendency for higher aroma scores for “vanilla” and “coconut” descriptors and lower scores for “brown colour” during bottle storage than wines previously in contact with cherry chips and the control wine. The outcomes of this research could be of practical interest to winemakers since they could improve the knowledge of the impact of prior contact with wood chips in the future evolution of the red wines during bottle storage.

Stability and Antiglycoxidant Potential of Bilberry Anthocyanins in Simulated Gastrointestinal Tract Model.

Anthocyanins from Vaccinium myrtillus fruits have been reported in vitro to exert potent radical scavenging and antiglycation activities. However, the physiological relevance of such properties remains unclear given the potential susceptibility of anthocyanin derivatives to digestive conditions. A simulated gastrointestinal tract model was thus implemented to assess the impact of gastric and intestinal phases on the chemical integrity of bilberry anthocyanins and their antiglycoxidant effects. Results demonstrated that the investigated activities as well as total and individual anthocyanin contents were marginally affected by gastric conditions. By contrast, with recoveries ranging from 16.1 to 41.2%, bilberry anthocyanins were shown to be highly sensitive to the intestinal phase. Of major interest, a much better preservation was observed for radical scavenging and antiglycation activities as attested by recovery rates ranging from 79.1 to 86.7%. Consistently with previous observations, the present study confirms the moderate bioaccessibility of anthocyanin constituents. It does however provide valuable information supporting the persistence of substantial radical scavenging and antiglycation activities at each step of the digestion process. Taken together, these data indicate that digestive conditions might not abolish the potential positive effects of bilberry consumption on both oxidative and carbonyl stresses.

Insights into exogenous melatonin associated with phenylalanine metabolism in postharvest strawberry

Melatonin is a kind of multifunctional hormone, analogous to indoleacetic acid in structure. To uncover the relationship between exogenous melatonin and the phenylalanine pathway, the liquid chromatography mass spectrometry (LCMS) was performed to quantify endogenous melatonin and individual anthocyanin content. RT-qPCR was used to explore the expression of primary genes involved in anthocyanin biosynthesis. In the present study, we found that the morphology and endogenous melatonin content of strawberries showed a significant improvement and increase in the M50 compared with the other groups. Additionally, anthocyanin accumulation and genes up-regulation, in both the M50 and the M100, all revealed higher levels than that of the control. In conclusion, this work revealed the positive relationship between exogenous melatonin and the phenylalanine metabolism of strawberries.