Caftaric acid in grapes and conversion to a reaction product during processing

Grapes were crushed in the presence of high levels of the anti-oxidants SO2 and ascorbic acid, in an atmosphere deprived of oxygen. Hydroxycinnamic derivatives, particularly caftaric acid in the grape juice were found in much higher amounts than when the usual processing methods were employed.Partial oxidation of caftaric acid is not only very rapid and extensive during unprotected grflpe crushing and juice separation but gives a major reaction product that behaves as a single entity and survives through vinification. It gives a sharp HPLC peak and behaves reciprocally with caftaric, i.e., when caftaric acid in must remains high relative to the berry content the reaction product is low and vice versa. The product appeared identical in all grape varieties tested.The reaction product is about one-sixth as extractable by immiscible solvents as is the parent caftaric acid. It can constitute a large part of the 320 nm absorbance of a wine and explains the variable results and poor yields in attempts to isolate caftaric acid from ordinary wine or juice.L'acide caftarique des raisins et sa conversion en produit de réaction au cours de la vinificationA l'aide de HPLC il a été mis en évidence que l'acide caftarique (caffeoyl tartrique) subit des pertes rapides lors du foulage des raisins dans le cas où ceux-ci ne sont pas complètement protégés contre l'oxidation, comme par ex. foulage en atmosphère inerte en présence d'un niveau élevé de métabisulfite de potassium et d'acide ascorbique. En l'absence de telles précautions les valeurs de la teneur originelle en acide caftarique, considérées comme étant caractéristiques des variétés de vigne, sont douteuses. Des échantillons totalement protégés de 5 variétés blanches et 3 variétés rouges de Vitis vinifera, mûres, se rangent entre 200 mg/l de jus pour Grenache et 50 mg/l pour Carignane. Dans la mesure que l'exposition à l'oxygène et l'activité de phénolase sont évaluables la perte peut être importante. Une majeure partie de cette perte consiste dans un produit de réaction de l'acide caftarique ici pour la première fois décelé (CRP). Ce CRP peut pénétrer dans le vin et sa détermination par HPLC ainsi que celle de l'acide caftarique non transformé montrent, en fonction de la variété de vigne, une grande conversion au cours de la préparation normale du moût. De telles analyses de vins peuvent servir d'indicateurs de l'exposition à l'oxygène au cours de la préparation du moût. La nature du CRP est actuellement étudiée et sa présence peut contribuer à expliquer la faible récupération de l'acide caftarique du moût ou du vin

Theia Snow collection: high-resolution operational snow cover maps from Sentinel-2 and Landsat-8 data

The Theia Snow collection routinely provides high-resolution maps of the snow-covered area from Sentinel-2 and Landsat-8 observations. The collection covers selected areas worldwide, including the main mountain regions in western Europe (e.g. Alps, Pyrenees) and the High Atlas in Morocco. Each product of the Theia Snow collection contains four classes: snow, no snow, cloud and no data. We present the algorithm to generate the snow products and provide an evaluation of the accuracy of Sentinel-2 snow products using in situ snow depth measurements, higher-resolution snow maps and visual control. The results suggest that the snow is accurately detected in the Theia snow collection and that the snow detection is more accurate than the Sen2Cor outputs (ESA level 2 product). An issue that should be addressed in a future release is the occurrence of false snow detection in some large clouds. The snow maps are currently produced and freely distributed on average 5&thinsp;d after the image acquisition as raster and vector files via the Theia portal (https://doi.org/10.24400/329360/F7Q52MNK).</p

Tumors escape immunosurveillance by overexpressing the proteasome activator PSME3

The success of CD8+ T cell-based cancer immunotherapy emphasizes the importance of understanding the mechanisms of generation of MHC-I peptide ligands and the possible pathways of tumor cell escape from immunosurveillance. Recently, we showed that peptides generated in the nucleus during a pioneer round of mRNA translation (pioneer translation products, or PTPs) are an important source of tumor specific peptides which correlates with the aberrant splicing and transcription events associated with oncogenesis. Here we show that up-regulation of PSME3 proteasome activator in cancer cells results in increased destruction of PTP-derived peptides in the nucleus thus enabling cancer cell to subvert immunosurveillance. These findings unveil a previously unexpected role for PSME3 in antigen processing and identify PSME3 as a druggable target to improve the efficacy of cancer immunotherapy

Microbiological and chemical monitoring of Marsala base wine obtained by spontaneous fermentation during large-scale production

The present work was undertaken to evaluate the effect of the natural winemaking on the microbial and chemical composition of Marsala base wine. To this purpose, a large-scale vinification process of Grillo grape cultivar was monitored from harvesting to the final product. Total yeasts (TY) showed a rapid increase after must pressing and reached values almost superimposable to those registered during the conventional winemakings. Lactic acid bacteria (LAB) were registered at the highest levels simultaneously to yeast growth at the beginning of the process. Saccharomyces cerevisiae was the species found at the highest concentrations in all samples analysed. Several strains (n= 16) was registered at high levels during the alcoholic fermentation and/or aging of wine; only two of them were detected on the grape surface. Lactobacillus plantarum was the LAB species most frequently isolated during the entire vinification process. Ethanol content was approximately 14% (v/v) at the end of vinification. The value of pH did not greatly vary during the process and the volatile acidity (VA) was detected at low concentrations during the entire transformation. The concentration of malic acid rapidly decreased during the AF; on the other hand, lactic acid showed an irregular trend during the entire process. trans-caffeil tartaric acid was the most abundant hydroxycinnamoyl tartaric acid and volatile organic compounds (VOC) were mainly represented by isoamylic alcohol and isobutanol

An Induced Mutation in Tomato eIF4E Leads to Immunity to Two Potyviruses

BACKGROUND: The characterization of natural recessive resistance genes and Arabidopsis virus-resistant mutants have implicated translation initiation factors of the eIF4E and eIF4G families as susceptibility factors required for virus infection and resistance function. METHODOLOGY/PRINCIPAL FINDINGS: To investigate further the role of translation initiation factors in virus resistance we set up a TILLING platform in tomato, cloned genes encoding for translation initiation factors eIF4E and eIF4G and screened for induced mutations that lead to virus resistance. A splicing mutant of the eukaryotic translation initiation factor, S.l_eIF4E1 G1485A, was identified and characterized with respect to cap binding activity and resistance spectrum. Molecular analysis of the transcript of the mutant form showed that both the second and the third exons were miss-spliced, leading to a truncated mRNA. The resulting truncated eIF4E1 protein is also impaired in cap-binding activity. The mutant line had no growth defect, likely because of functional redundancy with others eIF4E isoforms. When infected with different potyviruses, the mutant line was immune to two strains of Potato virus Y and Pepper mottle virus and susceptible to Tobacco each virus. CONCLUSIONS/SIGNIFICANCE: Mutation analysis of translation initiation factors shows that translation initiation factors of the eIF4E family are determinants of plant susceptibility to RNA viruses and viruses have adopted strategies to use different isoforms. This work also demonstrates the effectiveness of TILLING as a reverse genetics tool to improve crop species. We have also developed a complete tool that can be used for both forward and reverse genetics in tomato, for both basic science and crop improvement. By opening it to the community, we hope to fulfill the expectations of both crop breeders and scientists who are using tomato as their model of study

Etude de quelques conditions influençant la filtration des vins sur membrane

Les coûts de la filtration sur membrane en oenologie peuvent être réduits en améliorant la filtrabilité des vins et la régénération des membranes après colmatage. Le test de filtrabilité proposé par Gaillard permet d'estimer les volumes de vin filtrables au chai, de contrôler et d'optimiser la chaîne de préparation des vins. Différentes applications sont étudiées. Le test de débit en eau permet de contrôler le colmatage et la régénération des membranes. Des techniques de régénération par trempage dans des solutions détergentes sont étudiées et proposées. +++ The cost of filtering through a membrane in enology can be reduced by improving the filterability of wines and the regeneration of clogged membranes. The filterability test proposed by Gaillard helps to estimate the volume of wine that can be filtered by a winery, to control and optimise the assembly line preparation of wines. Different applications are studied. The water flowrate test allows a better control of clopping and of membrane regeneration. Regeneration technics by soaking in detergent solutions are studied and proposed

Theia Snow collection: High-resolution operational snow cover maps from Sentinel-2 and Landsat-8 data

The Theia Snow collection routinely provides high-resolution maps of the snow-covered area from Sentinel-2 and Landsat-8 observations. The collection covers selected areas worldwide, including the main mountain regions in western Europe (e.g. Alps, Pyrenees) and the High Atlas in Morocco. Each product of the Theia Snow collection contains four classes: snow, no snow, cloud and no data. We present the algorithm to generate the snow products and provide an evaluation of the accuracy of Sentinel-2 snow products using in situ snow depth measurements, higher-resolution snow maps and visual control. The results suggest that the snow is accurately detected in the Theia snow collection and that the snow detection is more accurate than the Sen2Cor outputs (ESA level 2 product). An issue that should be addressed in a future release is the occurrence of false snow detection in some large clouds

La diversification dans la filiere vitivinicole

* ref. 10 tablesNational audienceCette publication regroupe quatre documents: 1-Une etude publiee en 1980 (et mise a jour), intitulee Crise viticole et innovation: les produits nouveaux a base de raisin. 2-Le rapport de synthese d'une etude parue en 1983, sur l'approche economique des mouts de raisin concentres dans la CEE. 3-Un article de 1983, Les enjeux economiques et sociaux d'une innovation technologique dans la filiere vitivinicole, completant l'analyse precedente sur les mouts concentres; 4-Un article de 1985, faisant la synthese des innovations apparues au cours des annees recentes, dans le domaine des boissons a faible teneur en alcool. Ces etudes sont centrees sur l'analyse de l'innovation sur les produits dans le secteur des boissons alcooliques, et notamment dans le secteur viticole. Compte tenu des bouleversements intervenus depuis plus de vingt ans dans la consommation du vin, l'etude des possibilites et des limites de la diversification des produits permet d'apprecier les perspectives de mutations qu'elle peut entrainer au sein de la filiere vitivinicole. L'annonce d'un assouplissement en 1986 des contraintes reglementaires et fiscales sur les boissons uvales, rend tout a fait d'actualite ces etudes, qui montrent que les possibilites technologiques sont grandes, que les marches potentiels sont vastes, mais que le secteur viticole n'est pas le seul concerne ni qu'il compte les operateurs industriels les mieux prepares aux evolutions futures