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• Red wines had up to 60 times higher levels of phenolic compounds than white wines. • Hydroxycinnamic acids were a characteristic of white wines. • Anthocyanins were responsible for the highest variations between varieties. • Epicatechin and some phenolic acids could be a terroir characteristic of Fruška Gora. • Domestic and autochthonous Fruška Gora varieties showed great biological potential. This paper presents a comprehensive study of commercially available monovarietal red and white wines from Fruška Gora mountain in Serbia, conducted to characterize their chemical and biochemical properties. Namely, 72 wines of 18 different Vitis vinifera varieties, including international, domestic and autochthonous ones, were assessed. Phenolic profile of wines was determined qualitatively, using spectrophotometric methods, and quantitatively, using LC-MS/MS and HPLC-UV/VIS methods. Quantified phenolic compounds pointed out differences between red and white wines, where some compounds stood out as distinctive characteristic of analyzed varieties, while others served as chemotaxonomic markers of the Fruška Gora region. Antioxidant and inhibitory properties towards acetylcholinesterase were evaluated for all wines and their relation to phenolic composition was investigated. This study is valuable since chemical and biochemical properties of domestic and autochthonous Fruška Gora varieties are reported for the first time. Also, international varieties studied herein gave distinctive information about the terroir of Fruška Gora region, which is scarce in scientific literature. [ABSTRACT FROM AUTHOR]

UV-C irradiation can maintain fruit quality by inducing fruit disease resistance and reducing decay during storage. Grape (Vitis Vinifera L.) was exposed to 2.4 kJ m−2 UV-C irradiation then inoculated with Aspergillus carbonarius to investigate the changes in nutritional quality, defense related substances and enzyme activities. Postharvest UV-C irradiation can increased the levels of defense-related substances and enzyme activities, such as phenols, flavanols, lignin, proline, glutathione, phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and β-1,3-glucanase (GLU). In addition, Resveratrol plays an important role in grape resistance to A. carbonarius infection through further verification by gene expression levels, the transcription factors VvWRKY24 and VvMYB14 are highly correlated with the regulation of VvSTS gene expression. This study revealed the molecular mechanism of postharvest grape fruit response to UV-C irradiation and the defense mechanism against black rot, and provided a theoretical basis for postharvest grape storage and preservation technology. • UV-C irradiation maintained storage quality of grapes. • UV-C irradiation induced resistance against A. carbonariu. • UV-C irradiation elevated activity of defense-related enzyme and phenolics content. • UV-C irradiation accelerated the biosynthesis of phenolic substances. • Resveratrol was a important defense substance during resistance induction. [ABSTRACT FROM AUTHOR]

Botrytis cinerea causes gray mold, decreasing the quality of table grapes. The berry response to B. cinerea infection was explored in present study, focusing on the relationship between presence of autophagy and programmed cell death (PCD). Results demonstrated B. cinerea infection decreased cell viability, triggering cell death, possibly resulting in PCD occurrence. It was further verified by increased terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive nuclei, heightened caspase 3-like and caspase 9-like protease activity, and elevated expression of metacaspase genes. Additionally, autophagy was indicated by the increased VvATG expression and autophagosome formation. Notably, the autophagy activator rapamycin reduced TUNEL-positive nuclei, whereas the autophagy inhibitor 3-methyladenine increased caspase 9-like protease activity. The PCD activator C2-ceramide inhibited autophagy, whereas the PCD inhibitor Acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO) enhanced autophagy gene expression. Autophagy and B. cinerea -induced PCD in berry cells are reciprocally negatively regulated; and the rapamycin and Ac-DEVD-CHO could potentially maintain table grape edible quality. • B. cinerea infection impaired grape berry skin cell viability and induced PCD. • Elevated caspase 3-like and 9-like activities signaled B. cinerea -induced PCD. • B. cinerea infection enhanced autophagosome formation and VvATG expression. • Autophagy and B. cinerea -induced PCD reciprocally inhibited in skin cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Proanthocyanidins profiles of Nero d'Avola and Grillo wines were determined. • Soil chemical-physical parameters affect the proanthocyanidins composition of the wines. • Soil parameters related to nutrient dynamics affect tannin composition in Nero d'Avola red wines. • Soil parameters related to water dynamics affect tannin composition in Grillo white wines. In this study, the effects of the main soil chemical-physical parameters (i.e. texture, pH, total carbonates, cation exchange capacity, electric conductivity, organic matter and mineral endowment) on proanthocyanidin composition of Nero d'Avola red wines and Grillo white wines were investigated. Monomer proanthocyanidins (i.e. (+)-catechin and (-)-epicatechin) and oligomer proanthocyanidins (i.e. B1, B2, B3 and B4 dimers and C1 trimer), as well as proanthocyanidins subunit composition, percentage of galloylation, percentage of prodelphinidins and mean degree of polymerization, were studied for each wine. Results highlighted that the proanthocyanidins composition of both red and white wines is greatly affected by soil. In particular, the proanthocyanidins composition of Nero d'Avola red wines appeared to be affected by the soil physical–chemical parameters related to nutrients dynamics (CEC, EC, pH, organic matter, mineral endowment), whereas the proanthocyanidins composition of Grillo white wines was mainly influenced by the soil texture, that modulates soil water dynamics. [ABSTRACT FROM AUTHOR]

• Vitis vinifera 'SuoSuo' a traditional medicine and food homologous plant in Xinjiang, was used as the test material. • Targeted metabolomics was used to determine the metabolism of anthocyanins, sugars and organic acids in 'SuoSuo' grapes. • The anthocyanins in 'SuoSuo' grapes were dominated by cyanidin-3-O-glucoside, fructose was the major sugar, and tartaric acid was the major organic acid. • Oleanolic acid was found in 'SuoSuo' grapes. In this study, targeted metabolomics technology was used to accurately and quantitatively analyze the metabolic pathways of anthocyanin, sugars and organic acid metabolites during the ripening of 'SuoSuo' grape berries. Results, 33, 10 and 36 metabolites of anthocyanins, sugars and organic acids, respectively, were detected. The anthocyanin with the highest content was cyanidin-3-O-glucoside (136.343 ng/g), which reached a maximum at 135 days after full bloom. The highest fructose content in sugar was 167.69 ng/g (135 days after full bloom). Among the organic acids, tartaric acid exhibited the highest content (37,196.67 mg/kg, 105 days after full bloom). The content of oleanolic acid (230.064 mg/kg, 135 days after full bloom) was higher in organic acids. These results clarify how anthocyanin, sugar and organic acid metabolites accumulate and change as 'SuoSuo' grapes ripen and provide a reference for the development and utilization of 'SuoSuo'. [ABSTRACT FROM AUTHOR]

• Light irradiation enhanced the color index and inhibited the respiration rate. • Light irradiation enhanced the adenosine triphosphate and adenosine diphosphate. • Light irradiation improved the energy charge and inhibited adenosine monophosphate. • Light irradiation inhibited chlorophyll degrading enzyme activity. • Light irradiation boosts anthocyanin biosynthesis enzyme and energy metabolism activities. Grape is the world's economic horticultural crop; it is perishable due to various pathogens and abiotic stress attributed to water loss-induced issues. To address these postharvest problems, this research investigates the effects of light irradiation on anthocyanins synthesis and energy metabolism in stored grapes to enhance their postharvest quality. The activities of chlorophyllase (1.17 U gk−1), Mg-dechelatase (351.69 U gk−1), chlorophyll-degraded peroxidase (3.49 U gk−1), and pheophytinase (0.85 U gk−1) were significantly higher in the control fruit than in the treated fruit at the end of storage. The red-light treatment showed higher levels of anthocyanins biosynthesis-related enzymes than green, blue-light, and control treatments. Additionally, light irradiation resulted in a decrease in adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, and energy charge. This was attributed to decreased activity of energy metabolism enzymes, reduced nicotinamide adenine dinucleotide phosphate content, and increased nicotinamide adenine dinucleotide content. These findings offer a theoretical foundation for optimizing grape coloration and energy metabolism during storage, thus prolonging the shelf-life of grapes by improving quality attributes. This research highlights the potential of light irradiation as a technique for enhancing the postharvest quality of agricultural products. [ABSTRACT FROM AUTHOR]

• Phenolic composition of two novel Vitis vinifera red grapes was studied. • These Vitis vinifera red grapes were compared to Tempranillo cultivar. • More than 50 phenolic compounds were quantified by HPLC-DAD-ESI-MS/MS. • New anthocyanin and flavonol diglucosides were reported in Vitis vinifera grapes. • Phenolic profile of grape skins and seeds allowed varietal differentiation. The detailed phenolic composition of different berry parts from two novel V. vinifera L. red grape genotypes (Moribel and Tinto Fragoso), together the well-known Tempranillo, was established using high performance liquid chromatography-diode array detection-electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI-MS/MS) over two consecutive vintages (2016 and 2017). More than 50 phenolic compounds were identified and quantified: 25 anthocyanins, 17 flavonols, 7 hydroxycinnamic acid derivatives, 2 stilbenes, and several flavan-3-ols. As far as we know, some anthocyanin and flavonol dihexosides were reported for the first time in V. vinifera L. grapes. Application of Principal Component Analysis (PCA) to experimental data showed a good separation of the novel grape genotypes and Tempranillo according to the phenolic profile of skins and seeds, mainly based on the proportion of trisubstituted anthocyanin derivatives, flavonols and flavan-3-ols, being a useful tool to differentiate these grape varieties. [ABSTRACT FROM AUTHOR]

Sauvignon blanc grape samples (n = 21) from across a single Geographical Indication of South Australia were analysed for thiol precursors and amino acids, and fermented in an identical laboratory-scale fermentation trial to investigate the intraregional pattern of varietal thiols in the wines. Precursors and thiols exhibited obvious intraregional diversity, and notably, stronger correlations were observed between a number of amino acids and thiol precursors (especially with glutamic acid, r ≤ −0.73) rather than free thiols. Additionally, pre-fermentation freezing (−20 °C, 1 month) was applied to five selected fresh grape samples and their juices, followed by identical fermentation. In comparison to wines from fresh grapes or frozen juices, significant elevation of varietal thiols (up to 10-fold) occurred in the wines derived from frozen grapes, with parallel increases of precursors (up to 19-fold) in juices from frozen berries. These novel results may lead to new strategies for thiol enhancement during winemaking. [ABSTRACT FROM AUTHOR]

• Moldova contained lowest content of volatile esters. • The composition of volatile esters in Campbell Early and Catawba were different. • AAT gene mainly determined the contents of volatile esters. • Precursors and precursor genes also alter biosynthesis of volatile esters. This study investigated the accumulation of esters in three hybrid grape cultivars during berry development under two vintages to elucidate the differentiation on their esters biosynthesis. Results showed 'Moldova' showed lower esters content than 'Campbell Early' and 'Catawba' resulting from its limited AAT gene expression and 20 different encoded amino acids. The volatile esters compositions of 'Campbell Early' and 'Catawba' in both vintages were different. Correlation analysis revealed that concentrations of hexyl acetate, 2-phenethyl acetate, ethyl (E,E)-2,4-hexadienoate and ethyl phenylacetate were related to their corresponding alcohols level, whereas threonine and alanine affected ethyl heptanoate formation. Transcriptome analysis indicated that 1847, 1781 and 1870 DEGs, at E-L 35, 36 and 38, respectively, were characterized between 'Campbell Early' and 'Catawba'. The expression level of genes related to the volatile ester precursors biosynthesis, including PRX-VIT_211s0016g05320 , PAO-VIT_217s0000g09100 , ACOX-VIT_212s0028g02660 , ACOX-VIT_216s0022g01120 , echA-VIT_205s0077g00860 and ACOX-VIT_200s0662g00010 , exhibited a positive correlation to the concentrations of their corresponding volatile esters. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metabolomics & metabarcoding were performed in 3 grapevine cultivars. • Dothideomycetes and Gammaproteobacteria are main drivers of cultivar differentiation. • Over 7000 metabolite-microbiota correlations with ρ >|0.99| were exposed. • 15 metabolites & 11 taxa form the main clusters of metabolite-microbiota correlations. • E. necator and A. carbonarius correlate negatively with wax-related compounds. This study hypothesized the existence of cultivar-associated correlations between grape berry metabolites and its microbial residents, in Douro wine region. Integrated metabolomics with metabarcoding showed that the microbial biodiversity is not associated to berry sugar concentration, but closely connected to the profile of amino acids, flavonoids and wax compounds, which drove cultivar differentiation together with the prevalence of pathogenic fungi, yeasts and bacteria, mainly Dothideomycetes and Gammaproteobacteria. Over 7000 metabolite-microbiota correlations with ρ >|0.99| exposed a core of 15 metabolites linked to 11 microbial taxa. Serine, oxalate, cyanidin-3- O -glucoside, petunidin-3- O -glucoside, gallic acid, germanicol, sitosterol and erythrodiol correlated negatively to the abundance of most taxa, including Alternaria , Aureobasidium , Pseudopithomyces , Pseudomonas and Sphingomonas. In contrast, phenylalanine, asparagine, alanine, (epi)gallocatechin and procyanidin gallate mediated positive metabolite-OTU correlations. E. necator and A. carbonarius correlated negatively with stigmasterol and amyrin. Complex fungi-bacteria relationships ruled by Dothideomycetes and Alphaproteobacteria further suggest tight host-microbe interactions at the carposphere. [ABSTRACT FROM AUTHOR]

• Seeds did not influence extracted grape skin anthocyanins in simulated maceration. • The compounds extracted from seeds increased the share of polymeric pigments. • Grape seed surface adsorbs anthocyanin compounds extracted from skins. • Varietal characteristics influence anthocyanin adsorption on seed surface. The impact of seeds on anthocyanin extraction from skins was assessed on four Italian red winegrape varieties presenting different anthocyanin profile. Grape skins were macerated alone or in presence of seeds for ten days in model solutions. Aglianico, Nebbiolo, Primitivo, and Sangiovese cultivars showed differences in the anthocyanin extraction rate, content, and profile. The presence of seeds did not significantly affect the anthocyanin content and forms extracted from skins and kept into solution, but it generally led to an increase in the polymerization rate. For the first time, anthocyanins adsorbed on seed surface have been quantified after maceration. The amount of anthocyanins retained by seeds was less than 4 mg/kg berries and it seems variety-dependent, with a possible role of seeds number and weight. Individual anthocyanin forms were adsorbed mainly according to their abundance in the solution, but cinnamoyl-glucoside anthocyanin forms showed a higher affinity with seed surface. [ABSTRACT FROM AUTHOR]

• Berry anthocyanin contents were increased due to dehydration. • PLS regression revealed the components which influenced the color. • Berry and wine aroma profiles were influenced by harvest date. • PCA could discriminate wines according to different harvest date. The ripeness of a grape is critical to berry composition and to the resultant wine. For wineries with a single cultivar occupying an extensive area, the total soluble solid of grapes can range from 22°Brix to 28°Brix. Accordingly, the influence of different harvest dates (ripeness) on berry compositions and on the resultant wine profile was investigated for Vitis vinifera L. cv. 'Cabernet Sauvignon.' Berry dehydration was observed as berry weight and juice yields decreased. Berry anthocyanins were concentrated and methylated anthocyanin levels fluctuated with increasing delays in harvesting. Hexanal and 2-hexenal levels in must decreased significantly as berries ripened. In the resultant wines, 2,3-butanediol levels increased. Wines harvested earlier were lighter, presented lower color intensity (CI) values and higher yellow% levels, and exhibited richer aroma profiles (compounds). Through a principal component analysis and discriminant analysis, the compounds characterizing each harvest date were identified. [ABSTRACT FROM AUTHOR]

Highlights • Vine-shoot fragments as enological additives. • Granule and chip formats in different dosages and maceration times were tested. • Significant release of volatile and phenolic compounds were quantified. • Vanillin and guaiacol thresholds were overcome. • Ellagic acid and trans -resveratrol content higher due to vine-shoot treatments. Abstract For the first time, the possibility of using vine-shoots as enological additives, similar to oak chips, is proposed. Their volatile and phenolic compounds contribution to a model wine was studied. Variables such as vine-shoot vinifera (Airén and Cencibel), size (chip and granule), toasting (toasted and non-toasted), dosage (4 and 12 g/L) and maceration time (1, 7, 21, 35 and 120 days) were tested. Results showed an important transference of high-value enological compounds after 35 days of maceration with 12 g/L of toasted vine-shoots. Vanillin or guaiacol were found in concentrations always higher than their wine odor thresholds, depending on the variety and vine-shoot formats used. Moreover, trans -resveratrol and ellagic acid stand out for their high concentrations. This transference rate shows the enological aptitude of vine-shoots with a possibly positive contribution in real wines, both at sensory and functional level, although future studies in real wines must be carried out. [ABSTRACT FROM AUTHOR]

Highlights • Profiles of terpene compounds in Meili grape and wine were revealed. • Bound terpene compounds were quantified as aglycone-pentosyl-glucopyranoside. • Contribution of terpene compounds to Meili wine aroma was explored. • A molecular rearrangement of terpene aglycones in Meili grape and wine was discussed. Abstract The chemical profiles and aroma contribution of terpene compounds in Meili grapes and wine were analyzed. Bound terpene compounds were extracted using methanol, purified using Amberlite XAD-2 resin, concentrated in methanol/ethyl acetate, and enzymatically hydrolyzed to release aglycones. Free terpene compounds were identified using solid-phase microextraction (SPME) coupled with gas chromatography–mass spectrometry (GC–MS). Wine aroma characteristics were quantified by a trained sensory panel. Seventeen terpene glycosides were quantified in grapes and wines as pentosyl-glucopyranoside, the content of which ranged from 804 to 836 μg/kg, and from 155 to 192 μg/L, respectively. Eight free terpenes were present in wines with their content ranging from 40.1 to 59.7 μg/L. Linalool was abundant both in bound and free terpenes, and mathematical regression revealed that terpenes, especially linalool (contribution efficient > 0.4), contributed heavily to Meili wine aroma. Finally, a molecular rearrangement scheme based on linalool was proposed in Meili grape and wine. [ABSTRACT FROM AUTHOR]

Highlights • Fertigation effects on chemical composition of Albariño were studied. • Volatiles were influenced by fertigation treatments. • A trend to increase the volatiles was observed when fertigation treatment was applied. • A higher vintage effect was also observed. Abstract Vineyard management can influence the growth and yield components in the vineyards and therefore on the grape and wine quality. In this work, a chemical study was conducted (2014–2015) to examine the effect of fertigation on chemical composition of Albariño. A control (Rain-fed) and fertigation (60% and 100%) treatments were apply at same irrigation depth, where fertigation 100% is complete nutrient requirements to Albariño trellis system in this location (Rias Baixas AOC, NW Spain). Results showed that non-volatile compounds of Albariño musts were not affected by fertigation treatments. However, the effect of fertigation treatments on the volatile composition was observed. Terpenes and C 13 -norisoprenids were the most affected families of volatile compounds by fertigation treatments, where 60% fertigation exhibited the highest concentration, improving the wine aroma quality. Application of principal component analysis (PCA) showed a good separation of Albariño grape according to fertigation treatments and vintages. [ABSTRACT FROM AUTHOR]

Highlights • Malvidin 3-feruloyl-glc was identified in all skin, wine and pomace samples of Tannat. • The p -coumaroyl-derivatives were poorly extracted from grape to wine. • Caffeoylated-anthocyanin synthesis would take place during vinification. • Methoxylated anthocyanins would be less extractable but more stable in wines. • The pomace retained methoxylated and acylated pigments which are particular stable. Abstract The purpose of this investigation was to assess the grape pigment extraction during red-winemaking. The pigment content and profile of skin, wines and pomace of Vitis vinifera grapes with different pigment profiles Syrah, Marselan and Tannat was thoroughly studied. The p -coumaroylated anthocyanin proportions were 37% in pomace, compared to 19% in skins and just 5% in wines, highlighting their poor extraction. Di-methoxylated based anthocyanins, increased their relative contribution in pomace and wines compared to skins, indicating they were less extracted, but more stable once extracted. Remarkably, the caffeoylated anthocyanins presented significantly higher concentrations in pomace than in skins (1.9 fold on average), suggesting that their synthesis could take place during vinification. Malvidin 3-feruloyl-glucoside was found in the Tannat samples being the first evidence of an anthocyanin acylated with ferulic acid in wine. Pigment extraction was selective depending on anthocyanin B-ring substitution pattern and acylation profile. [ABSTRACT FROM AUTHOR]

Highlights • Defense-related proteins of H. uvarum were up-regulated by trehalose treatment. • Stilbene synthase of grapes was up-regulated by trehalose treated H. uvarum. • Defense enzymes of grapes were activated by H. uvarum Y3. Abstract This present study tested the extent to which 2% w/v trehalose enhanced the proteins expression profile of Hanseniaspora uvarum Y3. Furthermore, it explored the relative gene expression of stilbene synthase (StSy), one of the vital defense-related genes found in the skin of grapes. The proteomics profile revealed that 29 proteins were differentially expressed out of which 26 were significantly up-regulated and 3 were download-regulated. The pathogenesis related (PR) and other protein spots were visible at 97.4 kDa and 14.4 kDa. Peroxiredoxin TSA1 and superoxide dismutase were the main proteins involved in defense response and both proteins were significantly up-regulated. The carbohydrate and energy metabolism proteins were also significantly up-regulated. The results revealed that the treatments were associated with substantial increase in peroxidase activity compared to the control. StSy relative gene expression level was observed to increase by 2.5-fold in grapes treated with the pre-enhanced H. uvarum compared to the control. [ABSTRACT FROM AUTHOR]

• Predictive models developed for B. cinerea infection levels from volatile profiles. • Predicted infection levels assessed by measuring ergosterol and antigen detection. • Key markers of infection (trans -2-octen-1-ol, 3-octanol, 1,5-dimethyltetralin) • Volatile metabolites tracked during the early stages of B. cinerea infection. Infection of grape berries (Vitis vinifera) by the fungus Botrytis cinerea (grey mould) frequently occurs in vineyards, resulting in off-flavours and other odours in wine and potential yield losses. In this study, volatile profiles of four naturally infected grape cultivars, and laboratory-infected grapes were analysed to identify potential markers for B. cinerea infection. Selected volatile organic compounds (VOCs) were highly correlated with two independent measures of B. cinerea infection levels, demonstrating that ergosterol measurements provide accurate quantification of lab-inoculated samples, while B. cinerea antigen detection is more suitable for naturally infected grapes. Excellent predictive models of infection level were confirmed (Q2Y of 0.784–0.959) using selected VOCs. A time course experiment confirmed that selected VOCs 1,5-dimethyltetralin, 1,5-dimethylnaphthalene, phenylethyl alcohol and 3-octanol are good markers for B. cinerea quantification and 2-octen-1-ol could be considered as an early marker of the infection. [ABSTRACT FROM AUTHOR]

Flavonoids are important compounds for grape and wine quality. Foliar fertilization with iron compounds has been reported to have a substantial impact on grape composition in the grapevines growing in calcareous soil. However, much less is known about its real impact on flavonoid composition. In the present study, Ferric ethylenediamine di (O-hydroxyphenylacetic) acid (Fe-EDDHA) was foliar applied to Merlot ( Vitis vinifera L.) grapevines growing in calcareous soil over two consecutive vintages in order to study its effect on grape flavonoid composition. Fe-EDDHA foliar supply tended to increase grape sugar, anthocyanin and flavonol content, decrease acid content and enhance the juice pH when compared to the control. Principal component analysis showed that the vintage also had influence on grape quality. The results suggested that Fe-EDDHA foliar application had an enhancement effect on grape secondary metabolism, and the effect increased the nutritional value of the consequent grapes and wines. [ABSTRACT FROM AUTHOR]

The red wines made from Vitis vinifera were identified as skin-whitening effectors by using in vitro assays. OPCs in the wine were evaluated for tyrosinase activity and melanogenesis. Strong tyrosinase inhibitory activity was observed in fractions with high oligomeric proanthocyanidin (OPC) content. Among OPC dimers, a strong inhibitory effect on tyrosinase was observed with OPCs which contain (+)-catechin as an upper unit. Melanogenesis inhibitory effect was observed with OPCs which have (-)-epicatechin as upper units. Also, OPC trimers, upper and middle units joined with 4 → 8 bonds, showed stronger effects compared to trimers with 4 → 6 linkages. Interestingly, (-)-epicatechin-(4β → 8)-(-)-epicatechin 3- O -gallate, which is a unique component of grapes has potent inhibitory effects on both tyrosinase and melanogenesis. Our data provide structural information about such active compounds. These results suggest that red wines containing OPC, have high melanogenesis inhibitory effect and are supposed to have skin-whitening effect. [ABSTRACT FROM AUTHOR]

Methyl jasmonate (MeJA) was applied in a vineyard on leaves and grape clusters of cv Sangiovese to test its ability to stimulate the production of aromas and identify the main genes involved in the biosynthetic pathways switched on by the elicitor. MeJA application led to a delay in grape technological maturity and a significant increase in the concentration of several berry aroma classes (about twice the total aroma: from around 3 to 6 μg/g of berry). Of these, monoterpenes showed the most significant increase. An analysis of the expression of terpenoid biosynthesis genes confirmed that the MeJA application activated the related biosynthetic pathway. The expression of all the TPS genes analyzedwas higher in samples treated with MeJA. Also the wines produced by microvinification of Sangiovese treated and untreated grapes showed a rise in the aroma concentration as in berries, with an important impact on longevity and sensorial characters of wines. [ABSTRACT FROM AUTHOR]

Nitrogen is an important element for grapevine and winemaking, which affects plant development, grape juice fermentation and has a potential effect in modulating wine quality. The aim was to study the influence of foliar applications of riboflavin (vitamin B2) to vineyard on grape nitrogen composition. This vitamin has a reported capacity to protect different plant species, but its application to favor grape and grape juice quality had not previously been studied. This work reports the oenological properties and the effect on amino acid concentration of grape juices obtained from grapes treated with riboflavin at two different doses compared to control. Results showed that probable alcohol, malic acid, color intensity and hue had significant differences when the riboflavin treatments were applied. Most of the amino acids presented the highest concentrations when the lowest riboflavin dose was used. These results are promising in terms of fermentation development and grape juice nitrogen composition. [ABSTRACT FROM AUTHOR]

Six table grape cultivars (Centennial Seedless, Chasselas, Italia, Italia Rubi, Alphonse Lavallée, and Muscat de Hambourg) were analyzed for their levels of soluble solids, titratable acidity, sugars, organic acids, vitamin C and E, carotenoids, polyphenolics and volatile compounds during two successive years. Descriptive sensory analyses of the six table grape varieties were also performed. Mainly due to anthocyanins, black cultivars had the highest total phenolic contents. Alphonse Lavallée had also both the highest levels of trans -resveratrol and piceid, and Muscat de Hambourg the highest levels of α-tocopherol, β-carotene and monoterpenols, well-known key aroma compounds in Muscat varieties having also interesting pharmacological properties. This study shows that the two traditional black French cultivars, Muscat de Hambourg and Alphonse Lavallée, are particularly rich in bioactive compounds and have a great potential for human health. Finally, Muscat de Hambourg was significantly rated sweeter, juicier and more aromatic than the others cultivars. [ABSTRACT FROM AUTHOR]

Stilbenoids, in particular, resveratrol and its dimers are abundantly present in Vitis vinifera and proved to be quenchers with selective singlet oxygen. However, only a few mechanisms are reported for their complex molecular architectures. Hence, UHPLC combined with accurate MS is employed to investigate the photo-radiation mechanism of resveratrol dimers systematically. Ⅰ: Resorcinol ring exists in Scirpusin A 1 , Trans -ε-viniferin 2 and Trans -σ-viniferin 3 . The photochemical products were 14 Da or 16 Da higher than reagents and underwent an endoperoxide intermediate to quinones; Ⅱ: [2+2] cyclization of intra-molecular trans-double bond. The products were 18 Da greater than substrates thereby cycloaddited to oxygen heterocyclic; Ⅲ : [4+1], [4+2] cyclization of oxetane formed products were 28 Da and 44 Da higher than 3 , 2 and 1 . Ⅳ : 5-phenol-2,3-dihydrobenzofuran ring exists in 2 been oxidized, causing the products at 16 Da, 32 Da higher than 2 . This is the first to reveal the generally regular mechanism of stilbenoids quenching singlet oxygen. [ABSTRACT FROM AUTHOR]

The effect of temperature on the degradation of anthocyanins in juçara and “Italia” grape extracts was determined between 50 and 90 °C. For both species, thermal degradation followed a first-order kinetic model. The decimal reduction time decreased with increasing temperature, and dependence on the thermodegradable factor was lower at higher temperatures. The anthocyanins from juçara degraded more slowly than those extracted from “Italia” grapes. The activation enthalpy and free energy of inactivation indicated an endothermic reaction, not spontaneous degradation, whereas the activation entropy suggested that the transition state has less structural freedom than that of the reactants. The antioxidant capacity of the extracts was reduced when subjected to 90 °C heat treatment, however, significant quantities of this bioactive compound still remained. [ABSTRACT FROM AUTHOR]

• Application of forchlorfenuron N–(2–chloro–4–pyridinyl)–N′–phenylurea (CPPU) was associated with increased berry size and firmness. • Forchlorfenuron N–(2–chloro–4–pyridinyl)–N′–phenylurea (CPPU) was associated with increased glycolysis and TCA cycle-related proteins. • Forchlorfenuron N–(2–chloro–4–pyridinyl)–N′–phenylurea (CPPU) was associated with modified accumulation of sugars and organic acids. Consumers around the world prefer high quality table grapes. To achieve higher quality traits at ripening, grapevine producers apply different plant growth regulators. The synthetic cytokinin forchlorfenuron N–(2–chloro–4–pyridinyl)–N′–phenylurea (CPPU) is widely used, its effect on grape quality is poorly understood. We hypothesized that the use of CPPU in pre-flowering can lead to changes in the metabolism that affects grape quality at harvest. Therefore, we investigated the role of CPPU applications on the quality of grapes by integrating proteomics and metabolomics. CPPU-treated grapevines showed a significant increase in berry size and firmness. Proteomic analyses indicated that CPPU-treated berries accumulated enzymes associated with carbohydrate metabolism, glycolysis, and tricarboxylic acid (TCA) cycle at harvest. Metabolomic analyses showed shifts in the abundance of compounds associated with carbohydrate metabolism and TCA cycle in CPPU-treated grapes. These findings suggest that CPPU applications modulate central carbon metabolism, improving grape berry quality. [ABSTRACT FROM AUTHOR]

[Display omitted] • Simulated transport vibration accelerated the quality deterioration of table grapes during storage. • Vibration stress changed the morphology and chemical profile of cuticular wax in table grapes. • SO 2 treatment ameliorated vibration stress-induced losses in the postharvest quality of table grapes. • SO 2 treatment increased triterpenoid wax abundance by regulating related genes expression. The cuticular wax layer as a natural defensive barrier plays a key role in postharvest fruit quality maintenance. This study investigated the effects of simulated transport vibration (STV) on the berry quality and cuticular wax, and the ability of sulfur dioxide (SO 2) to ameliorate STV damage in table grapes during cold storage. Results showed that STV damage accelerated the deterioration in grapes quality, and resulted in degradation and melting of cuticular wax, accompanied by a decrease in load of total wax, triterpenoids, fatty acids, alcohols, and olefins while an increase in alkanes and esters content during subsequent storage. However, SO 2 effectively reversed the adverse impact of STV damage by increasing most wax fraction levels and corresponding genes expression, especially triterpenoids, although it had no apparent effect on wax structure. Overall, SO 2 delayed the quality deterioration caused by vibration damage that occurs during transportation and storage by altering cuticular wax composition. [ABSTRACT FROM AUTHOR]

[Display omitted] • Methoxypyrazines are not present in Shiraz grape but are in bunch stem (rachis) • Rootstock can influence methoxypyrazine (MP) concentrations in the rachis of Shiraz. • Vine vigour associated with rootstock had positive correlations with MPs in rachis. • Exclusion of sunlight from bunches increased MP concentrations in rachis. • Terroir (related to climate, soil, vine management) also influences MPs in rachis. Vitis vinifera L. cv Shiraz appears unable to synthesise 3-alkyl-2-methoxypyrazines (MPs) in the berry, but can still produce significant concentrations in rachis. MPs are readily extracted from rachis during fermentation, producing Shiraz wines with uncharacteristic "green" flavours. Recently, rootstocks were shown to significantly alter MP concentrations in Cabernet Sauvignon rachis compared to own-rooted varieties, but whether Shiraz followed a similar trend required investigation. This study considered the effect of thirteen rootstocks on the concentrations of 3-isobutyl-2-methoxypyrazine (IBMP), 3-isopropyl-2-methoxypyrazine (IPMP), and 3- sec -butyl-2-methoxypyrazine (SBMP) in the rachis of Shiraz bunches sampled during multiple vintages across several Australian growing regions. Although IBMP was the most abundant, all measured MP concentrations were significantly affected by vintage, rootstock, and region. In addition, vine vigour showed positive correlations with IBMP, which were attributed to changes in canopy coverage impacting rachis light exposure. This hypothesis was explored with light exclusion trials, which significantly increased rachis IBMP concentrations. [ABSTRACT FROM AUTHOR]

Corinthian currant simple sugar profile was determined by high-pressure liquid chromatography coupled with refractive index detection; the content in other macroconstituents was also assessed. Corinthian currants analyzed were obtained over three consecutive crop years, while the effect of cultivation area altitude was also evaluated. Sugar extraction was optimized with respect to solvent, process, and time. Simple sugar chromatographic analysis was validated for linearity (R 2 > 0.999), limits of detection (6.23–186.66 mg/L) and quantification (18.89–565.65 mg/L), precision (%RSD < 2.67), and recovery (97.99–101.99%). Fructose, glucose, sucrose, maltose, and total sugar content was 32 ± 1%, 32.5 ± 0.6%, 0.40 ± 0.04%, 0.72 ± 0.07% and 66 ± 2%, respectively; moisture, ash, fat, and protein content was 13.8 ± 0.5%, 2.6 ± 0.7%, 0.43 ± 0.06%, and 2.2 ± 0.4%, respectively. Relatively small variations in sugar and other macroconstituent content were detected over the consecutive crops. Cultivation area altitude affected Corinthian currant sugar, fat, and protein content, yet with no remarkable differences. [ABSTRACT FROM AUTHOR]

Previous studies have shown that volatile compounds present within a vineyard during the growing season can be absorbed by grapevines, assimilated within grapes, and then released during fermentation to influence the final aroma of wine. For example, the accumulation of volatile phenols in glycoconjugate forms following grapevine exposure to bushfire smoke, and their subsequent release during winemaking. This study investigated the accumulation of guaiacol glycoconjugates in the fruit, shoots and leaves of Monastrell grapevines following foliar applications (at veraison) of either an aqueous solution of guaiacol or an aqueous oak extract. Fruit, shoot and leaf samples were then collected at 3 time points between veraison and maturity, and analysed by gas chromatography-mass spectrometry and liquid chromatography–tandem mass spectrometry, to quantify guaiacol and its glycoconjugates, respectively. Guaiacol glycoconjugates were observed in fruit and leaves in particular, demonstrating glycosylation occurred after grapevine treatment; however, different glycoconjugate profiles were apparent. [ABSTRACT FROM AUTHOR]

The study evaluated fruit quality parameters and chemical properties (soluble solids, pH, total acidity and total sugars content, phenolic compounds and antioxidant activity (ABTS, FRAP and ORAC methods)) of 30 grape cultivars of white, red and pink grape, as 28 interspecific hybrids and 2 Vitis vinifera L. popularly grown in Poland. Some of them were analyzed for the first time. A total of 49 polyphenolic compounds were identified by LC-PDA-QTOF/MS and quantified by UPLC-PDA-FL, as 26 anthocyanins, 9 flavonols and flavons, 7 phenolic acids, 6 flavan-3-ols, and 1 stilbene. The content of total polyphenols ranged from 1037.0 (Cascade cv.) to 5759.1 mg/100 g dm (Roesler cv.). However, the content of stilbene represented by trans resveratrol-3-glucoside was only 18.5–70.5 mg/100 g dm. Red grape cultivars like Roesler, Rothay and Swenson Red were characterized by the highest content of bioactive compounds and antioxidant activity (significantly more than 24, 12 and 53 mmol TE/100 g dm, by ABTS, FRAP and ORAC, respectively). Average total acidity and soluble solids for white (0.95 g of tartaric acid in 100 g fm and 17.1°Bx, respectively) and for red and pink (0.93 g of tartaric acid in 100 g fm and 17.4°Bx, respectively) cultivars were not significantly different (p > 0.05). [ABSTRACT FROM AUTHOR]

[Display omitted] • Quercetin and catechin have excellent nutritional as well as therapeutic value. • Kaempferol and resveratrol have shown excellent anti-proliferative activities via P13K/Akt and MAPK blockage. • The anti-proliferative mechanism also involved reduction in levels of NRF2 and NFκB. • Cardio protection involved low oxidation of LDL and HDL proteins. • Grape polyphenols inhibit α-glucosidase to control diabetes. The intake of herbal dietary constituents, mostly fruits and vegetables, have been considered well-known to prevent pathologies (degenerative diseases). Consumer awareness/concern regarding a balanced diet has increased their importance in the food chain. Grapes (Vitis vinifera L.), being native to the Mediterranean region, central Europe, and southwest Asia, is a rich source of nutritive (sugar, vitamins, minerals) and non-nutritive/therapeutic or functional bioactive compounds like quercetin, resveratrol and epigallocatechin-3-gallate that could synergistically help in health promotion. Their disease prevention mechanisms are free radical scavenging, DNA damage repair, and modulation of gene expression in proliferation, metabolism, cell survival, and antioxidant defense. This review provides an excellent summary of grape phytochemicals in vivo molecular mechanisms that lead to health promotion by avoiding oxidative stress-related pathologies like cancer, neurodegeneration, metabolic syndrome, inflammation and cardiovascular diseases. Grape intake-driven disease-preventing mechanism/targets could help to synchronize for an improved efficacy in human pathologies. [ABSTRACT FROM AUTHOR]

The increasing demand for natural foods and beverages, i.e. prepared by excluding synthetic chemicals along the whole production chain, has boosted the adoption of organic and biodynamic cultivation methods which are based on protocols avoiding use of synthetic pesticides. This trend is striking in viticulture, since wine production is largely shaped by the varying drinking attitudes of environment-friendly consumers. Using 1 H NMR, the compositions of grape berries, collected at harvest in 2009 and 2011, in experimental plots cultivated either with biodynamic or organic methods, were compared. Although the analysis provides a comprehensive metabolic profile of berries, the resulting distinctive pattern consists of a few molecules. Lower content of sugars, coumaric and caffeic acids, as well as higher amount of γ-aminobutyric acid (GABA) were observed in biodynamic grapes. The 1 H NMR foodomics approach evidenced a diverse fruit metabolome that could be associated to a different physiological response of plants to the agronomic environment. [ABSTRACT FROM AUTHOR]

Extracts of açaí seed and of grape rachis alone or in combination with α-tocopherol were evaluated as antioxidants in (i) bulk soybean oil, (ii) soybean oil liposomes and (iii) soybean-oil/water emulsions. The extracts made with 57% aqueous ethanol showed an antioxidant activity not dependent on concentration for grape rachis extracts and a concentration-dependent prooxidative activity for açaí seed extracts in bulk soybean oil. Both the extracts, however, protected liposome suspensions and oil/water emulsions against lipid oxidation. Synergism was demonstrated when extracts were combined with α-tocopherol, effects explained by the solubility of extract components in the water-phase and of α-tocopherol in the lipid-phase. Phenolic profiling of the extracts by U-HPLC-ESI-LTQ-MS was used to identify active antioxidants. Açaí seed and grape rachis extracts served as good sources of procyanidins and flavan-3-ols, imparted high antioxidant activity especially when combined with α-tocopherol and are suggested for protection of food oil/water emulsions. [ABSTRACT FROM AUTHOR]

The influence exerted by bunch microclimate on some C 13 -norisoprenoid precursors content was investigated for the first time in Nebbiolo grapes during ripening. Samples were collected, during two consecutive seasons, from two vineyards, which are characterized by different microclimatic conditions caused by vine vigour heterogeneity and different vineyard aspects. Enzymatic hydrolysis of the glycosides extracted from the grapes, and subsequent GC–MS determination of the aglycones, highlighted that the majority of norisoprenoid glycosides accumulated in Nebbiolo berries from pre-veraison until 3–4 weeks post-veraison. Vineyard aspect and vine vigour affected the timing of the maximum concentration of norisoprenoid precursors and their subsequent decrease at harvest. Low light in the vigorous blocks penalized norisoprenoids peak concentration. In the south less vigorous blocks, a decline of total norisoprenoids content during the pre-harvest period was observed. This decline appeared mainly regulated by the temperature. Vintage and/or microclimatic conditions affected the final content of some important norisoprenoids. [ABSTRACT FROM AUTHOR]

The evolution of phenolic compounds and their relationship with the antioxidant capacity (AC) of samples taken along the winemaking process of three Vitis vinifera L. cv., Syrah, Merlot and Cabernet Sauvignon grown in Argentina were studied. Forty-five compounds were identified by HPLC-PDA-MS/MS, while the AC was determined by FRAP, ABTS and DPPH assays. Results show that phenolic composition and AC vary along the winemaking process and between varieties. Multiple regression analysis showed a high correlation between phenolic composition and AC of samples, being anthocyanins the main family with significant contribution to AC. In addition, quantitative differences in specific phenolic compounds help to explain differences in AC observed between varieties. A high phenolic content and bioactivity still remain in pomaces which support its use as an inexpensive source of antioxidants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Viniferins were isolated from vine stalks using a combination of CPC and Prep. HPLC. • The enantiomers of E-ε- viniferins and E-ω- viniferins were purified by chiral HPLC. • NMR and VCD associated to DFT calculations establish the (7aS,8aS) and (7a R ,8a S) configurations for E - ε - and E - ω -viniferin. • Cabernet Sauvignon grape variety provides the quasi enantiopure (+)-(7a S ,8a S)- E-ε -viniferin compound. • (+)-(7a S ,8a S)- E-ε- viniferin was the most efficient compound diminishing NO and ROS. Determination of stereochemistry and enantiomeric excess in chiral natural molecules is a research of great interest because enantiomers can exhibit different biological activities. Viniferin stilbene dimers are natural molecules present in grape berries and wine but also, in larger amount, in stalks of grapevine. Four stereoisomers of viniferin stilbene dimers (7a S ,8a S) -E-ε- viniferin (1a), (7a R ,8a R) -E-ε- viniferin (1b), (7a S ,8a R) -E-ω- viniferin (2a), and (7a R ,8a S) -E-ω- viniferin (2b) were isolated from grapevine stalks of Cabernet Sauvignon, Merlot and Sauvignon Blanc, using a combination of centrifugal partition chromatography (CPC), preparative and chiral HPLC. The structure elucidation of these molecules was achieved by NMR whereas the absolute configurations of the four stereoisomers were investigated by vibrational circular dichroism spectroscopy in combination with density functional theory (DFT) calculations. This study unambiguously established the (+) - (7a S, 8a S) and (+) - (7a R, 8a S) configurations for E-ε- viniferin and E-ω- viniferin, respectively. Finally, we show that Cabernet Sauvignon provided the quasi enantiopure (+) - (7a S ,8a S) -E-ε- viniferin compound which presents the best anti-inflammatory and anti-oxidant activities. [ABSTRACT FROM AUTHOR]

The flavour of wine is derived, in part, from the flavour compounds present in the grape, which change as the grapes accumulate sugar and ripen. Grape berry terpene concentrations may vary at different stages of berry development. This study aimed to investigate terpene evolution in grape berries from four weeks post-flowering to maturity. Grape bunches were sampled at fortnightly intervals over two vintages (2012–13 and 2013–14). In total, five monoterpenoids, 24 sesquiterpenes, and four norisoprenoids were detected in grape samples. The highest concentrations of total monoterpenoids, total sesquiterpenes, and total norisoprenoids in grapes were all observed at pre-veraison. Terpenes derived from the same biosynthetic pathway had a similar production pattern during berry development. Terpenes in grapes at harvest might not necessarily be synthesised at post-veraison, since the compounds or their precursors may already exist in grapes at pre-veraison, with the veraison to harvest period functioning to convert these precursors into final products. [ABSTRACT FROM AUTHOR]

In this work, the effect of water availability on astringency of seed and skin extracts of Vitis vinifera cv. Syrah berries under the typical semiarid conditions of Greece was investigated. Moreover, astringency was assessed in relation to proanthocyanidin composition. For this purpose, three irrigation treatments were applied starting at berry set through harvest of 2011 and 2012: full irrigation (FI) at 100% of crop evapotranspiration, deficit irrigation (DI) at 50% and non-irrigated (NI). FI skin and seed extracts were perceived significantly more astringent than NI. Total phenol, total tannin, (+)-catechin, (−)-epicatechin and procyanidin C1 concentrations were positively correlated with astringency. Positive correlations were also obtained among astringency and average degree of polymerization and proportion of the extension units of shorter tannins while astringency of larger tannins was correlated with the proportion of terminal units. On the contrary, total anthocyanin and epigallocatechin contents were negatively correlated with astringency. [ABSTRACT FROM AUTHOR]

The red grape Vitis vinífera is an important source of phenolic compounds, which can prevent disease if included as a part of a diet. The levels of these compounds in grapes have been associated with various environmental factors, such as climate, soil composition, and biotic stress. The purpose of this study was to determine the relationship between the elemental compositions of the soil and the grapes and the presence of bioactive compounds, such as catechin, epicatechin, piceid and resveratrol. Ethanol-based extracts of red grapes were used to quantify total and individual phenolic compounds by HPLC. It was observed that the elemental compositions of the soil and the grapes were related to their locations within different wine-producing regions. A principal component analysis showed a relationship between high metal content (Sr, Mn, Si and Pb) and higher concentrations of antioxidants in the grapes. [ABSTRACT FROM AUTHOR]

Two main precursors ( S -3-(hexan-1-ol)- l -cysteine and S -3-(hexan-1-ol)- l -glutathione) of 3-sulfanylhexanol (3SH, formerly named 3-mercaptohexanol) have been identified so far in grape juice but a correlation between precursor concentrations in grape juices and 3SH concentrations in wines is not always observed. This suggests that there may be other compounds associated with the aromatic potential. In this work, S -3-(hexanal)-glutathione (Glut-3SH-Al) and its bisulfite (Glut-3SH-SO 3 ) adduct were identified in Sauvignon blanc grape juice by liquid chromatography coupled to Fourier transform mass spectrometry experiments. A partial purification of the compounds was carried out by Medium Pressure Liquid Chromatography (MPLC) on the reverse phase using 5 L of grape juice. The addition of synthetized Glut-3SH-Al and Glut-3SH-SO 3 in the synthetic medium induced a significant release of 3SH after fermentation. Moreover, we demonstrate that Glut-3SH-Al and its bisulfite adduct are present in grape juice and could be considered as new direct 3SH precursors with molar conversion yields close to 0.4%. [ABSTRACT FROM AUTHOR]

A germplasm set of twenty-five grapevine accessions, forming eleven groups of possible berry skin color mutants, were genotyped with twelve microsatellite loci, being eleven of them identified as true color mutants. The polyphenolic profiling of the confirmed mutant cultivars revealed a total of twenty-four polyphenols, comprising non-colored compounds (phenolic acids, flavan-3-ols, flavonols and a stilbene) and anthocyanins. Results showed differences in the contribution of malvidin-3- O -glucoside to the characteristic Pinot Noir anthocyanins profile. Regarding the two Pique-Poul colored variants, the lighter variant was richer than the darker one in all classes of compounds, excepting anthocyanins. In Moscatel Galego Roxo the F3′H pathway seems to be more active than F3′5′H, resulting in higher amounts of cyanidin, precursor of the cyanidin derivatives. As far as we are aware, this is the first time that a relationship between the content of polyphenolic compounds is established in groups of grape berry skin color mutant cultivars. [ABSTRACT FROM AUTHOR]

Developmental changes in the carotenoids and volatile compounds of Pinot noir grape berries were investigated in this study from pea size to harvest during 2012. HPLC analysis showed continued decrease of lutein, β-carotene, neochrome a and neoxanthin continued to decrease during berry development, with rapid decrease of lutein and (9′z)-neoxanthin occurred two weeks before véraison . Neochrome b and violaxanthin accumulated at early development and started to decrease two weeks before véraison . Volatile analysis demonstrated that total β-damascenone, TDN and vitispirane all increased dramatically, especially at later stage of ripening, whereas the changes for α-ionone and β-ionone were not obvious. The correlation between carotenoids and C 13 -norisoprenoids in the grape berries was compound-dependent, suggesting dependency on enzyme activity and specificity. In addition, C 6 -alcohols accumulated before véraison and decreased towards maturation, and 3-isobutyl-2-methoxyprazine decreased with increasing maturity. [ABSTRACT FROM AUTHOR]

• Hard and soft phenotypes showed differential firmness between the inner and the outer mesocarp tissues. • Cell wall analysis indicated changes in galacturonic acid content in both phenotypes. • A differential carbohydrate metabolism was detected between mesocarp tissues. Tissue texture influences the grape berry consumers acceptance. We studied the biological differences between the inner and outer mesocarp tissues in hard and soft berries of table grapes cv NN107. Texture analysis revealed lower levels of firmness in the inner mesocarp as compared with the outer tissue. HPAEC-PAD analysis showed an increased abundance of cell wall monosaccharides in the inner mesocarp of harder berries at harvest. Immunohistochemical analysis displayed differences in homogalacturonan methylesterification and cell wall calcium between soft and hard berries. This last finding correlated with a differential abundance of calcium measured in the alcohol-insoluble residues (AIR) of the inner tissue of the hard berries. Analysis of abundance of polar metabolites suggested changes in cell wall carbon supply precursors, providing new clues in the identification of the biochemical factors that define the texture of the mesocarp of grape berries. [ABSTRACT FROM AUTHOR]