Efecto de la técnica de sangrado sobre la composición fenólica de vinos cv. Malbec = Effect of saignée on phenolic composition of Malbec wines

El mercado actual exige, en gran parte, la disponibilidad de vinos estructurados con coloraciones intensas, razón por la cual los enólogos evalúan constantemente diversas variantes tecnológicas tendientes a satisfacer los requerimientos del consumidor. En respuesta a esta necesidad, se estudió la incidencia de la técnica de sangrado (T1, 10%; T2, 20%; T3, 30%) sobre la composición fenólica de vinos cv. Malbec de Mendoza en dos vendimias consecutivas. En 2010 se observó que solo T3 aumentó significativamente el contenido de antocianos en los vinos terminados respecto del control, sin apreciarse un efecto sobre el resto de los parámetros fenólicos evaluados. En cuanto a los compuestos individuales determinados por HPLC- DAD/ESI-MS, los tres tratamientos favorecieron la extracción de los distintos derivados antociánicos y flavonoles, siendo T3 el más significativo. En 2011 se observó una tendencia similar además de un efecto significativo en la intensidad colorante, fenoles totales, proantocianidinas, ácidos hidroxibenzoicos, flavanoles, flavonoles y dihidroflavonoles. Por el contrario, el test triangular mostró la imposibilidad de diferenciar los vinos estudiados a través de un panel entrenado de jueces. Al comparar ambas temporadas, se pudo evidenciar la influencia del factor "año" sobre la composición de los vinos elaborados con y sin aplicación del sangrado. En conclusión, esta práctica enológica puede ser una herramienta útil para aumentar la calidad polifenólica del Malbec y mejorar la capacidad de envejecimiento en la producción de vinos de guarda.The current market, in large part, demands the availability of structured wines with intense coloration, reason why winemakers constantly evaluated different technological variants designed to satisfy the requirements of the consumer. In response to this need, the incidence of saignée (T1, 10%; T2, 20%; T3, 30%) on phenolic composition of Malbec wines from Mendoza in two consecutive seasons was studied. In 2010, it was observed that only T3 significantly increased the content of anthocyanins in wines with respect to the control, without appreciating a significant effect on the rest of the phenolic parameters evaluated. As for those individual compounds determined by HPLC-DAD/ESI-MS, the three treatments favored the extraction of different anthocyanic derivatives and flavonols, being T3 the most significant. In 2011, there was a similar trend in addition to a significant effect on the colour intensity, total phenols, proanthocyanidins, hydroxybenzoic acids, flavanols, flavonols and dihidroflavonoles. In contrast, the triangular test showed the impossibility of differentiating wines studied by a trained panel of judges. Comparing both seasons was demonstrated the influence of the "year" factor on the composition of wines made with and without application of saignée. In conclusion, this oenological practice may be a useful tool to increase the phenolic quality of Malbec wines and improve their aging potential.EEA MendozaFil: Fanzone, Martín Leandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; ArgentinaFil: Assof, Mariela Vanesa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; ArgentinaFil: Peña Neira, Alvaro. Universidad de Chile. Facultad de Ciencias Agronómicas. Departamento de Agroindustria y Enología; ChileFil: Zamora, Fernando. Universidad Rovira i Virgili. Facultad de Enología de Tarragona. Departamento de Bioquímica y Biotecnología; EspañaFil: Jofre, Viviana Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; Argentin

Micro-oxigenación de vino Carménère post fermentación maloláctica, y su influencia sobre los compuestos fenólicos, polisacáridos y pirazinas.

51 p.Micro-oxigenación (MOX) es una técnica de vinificación utilizada con el objetivo de mejorar ciertas características químicas y sensoriales del vino. Teóricamente, mediante la infusión de pequeños volúmenes de oxígeno de manera continua, la calidad del producto puede mejorar, y los peligros de la acumulación de oxígeno y la oxidación incontrolada se evitan. Sin embargo, no se han reportado los efectos producidos por la interrupción de la exposición al aire, a tasas comparables a la MOX. Por lo tanto, el objetivo de este ensayo fue evaluar los efectos químicos de un protocolo de oxigenación alternativo, basado en aires semanales de vino, en comparación con el MOX convencional (fermentación post-maloláctica). Para la mayoría de las variables analizadas, el tratamiento de aireación periódica produjo efectos equivalentes a los MOX convencionales (por ejemplo, una reducción en la concentración de antocianinas, la reducción de astringencia y la disminución del carácter herbáceo). Palabras clave: Vino, oxígeno, antocianina, pirazina, fenol, aire, polisacaridos/ABSTRACT: Micro-oxygenation (MOX) is a winemaking technique used with the aim of enhancing certain chemical and sensory wine features. Theoretically, by infusing small volumes of oxygen in a continuous way, the quality of the product may improve, and the hazards of oxygen build-up and uncontrolled oxidation are avoided. However, the effects produced by discontinued air exposure, at rates comparable to MOX, have not been reported. Therefore, the aim of this trial was to evaluate the chemical effects of an alternative oxygenation protocol, based on weekly wine aerations, compared to conventional MOX (post-malolactic fermentation). For most of the variables analyzed, the periodic aeration treatment produced equivalent effects as conventional MOX (e.g. a reduction in the concentration anthocyanins, the reduction of astringency, and the decrease of the herbaceous character). Key words: Wine, oxygen, anthocyanin, pyrazine, phenol, air, polysaccharide

Post-veraison sunlight exposure induces MYB-mediated transcriptional regulation of anthocyanin and flavonol synthesis in berry skins of Vitis vinifera

Anthocyanins, flavan-3-ols, and flavonols are the three major classes of flavonoid compounds found in grape berry tissues. Several viticultural practices increase flavonoid content in the fruit, but the underlying genetic mechanisms responsible for these changes have not been completely deciphered. The impact of post-veraison sunlight exposure on anthocyanin and flavonol accumulation in grape berry skin and its relation to the expression of different transcriptional regulators known to be involved in flavonoid synthesis was studied. Treatments consisting of removing or moving aside the basal leaves which shade berry clusters were applied. Shading did not affect sugar accumulation or gene expression of HEXOSE TRANSPORTER 1, although in the leaf removal treatment, these events were retarded during the first weeks of ripening. Flavonols were the most drastically reduced flavonoids following shading and leaf removal treatments, related to the reduced expression of FLAVONOL SYNTHASE 4 and its putative transcriptional regulator MYB12. Anthocyanin accumulation and the expression of CHS2, LDOX, OMT, UFGT, MYBA1, and MYB5a genes were also affected. Other regulatory genes were less affected or not affected at all by these treatments. Non-transcriptional control mechanisms for flavonoid synthesis are also suggested, especially during the initial stages of ripening. Although berries from the leaf removal treatment received more light than shaded fruits, malvidin-3-glucoside and total flavonol content was reduced compared with the treatment without leaf removal. This work reveals that flavonol-related gene expression responds rapidly to field changes in light levels, as shown by the treatment in which shaded fruits were exposed to light in the late stages of ripening. Taken together, this study establishes MYB-specific responsiveness for the effect of sun exposure and sugar transport on flavonoid synthesis

The photomorphogenic factors UV-B RECEPTOR 1, ELONGATED HYPOCOTYL 5, and HY5 HOMOLOGUE are part of the UV-B signalling pathway in grapevine and mediate flavonol accumulation in response to the environment

Grapevine (Vitis vinifera L.) is a species well known for its adaptation to radiation. However, photomorphogenic factors related to UV-B responses have not been molecularly characterized. We cloned and studied the role of UV-B RECEPTOR (UVR1), ELONGATED HYPOCOTYL 5 (HY5), and HY5 HOMOLOGUE (HYH) from V. vinifera. We performed gene functional characterizations, generated co-expression networks, and tested them in different environmental conditions. These genes complemented the Arabidopsis uvr8 and hy5 mutants in morphological and secondary metabolic responses to radiation. We combined microarray and RNA sequencing (RNA-seq) data with promoter inspections to identify HY5 and HYH putative target genes and their DNA binding preferences. Despite sharing a large set of common co-expressed genes, we found different hierarchies for HY5 and HYH depending on the organ and stress condition, reflecting both co-operative and partially redundant roles. New candidate UV-B gene markers were supported by the presence of HY5-binding sites. These included a set of flavonol-related genes that were up-regulated in a HY5 transient expression assay. We irradiated in vitro plantlets and fruits from old potted vines with high and low UV-B exposures and followed the accumulation of flavonols and changes in gene expression in comparison with non-irradiated conditions. UVR1, HY5, and HYH expression varied with organ, developmental stage, and type of radiation. Surprisingly, UVR1 expression was modulated by shading and temperature in berries, but not by UV-B radiation. We propose that the UV-B response machinery favours berry flavonol accumulation through the activation of HY5 and HYH at different developmental stages at both high and low UV-B exposures. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology

A crowdsourcing database for the copy-number variation of the Spanish population

Background: Despite being a very common type of genetic variation, the distribution of copy-number variations (CNVs) in the population is still poorly understood. The knowledge of the genetic variability, especially at the level of the local population, is a critical factor for distinguishing pathogenic from non-pathogenic variation in the discovery of new disease variants. Results: Here, we present the SPAnish Copy Number Alterations Collaborative Server (SPACNACS), which currently contains copy number variation profiles obtained from more than 400 genomes and exomes of unrelated Spanish individuals. By means of a collaborative crowdsourcing effort whole genome and whole exome sequencing data, produced by local genomic projects and for other purposes, is continuously collected. Once checked both, the Spanish ancestry and the lack of kinship with other individuals in the SPACNACS, the CNVs are inferred for these sequences and they are used to populate the database. A web interface allows querying the database with different filters that include ICD10 upper categories. This allows discarding samples from the disease under study and obtaining pseudo-control CNV profiles from the local population. We also show here additional studies on the local impact of CNVs in some phenotypes and on pharmacogenomic variants. SPACNACS can be accessed at: http://csvs.clinbioinfosspa.es/spacnacs/. Conclusion: SPACNACS facilitates disease gene discovery by providing detailed information of the local variability of the population and exemplifies how to reuse genomic data produced for other purposes to build a local reference database

First Latin American clinical practice guidelines for the treatment of systemic lupus erythematosus: Latin American Group for the Study of Lupus (GLADEL, Grupo Latino Americano de Estudio del Lupus)-Pan-American League of Associations of Rheumatology (PANLAR)

Systemic lupus erythematosus (SLE), a complex and heterogeneous autoimmune disease, represents a significant challenge for both diagnosis and treatment. Patients with SLE in Latin America face special problems that should be considered when therapeutic guidelines are developed. The objective of the study is to develop clinical practice guidelines for Latin American patients with lupus. Two independent teams (rheumatologists with experience in lupus management and methodologists) had an initial meeting in Panama City, Panama, in April 2016. They selected a list of questions for the clinical problems most commonly seen in Latin American patients with SLE. These were addressed with the best available evidence and summarised in a standardised format following the Grading of Recommendations Assessment, Development and Evaluation approach. All preliminary findings were discussed in a second face-to-face meeting in Washington, DC, in November 2016. As a result, nine organ/system sections are presented with the main findings; an 'overarching' treatment approach was added. Special emphasis was made on regional implementation issues. Best pharmacologic options were examined for musculoskeletal, mucocutaneous, kidney, cardiac, pulmonary, neuropsychiatric, haematological manifestations and the antiphospholipid syndrome. The roles of main therapeutic options (ie, glucocorticoids, antimalarials, immunosuppressant agents, therapeutic plasma exchange, belimumab, rituximab, abatacept, low-dose aspirin and anticoagulants) were summarised in each section. In all cases, benefits and harms, certainty of the evidence, values and preferences, feasibility, acceptability and equity issues were considered to produce a recommendation with special focus on ethnic and socioeconomic aspects. Guidelines for Latin American patients with lupus have been developed and could be used in similar settings.Fil: Pons Estel, Bernardo A.. Centro Regional de Enfermedades Autoinmunes y Reumáticas; ArgentinaFil: Bonfa, Eloisa. Universidade de Sao Paulo; BrasilFil: Soriano, Enrique R.. Instituto Universitario Hospital Italiano de Buenos Aires. Rectorado.; ArgentinaFil: Cardiel, Mario H.. Centro de Investigación Clínica de Morelia; MéxicoFil: Izcovich, Ariel. Hospital Alemán; ArgentinaFil: Popoff, Federico. Hospital Aleman; ArgentinaFil: Criniti, Juan M.. Hospital Alemán; ArgentinaFil: Vásquez, Gloria. Universidad de Antioquia; ColombiaFil: Massardo, Loreto. Universidad San Sebastián; ChileFil: Duarte, Margarita. Hospital de Clínicas; ParaguayFil: Barile Fabris, Leonor A.. Hospital Angeles del Pedregal; MéxicoFil: García, Mercedes A.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Amigo, Mary Carmen. Centro Médico Abc; MéxicoFil: Espada, Graciela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Catoggio, Luis J.. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: Sato, Emilia Inoue. Universidade Federal de Sao Paulo; BrasilFil: Levy, Roger A.. Universidade do Estado de Rio do Janeiro; BrasilFil: Acevedo Vásquez, Eduardo M.. Universidad Nacional Mayor de San Marcos; PerúFil: Chacón Díaz, Rosa. Policlínica Méndez Gimón; VenezuelaFil: Galarza Maldonado, Claudio M.. Corporación Médica Monte Sinaí; EcuadorFil: Iglesias Gamarra, Antonio J.. Universidad Nacional de Colombia; ColombiaFil: Molina, José Fernando. Centro Integral de Reumatología; ColombiaFil: Neira, Oscar. Universidad de Chile; ChileFil: Silva, Clóvis A.. Universidade de Sao Paulo; BrasilFil: Vargas Peña, Andrea. Hospital Pasteur Montevideo; UruguayFil: Gómez Puerta, José A.. Hospital Clinic Barcelona; EspañaFil: Scolnik, Marina. Instituto Universitario Hospital Italiano de Buenos Aires. Rectorado.; ArgentinaFil: Pons Estel, Guillermo J.. Centro Regional de Enfermedades Autoinmunes y Reumáticas; Argentina. Hospital Provincial de Rosario; ArgentinaFil: Ugolini Lopes, Michelle R.. Universidade de Sao Paulo; BrasilFil: Savio, Verónica. Instituto Universitario Hospital Italiano de Buenos Aires. Rectorado.; ArgentinaFil: Drenkard, Cristina. University of Emory; Estados UnidosFil: Alvarellos, Alejandro J.. Hospital Privado Universitario de Córdoba; ArgentinaFil: Ugarte Gil, Manuel F.. Universidad Cientifica del Sur; Perú. Hospital Nacional Guillermo Almenara Irigoyen; PerúFil: Babini, Alejandra. Instituto Universitario Hospital Italiano de Buenos Aires. Rectorado.; ArgentinaFil: Cavalcanti, André. Universidade Federal de Pernambuco; BrasilFil: Cardoso Linhares, Fernanda Athayde. Hospital Pasteur Montevideo; UruguayFil: Haye Salinas, Maria Jezabel. Hospital Privado Universitario de Córdoba; ArgentinaFil: Fuentes Silva, Yurilis J.. Universidad de Oriente - Núcleo Bolívar; VenezuelaFil: Montandon De Oliveira E Silva, Ana Carolina. Universidade Federal de Goiás; BrasilFil: Eraso Garnica, Ruth M.. Universidad de Antioquia; ColombiaFil: Herrera Uribe, Sebastián. Hospital General de Medellin Luz Castro de Gutiérrez; ColombiaFil: Gómez Martín, DIana. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Robaina Sevrini, Ricardo. Universidad de la República; UruguayFil: Quintana, Rosana M.. Hospital Provincial de Rosario; Argentina. Centro Regional de Enfermedades Autoinmunes y Reumáticas; ArgentinaFil: Gordon, Sergio. Hospital Interzonal General de Agudos Dr Oscar Alende. Unidad de Reumatología y Enfermedades Autoinmunes Sistémicas; ArgentinaFil: Fragoso Loyo, Hilda. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Rosario, Violeta. Hospital Docente Padre Billini; República DominicanaFil: Saurit, Verónica. Hospital Privado Universitario de Córdoba; ArgentinaFil: Appenzeller, Simone. Universidade Estadual de Campinas; BrasilFil: Dos Reis Neto, Edgard Torres. Universidade Federal de Sao Paulo; BrasilFil: Cieza, Jorge. Hospital Nacional Edgardo Rebagliati Martins; PerúFil: González Naranjo, Luis A.. Universidad de Antioquia; ColombiaFil: González Bello, Yelitza C.. Ceibac; MéxicoFil: Collado, María Victoria. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Sarano, Judith. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Retamozo, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Sattler, María E.. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Gamboa Cárdenas, Rocio V.. Hospital Nacional Guillermo Almenara Irigoyen; PerúFil: Cairoli, Ernesto. Universidad de la República; UruguayFil: Conti, Silvana M.. Hospital Provincial de Rosario; ArgentinaFil: Amezcua Guerra, Luis M.. Instituto Nacional de Cardiologia Ignacio Chavez; MéxicoFil: Silveira, Luis H.. Instituto Nacional de Cardiologia Ignacio Chavez; MéxicoFil: Borba, Eduardo F.. Universidade de Sao Paulo; BrasilFil: Pera, Mariana A.. Hospital Interzonal General de Agudos General San Martín; ArgentinaFil: Alba Moreyra, Paula B.. Universidad Nacional de Córdoba. Facultad de Medicina; ArgentinaFil: Arturi, Valeria. Hospital Interzonal General de Agudos General San Martín; ArgentinaFil: Berbotto, Guillermo A.. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Gerling, Cristian. Hospital Interzonal General de Agudos Dr Oscar Alende. Unidad de Reumatología y Enfermedades Autoinmunes Sistémicas; ArgentinaFil: Gobbi, Carla Andrea. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gervasoni, Viviana L.. Hospital Provincial de Rosario; ArgentinaFil: Scherbarth, Hugo R.. Hospital Interzonal General de Agudos Dr Oscar Alende. Unidad de Reumatología y Enfermedades Autoinmunes Sistémicas; ArgentinaFil: Brenol, João C. Tavares. Hospital de Clinicas de Porto Alegre; BrasilFil: Cavalcanti, Fernando. Universidade Federal de Pernambuco; BrasilFil: Costallat, Lilian T. Lavras. Universidade Estadual de Campinas; BrasilFil: Da Silva, Nilzio A.. Universidade Federal de Goiás; BrasilFil: Monticielo, Odirlei A.. Hospital de Clinicas de Porto Alegre; BrasilFil: Seguro, Luciana Parente Costa. Universidade de Sao Paulo; BrasilFil: Xavier, Ricardo M.. Hospital de Clinicas de Porto Alegre; BrasilFil: Llanos, Carolina. Universidad Católica de Chile; ChileFil: Montúfar Guardado, Rubén A.. Instituto Salvadoreño de la Seguridad Social; El SalvadorFil: Garcia De La Torre, Ignacio. Hospital General de Occidente; MéxicoFil: Pineda, Carlos. Instituto Nacional de Rehabilitación; MéxicoFil: Portela Hernández, Margarita. Umae Hospital de Especialidades Centro Medico Nacional Siglo Xxi; MéxicoFil: Danza, Alvaro. Hospital Pasteur Montevideo; UruguayFil: Guibert Toledano, Marlene. Medical-surgical Research Center; CubaFil: Reyes, Gil Llerena. Medical-surgical Research Center; CubaFil: Acosta Colman, Maria Isabel. Hospital de Clínicas; ParaguayFil: Aquino, Alicia M.. Hospital de Clínicas; ParaguayFil: Mora Trujillo, Claudia S.. Hospital Nacional Edgardo Rebagliati Martins; PerúFil: Muñoz Louis, Roberto. Hospital Docente Padre Billini; República DominicanaFil: García Valladares, Ignacio. Centro de Estudios de Investigación Básica y Clínica; MéxicoFil: Orozco, María Celeste. Instituto de Rehabilitación Psicofísica; ArgentinaFil: Burgos, Paula I.. Pontificia Universidad Católica de Chile; ChileFil: Betancur, Graciela V.. Instituto de Rehabilitación Psicofísica; ArgentinaFil: Alarcón, Graciela S.. Universidad Peruana Cayetano Heredia; Perú. University of Alabama at Birmingahm; Estados Unido

Impact of phenolic and polysaccharidic composition on commercial value of Argentinean Malbec and Cabernet Sauvignon wines

Knowledge of the chemical composition of wine and its association with the commercial value constitutes an objective tool to assess quality and can be used as a marketing strategy. Phenolic compounds are very important quality parameters of wines because of their impact on color, taste and health properties, and together with polysaccharides contribute to the chemical stability and sensory perception of the products. In this context, the major aims of the present study were to describe the phenolic and polysaccharidic composition of Argentinean Malbec and Cabernet Sauvignon wines of different price segments, and assessing their impact on the commercial value. Thirty wines representative of three retail price segments (US$ 5–7, 18–20, and > 40) were evaluated. In general, there was a trend towards greater concentration of these compounds with increasing the commercial value of wines. Particularly, it was found that general phenolic composition, color-related compounds, main flavonoid groups and polysaccharides appear as relevant variables differing among segments and showing some differences between varieties. Additionally, the sensory wine description was in good agreement with the analytical results. The wines of greater commercial value, with the best visual and gustatory scores, coincided with higher levels of the phenolic parameters determined. This study provides an interesting insight, no reported so far, on the impact of phenolic and polysaccharidic composition in the final quality of the products and therefore in its market value.EEA MendozaFil: Fanzone, Martín Leandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; ArgentinaFil: Peña Neira, Alvaro. Universidad de Chile. Facultad de Ciencias Agronómicas. Departamento de Agroindustria y Enología; ChileFil: Gil, Mariona. Universidad Rovira i Virgili. Facultad de Enología de Tarragona. Departamento de Bioquímica y Biotecnología; EspañaFil: Jofre, Viviana Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; ArgentinaFil: Assof, Mariela Vanesa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; ArgentinaFil: Zamora, Fernando. Universidad Rovira i Virgili. Facultad de Enología de Tarragona. Departamento de Bioquímica y Biotecnología; Españ

Phenolic Characterization of Commercial Enological Tannins

Draft Manuscript for ReviewEnological tannins are widely used in winemaking process to improve different characteristics of wines. A wide spectrum of enological tannins is now available on the market; however, the tannins’ chemical nature and botanical origin are not always clearly defined in the commercial products. The aim of this work was the chemical characterization of ten commercial plant-derived tanning agents of enological use. Enological tannins were analyzed by spectrophotometry (total phenols, total tannins and gelatin index) and High Performance Liquid Chromatography (HPLC-DAD) (low molecular weight phenolic compounds). In general it was possible observe important differences in the concentration of total phenols, total tannins and gelatin index values among the commercial products studied. By using HPLC-DAD it was possible classified different types of tannins (mainly hydrolyzable (gallotannins and ellagitannins), condensed or proanthocyanidic tannins and blends of these groups). Clear differences were evident between the study results and the information on the type of tannin indicated on some of the commercial tannin labels. These discrepancies could lead to technological problems in the winery industry because of the different aims that guide the use of different types of these enological products