Malnutrition risk and associated factors in hospitalized older adult patients with neurological diseases: a retrospective cohort study.

INTRODUCTION: Malnutrition risk (MR) in older adults with neurological disorders is high, but there is little evidence for validated screening tools in this group, as well as for the clinical and socioeconomic factors associated with a high MR. OBJECTIVES: To determine the association of MR using the Malnutrition Universal Screening Tool (MUST) with mortality and length of stay (LOS) in older adults with neurological diseases. Secondarily, the association of clinical, and socioeconomic factors with MR and clinical outcomes was sought. METHODS: A retrospective cohort study was carried out at a third-level neurological disease referral center in Mexico. All patients older than 60 years admitted from January 2017 to December 2018 were considered. MUST, clinical and socioeconomic factors were assessed at hospital admission. Outcomes were followed up to hospital discharge or a maximum of 6 months. RESULTS: A total of 765 patients were included, of whom 24.7% (n = 189) were at high risk. A high MR was independently associated with mortality (OR 3.09; 95% CI 1.60-5.98, p = .001) and LOS >14 days (OR 4.38; 95% CI 2.79-6.89, p = <.001). The only factors independently associated with high MR was economic dependence and unemployment. Patients with high MR and economic dependence (OR 4.0; 95% CI 1.34-11.99, p = .013) or unemployment (OR 3.43; 95% CI 1.17-10.06, p = .025) had the highest mortality. CONCLUSIONS: In hospitalized older adults with neurological diseases, high MR is independently associated with increased mortality and LOS. Economic dependence or unemployment are associated with worse clinical outcomes in patients with high MR.

Identificación y selección de Saccharomyces cerevisiae nativas para mejorar el proceso productivo del Pisco a partir de uva Quebranta

El Pisco es el destilado del Perú, elaborado a partir de mostos recientemente fermentados con uvas criollas denominadas "pisqueras". Las levaduras son los microorganismos clave en la fermentación y el uso de cepas nativas seleccionadas presenta ventajas competitivas para la tipicidad del producto, así como también para la estandarización del producto y el control microbiológico del proceso. El objetivo fue identificar y seleccionar las cepas de levaduras nativas para la producción del Pisco de uva Quebranta aisladas de procesos productivos de Pisco en el valle de Ica. Para ello, se emplearon técnicas microbiológicas y moleculares mediante el análisis de ITS1-5.8S-ITS2 PCR-RFLP para la identidad taxonómica. La evaluación de las cepas para producir Pisco consistió en el análisis fisicoquímico y organoléptico del destilado obtenido con las cepas seleccionadas. Se evaluaron 3 aislados para la producción de Pisco identificados como Saccharomyces cerevisiae: UNA SC - 25, UNA SC - 49 y UNA SC - 54, de los cuales la cepa UNA SC-49 destacó por mostrar aptitudes enológicas diferentes a las otras cepas. Este trabajo constituye el primer registro de levaduras nativas del Perú para mostos procedentes de uva Quebranta.

El Pisco stands as Peru's distilled spirit, crafted from recently fermented musts derived from native grape varieties known as "pisqueras". Yeasts serve as decisive microorganisms in the fermentation process, and the utilization of selected native strains confers competitive advantages for product typicity, standardization, and microbiological control within the production process. The aim was to identify and select native yeast strains for Quebranta grape Pisco production, isolated from Pisco production processes in the Ica Valley. Microbiological and molecular techniques were employed, utilizing ITS1-5.8S-ITS2 PCR-RFLP analysis for taxonomic identification. The assessment of yeast strains for Pisco production involved the physicochemical and organoleptic analysis of the distilled product obtained using the selected strains. Three isolates were evaluated for Pisco production, identified as Saccharomyces cerevisiae: UNA SC - 25, UNA SC - 49, and UNA SC - 54. Among these, the UNA SC-49 strain stood out due to displaying oenological characteristics distinct from the other strains. This work is the first documentation of native yeasts in Peru for musts derived from Quebranta grapes.

Current Medical Treatment for Alcohol-Associated Liver Disease.

Alcohol-associated liver disease is one of the main causes of chronic liver disease. It comprises a clinical-histologic spectrum of presentations, from steatosis, steatohepatitis, to different degrees of fibrosis, including cirrhosis and severe necroinflammatory disease, called alcohol-associated hepatitis. In this focused update, we aim to present specific therapeutic interventions and strategies for the management of alcohol-associated liver disease. Current evidence for management in all spectra of manifestations is derived from general chronic liver disease recommendations, but with a higher emphasis on abstinence and nutritional support. Abstinence should comprise the treatment of alcohol use disorder as well as withdrawal syndrome. Nutritional assessment should also consider the presence of sarcopenia and its clinical manifestation, frailty. The degree of compensation of the disease should be evaluated, and complications, actively sought. The most severe acute form of this disease is alcohol-associated hepatitis, which has high mortality and morbidity. Current treatment is based on corticosteroids that act by reducing immune activation and blocking cytotoxicity and inflammation pathways. Other aspects of treatment include preventing and treating hepatorenal syndrome as well as preventing infections although there is no clear evidence as to the benefit of probiotics and antibiotics in prophylaxis. Novel therapies for alcohol-associated hepatitis include metadoxine, interleukin-22 analogs, and interleukin-1-beta antagonists. Finally, granulocyte colony-stimulating factor, microbiota transplantation, and gut-liver axis modulation have shown promising results. We also discuss palliative care in advanced alcohol-associated liver disease.

Fungal Diversity Analysis of Grape Musts from Central Valley-Chile and Characterization of Potential New Starter Cultures.

Autochthonous microorganisms are an important source of the distinctive metabolites that influence the chemical profile of wine. However, little is known about the diversity of fungal communities associated with grape musts, even though they are the source of local yeast strains with potential capacities to become starters during fermentation. By using internal transcribed spacer (ITS) amplicon sequencing, we identified the taxonomic structure of the yeast community in unfermented and fermented musts of a typical Vitis vinifera L. var. Sauvignon blanc from the Central Valley of Chile throughout two consecutive seasons of production. Unsurprisingly, Saccharomyces represented the most abundant fungal genus in unfermented and fermented musts, mainly due to the contribution of S. uvarum (42.7%) and S. cerevisiae (80%). Unfermented musts were highly variable between seasons and showed higher values of fungal diversity than fermented musts. Since microbial physiological characterization is primarily achieved in culture, we isolated nine species belonging to six genera of fungi from the unfermented must samples. All isolates were characterized for their potential capacities to be used as new starters in wine. Remarkably, only Metschnikowia pulcherrima could co-exist with a commercial Saccharomyces cerevisiae strain under fermentative conditions, representing a feasible candidate strain for wine production.

The effect of ion-exchange resin treatment on grape must composition and fermentation kinetics.

The aim of this study was to determine the influence of ion-exchange resin treatments of white grape must for the production of sparkling base wines, on the grape must chemical composition and fermentation kinetics. The experiment included an untreated grape must with a pH of 3.2, and resin-treated musts with pH 3.14, 3.07, and 3.01. Analysis of pH, total acidity, optical density (O.D.) at 420 nm, total phenolic content, tartaric acid, ammonium-nitrogen (AN) and cations (Ca2+, Mg2+, Cu2+, K+, and Na+) was performed. The fermentations were monitored by mass reduction (CO2 release g/L), and fermentation parameters obtained from a modified non-linear sigmoidal equation. The analyses of the musts showed differences in the concentration of metals, total acidity, tartaric acid, AN and O.D. 420 nm. The kinetic parameters of the fermentation showed significant changes between the control must and the ion-exchange treatments. This study showed that the treatment with cationic resins at the tested level significantly affects the chemical composition of the musts, interfering with the fermentation kinetics. In addition, reductions in the must pH index close to 0.1 unit can lead to positive results in the characteristics of the base must of sparkling wines.

Yeast diversity in Vitis non-vinifera ecosystems / Diversidad de levaduras en ecosistemas de Vitis no-vinifera

The surface of grapes lodges a complex community of yeast species responsible for spontaneous alcoholic fermentation. The study of indigenous Saccharomyces and "non-Saccharomyces" yeasts during grape must fermentation constitutes a major research area in microbial enology. Although there are detailed studies on the microbiota of Vitis vinifera grapes, little is known about the diversity of yeast communities present in non-vinifera Vitis ecosystems (i.e., grapes and spontaneously fermenting grape musts). Potentially scientific and/or enological valuable yeast strains from these non-vinifera Vitis ecosystems might never be isolated from V. vinifera L. In this updated review, we summarize relevant aspects of the microbial studies conducted on V. non-vinifera grapes and spontaneously fermenting grape musts.

La superficie de las uvas aloja una comunidad compleja de especies de levaduras responsables de la fermentación alcohólica espontánea. El estudio de estas levaduras Saccharomyces y «no-Saccharomyces¼ durante la fermentación del mosto de uvas constituye un área relevante de investigación microbiológica en enología. Si bien existen estudios detallados de la microbiota de uvas de Vitis vinifera L., poco se sabe sobre la diversidad de comunidades de levaduras presentes en ecosistemas de Vitis no-vinifera (i.e., uvas y mostos en fermentación espontánea). Cepas de levaduras presentes en ecosistemas de Vitis no-vinífera, con valor potencial científico y/o enológico, podrían no estar presentes en V. vinifera L. En esta revisión actualizada, resumimos los aspectos relevantes de los estudios microbiológicos efectuados en mostos en fermentación espontánea de uvas de V. no-vinifera.

Synthesis of fructo-oligosaccharides using grape must and sucrose as raw materials.

Grape must market has been rising and there is an increasing interest to use it as a "natural" replacement for traditional sugars. Food or beverages with prebiotic compounds, including fructo-oligosaccharides (FOS), emerge as an alternative for the new health style trend. The aim of this work was to investigate whether the combination of grape must with sucrose was a suitable raw material for the synthesis of FOS. This way, a prebiotic syrup containing fructose and FOS, potentially useful for the formulation of foods and beverages, could be obtained. The main process consisted of three stages, namely conditioning of grape must (oxidation of the initial glucose concentration, stage 1), synthesis of FOS [incorporation of 20, 30 and 55% (w/w) sucrose, and 3.5% v/v Viscozyme L - 4.2 U/mg-, stage 2], and conditioning of the final product (oxidation of the glucose generated during the synthesis, stage 3). At stage 1, glucose concentration decreased from 222.8 mg/mL to 47.2 mg/mL, representing a decay of about 80% regarding the initial concentration of glucose. At stage 2, incorporating 20% (w/w) sucrose was not enough to impulse FOS synthesis. In turn, although 30 and 55% (w/w) sucrose produced very similar concentrations of total FOS (DP3 + DP4), 55% (w/w) sucrose led to higher glucose generation and less DP4 formation. Hence, 30% (w/w) sucrose was the condition selected for the synthesis and further conditioning of the obtained product (stage 3). In these conditions, the final product consisted of more than 30% of short chain FOS (19% and 13% of DP3 and DP4, respectively), 55% fructose and less than 11% of glucose and sucrose. Considering that fructose has approximately double sweetening power than glucose, the obtained syrup has a bigger sweetening power in comparison with the original grape must, also providing the prebiotic benefits of FOS.

Vitis species, vintage, and alcoholic fermentation do not drive population structure in Starmerella bacillaris (synonym Candida zemplinina) species.

The yeast species Starmerella bacillaris (synonym Candida zemplinina) is widely associated with oenological ecosystems and is frequently isolated from grape and grape must. Previous work showed that the genetic diversity of this species is high in wine environments and it is shaped by geographic location. Most analysed C. zemplinina strains, however, have been isolated from Vitis vinifera, disregarding the existence of other worldwide-distributed Vitis species used in winemaking. In this work, we address the impact of the Vitis species and geographic location on the genetic diversity of C. zemplinina. Microsatellite genotyping analysis was applied to two remarkable populations of C. zemplinina from Argentina and Portugal (Azores Archipelago), isolated from neighbouring V. vinifera and Vitis labrusca vineyards. The study also included a large population of previously characterized worldwide-isolated C. zemplinina strains. Genetic analyses confirmed that geographic localization significantly shaped the genetic diversity of C. zemplinina. No genetic differentiation on the basis of the Vitis species was recorded, indicating that C. zemplinina populations from neighbouring V. vinifera and V. labrusca vineyards are genetically homogeneous. In addition, no impact of the vintage was found on the C. zemplinina populations being both highly diversified and homogeneous during initial stages of alcoholic fermentation. Altogether, these results confirmed that winemaking-related factors (i.e., vintage, Vitis species, and alcoholic fermentation) do not impact the genetic diversity of C. zemplinina and that only geographic localization significantly shapes this yeast species.

Sugarcane must fed-batch fermentation by Saccharomyces cerevisiae: impact of sterilized and non-sterilized sugarcane must.

The presence of microbial contaminants is common in the sugarcane ethanol industry and can decrease process yield, reduce yeast cell viability and induce yeast cell flocculation. To evaluate the effect of microbial contamination on the fermentation process, we compared the use of sterilized and non-sterilized sugarcane must in the performance of Saccharomyces cerevisiae with similar fermentation conditions to those used in Brazilian mills. Non-sterilized sugarcane must had values of 103 and 108 CFU mL-1 of wild yeast and bacterial contamination, respectively; decreased total reducing sugar (TRS); and increased lactic and acetic acids, glycerol and ethanol concentrations during storage. During fermentation cycles with sterilized and non-sterilized sugarcane must, S. cerevisiae viability did not change, whereas ethanol yield varied from 74.1 to 80.2%, but it did not seem to be related to must microbial contamination. Ethanol productivity decreased throughout the fermentation cycles and was more pronounced in the last two fermentation cycles with non-sterilized must, but that may be related to the decrease in must TRS. High values of the ratio of total acid production per ethanol were reported at the end of the last two fermentation cycles conducted with non-sterilized must. Additionally, the values of wild yeast contamination increased from 102 to 103 CFU mL-1 and bacterial contamination increased from 104 to 106 CFU mL-1 when comparing the first and last fermentation cycles with non-sterilized must. In addition to the increase in microbial contamination and acid concentration, ethanol yield and yeast viability rates were not directly affected by the microbial contamination present in the non-sterilized sugarcane must.

Yeast diversity in Vitis non-vinifera ecosystems.

The surface of grapes lodges a complex community of yeast species responsible for spontaneous alcoholic fermentation. The study of indigenous Saccharomyces and "non-Saccharomyces" yeasts during grape must fermentation constitutes a major research area in microbial enology. Although there are detailed studies on the microbiota of Vitis vinifera L. grapes, little is known about the diversity of yeast communities present in non-vinifera Vitis ecosystems (i.e., grapes and spontaneously fermenting grape musts). Potentially scientific and/or enological valuable yeast strains from these non-vinifera Vitis ecosystems might never be isolated from V. vinifera L. In this updated review, we summarize relevant aspects of the microbial studies conducted on V. non-vinifera grapes and spontaneously fermenting grape musts.

Flocculation and Expression of FLO Genes of a Saccharomyces cerevisiae Mezcal Strain with High Stress Tolerance.

Mezcal is a distillate produced by spontaneous fermentation of the must obtained from stalks of Agave spp. plants that are cooked and pressed. Agave must contains a high amount of fructose and phenolic compounds, and fermentation usually occurs under stressful (and uncontrolled) environmental conditions. Yeasts capable of growing under such conditions usually display advantageous biological and industrial traits for stress tolerance such as flocculation. In this study, seven Saccharomyces cerevisiae strains isolated from mezcal must were exposed to temperatures ranging between 10 and 40 °C, and to different sugar sources (fructose or glucose). Yeasts grown in fructose increased their stress tolerance, determined by colony count in a microdrop assay, under low temperature (10 °C) compared to the growth at 40 °C on solid cultures. The most stress-tolerant mezcal strain (Sc3Y8) and a commercial wine (Fermichamp) strain, used as control, were grown under fermentation conditions and exposed to long-term temperature stress to determine their performance and their potential for flocculation. Compared to glucose, fermentation on fructose increased the metabolite accumulation at the end of culture, particularly at 40 °C, with 2.3, 1.3 and 3.4 times more glycerol (8.6 g/L), ethanol (43.6 g/L) and acetic acid (7.3 g/L), respectively. Using confocal microscopy analysis, we detected morphological changes such as aggregation and wall recognition at the level of budding scars in yeast, particularly in the Sc3Y8 strain when it was exposed to 40 °C. The analysis confirmed that this mezcal strain was positive for flocculation in the presence of Ca2+ ions. Analysis of FLO1, FLO5 and FLO11 gene expression implicated in flocculation in both Saccharomyces strains showed a strong transcriptional induction, mainly of the FLO5 gene in the mezcal Sc3Y8 strain.

Assessment of knowledge and perceptions toward generic medicines among basic science undergraduate medical students at Aruba.

OBJECTIVE: Use of generic medicines is important to reduce rising health-care costs. Proper knowledge and perception of medical students and doctors toward generic medicines are important. Xavier University School of Medicine in Aruba admits students from the United States, Canada, and other countries to the undergraduate medical (MD) program. The present study was conducted to study the knowledge and perception about generic medicines among basic science MD students. MATERIALS AND METHODS: The cross-sectional study was conducted among first to fifth semester students during February 2015. A previously developed instrument was used. Basic demographic information was collected. Respondent's agreement with a set of statements was noted using a Likert-type scale. The calculated total score was compared among subgroups of respondents. One sample Kolmogorov-Smirnov test was used to study the normality of distribution, Independent samples t-test to compare the total score for dichotomous variables, and analysis of variance for others were used for statistical analysis. RESULTS: Fifty-six of the 85 students (65.8%) participated. Around 55% of respondents were between 20 and 25 years of age and of American nationality. Only three respondents (5.3%) provided the correct value of the regulatory bioequivalence limits. The mean total score was 43.41 (maximum 60). There was no significant difference in scores among subgroups. CONCLUSIONS: There was a significant knowledge gap with regard to the regulatory bioequivalence limits for generic medicines. Respondents' level of knowledge about other aspects of generic medicines was good but could be improved. Studies among clinical students in the institution and in other Caribbean medical schools are required. Deficiencies were noted and we have strengthened learning about generic medicines during the basic science years.

Apple Aminoacid Profile and Yeast Strains in the Formation of Fusel Alcohols and Esters in Cider Production.

The amino acid profile in dessert apple must and its effect on the synthesis of fusel alcohols and esters in cider were established by instrumental analysis. The amino acid profile was performed in nine apple musts. Two apple musts with high (>150 mg/L) and low (<75 mg/L) nitrogen content, and four enological yeast strains, were used in cider fermentation. The aspartic acid, asparagine and glutamic acid amino acids were the majority in all the apple juices, representing 57.10% to 81.95%. These three amino acids provided a high consumption (>90%) during fermentation in all the ciders. Principal component analysis (PCA) explained 81.42% of data variability and the separation of three groups for the analyzed samples was verified. The ciders manufactured with low nitrogen content showed sluggish fermentation and around 50% less content of volatile compounds (independent of the yeast strain used), which were mainly 3-methyl-1-butanol (isoamyl alcohol) and esters. However, in the presence of amino acids (asparagine, aspartic acid, glutamic acid and alanine) there was a greater differentiation between the yeasts in the production of fusel alcohols and ethyl esters. High contents of these aminoacids in dessert apple musts are essential for the production of fusel alcohols and most of esters by aromatic yeasts during cider fermentation.

Evaluation of Zygosaccharomyces bailii BCV 08 as a co-starter in wine fermentation for the improvement of ethyl esters production.

Zygosaccharomyces bailii BCV 08, a yeast isolated from red wine barrels in Brazil, was evaluated as co-starter in fermentations with Saccharomyces cerevisiae. Z. bailii BCV 08 was preliminarily shown to produce high levels of esters, and the production was optimized in bench and bioreactor scales using grape must. White wine vinifications were conducted with mixed cultures containing different proportions of Z. bailii BCV 08 and an enological strain of S. cerevisiae. In all trials that contained Z. bailii BCV 08, the production of ethyl esters was enhanced in comparison to the vinification control. Our results clearly show the potential of Z. bailii BCV 08 as a mixed starter with S. cerevisiae in order to increase the aromatic complexity of wine.

Natural occurrence of ochratoxin A in musts, wines and grape vine fruits from grapes harvested in Argentina.

In this study, ochratoxin A (OTA) occurrence in Argentinean musts, wines and dried vine fruits was evaluated, alongside with the performance of OchraStar(TM) columns for OTA extraction. In all the three matrices analyzed, the OchraStar(TM) columns showed good performance. The analysis of natural occurrence of OTA in the red must and the red wine samples showed low incidence with low levels of mean OTA contamination (0.12 ng/mL and 0.37 ng/mL, respectively), while 60% of the dried vine fruit samples were contaminated with OTA, in levels ranging from 0.26 to 20.28 ng/g.

Produção e composição química da uva de videiras Cabernet Sauvignon submetidas à adubação nitrogenada / Grapes yield and chemistry composition in Cabernet Sauvignon grapevine with nitrogen fertilization

A adubação nitrogenada em videiras é realizada para suprir a demanda da planta pelo nutriente. Porém, o nitrogênio (N) deve ser usado com prudência porque afeta a produção e a composição química da uva e do seu mosto, nem sempre na mesma direção. O trabalho objetivou avaliar o efeito da aplicação de N na produção de uva, em seus componentes e na composição química do seu mosto. O experimento foi desenvolvido na safra 2004/05, em vinhedo de viníferas Cabernet Sauvignon, na área experimental da Embrapa Uva e Vinho, em Bento Gonçalves, Rio Grande do Sul (RS), sobre NEOSSOLO LITÓLICO. Os tratamentos foram testemunha, 15, 30, 45 e 60kg ha-1 de N aplicados durante o ciclo vegetativo e produtivo. Na maturação, a uva foi colhida, e o seguintes variáveis foram avaliadas: a produção por planta e por hectare, o comprimento e a largura de cachos e a massa de 100 bagas. Foram coletadas bagas de uva, sendo uma parte amassada, e no mosto foram determinados os sólidos solúveis totais, o pH, a acidez total, o ácido tartárico e málico, os polifenóis totais, as antocianinas e o N amoniacal. As bagas restantes foram trituradas, e foi analisado o total de N, P, K, Ca e Mg. Os resultados mostraram que a produção de uva de viníferas Cabernet Sauvignon em solos com teores médios de matéria orgânica é máxima com a aplicação de doses de 15 e 30kg ha-1 de N. A aplicação de N aumenta os teores de N amoniacal no mosto, mas diminui as antocianinas, e aumenta a porcentagem de K nas bagas, o que interfere na cor dos vinhos tintos e na formação de precipitados.

Fertilization of grapevines with N is generally accomplished to supply the demand for N. However N should be used with prudence because affect the yield and chemical composition of the grape and your must. The experiment was carried out in 2004/05, to evaluate the effect of N fertilization on the grape yield and on the chemical composition of the grape and must of Cabernet Sauvignon grapevines, at Udorthent soil at Southern Brazil, Bento Gonçalves city. The treatments were control, 15, 30, 45 and 60kg ha-1 N, added during the vegetative and productive period. In the maturation, the grape was collected. Grape yield by plant and by hectare, length and width of bunches were evaluated and 100 berries were weighted. Berries were collected and a part of them was used to evaluate soluble solids in the must, pH, total acidity, tartaric acid, malic acid, total phenols, anthocyanins and N ammonia. The remaining berries were triturated and used to evaluated total N, P, K, Ca and Mg. The results showed that the yield of Cabernet Sauvignon grapevines in soils with medium content of organic matter is maximum with the fertilization of 15 and 30kg ha-1 N. The N fertilization increased the values of ammonia in the must and potassium percentage in the berry, but decreased the values of anthocyanins, what interferes the color of red wines and the formation of precipitate

Produção e composição química da uva de videiras Cabernet Sauvignon submetidas à adubação nitrogenada

Fertilization of grapevines with N is generally accomplished to supply the demand for N. However N should be used with prudence because affect the yield and chemical composition of the grape and your must. The experiment was carried out in 2004/05, to evaluate the effect of N fertilization on the grape yield and on the chemical composition of the grape and must of Cabernet Sauvignon grapevines, at Udorthent soil at Southern Brazil, Bento Gonçalves city. The treatments were control, 15, 30, 45 and 60kg ha-1 N, added during the vegetative and productive period. In the maturation, the grape was collected. Grape yield by plant and by hectare, length and width of bunches were evaluated and 100 berries were weighted. Berries were collected and a part of them was used to evaluate soluble solids in the must, pH, total acidity, tartaric acid, malic acid, total phenols, anthocyanins and N ammonia. The remaining berries were triturated and used to evaluated total N, P, K, Ca and Mg. The results showed that the yield of Cabernet Sauvignon grapevines in soils with medium content of organic matter is maximum with the fertilization of 15 and 30kg ha-1 N. The N fertilization increased the values of ammonia in the must and potassium percentage in the berry, but decreased the values of anthocyanins, what interferes the color of red wines and the formation of precipitate

A adubação nitrogenada em videiras é realizada para suprir a demanda da planta pelo nutriente. Porém, o nitrogênio (N) deve ser usado com prudência porque afeta a produção e a composição química da uva e do seu mosto, nem sempre na mesma direção. O trabalho objetivou avaliar o efeito da aplicação de N na produção de uva, em seus componentes e na composição química do seu mosto. O experimento foi desenvolvido na safra 2004/05, em vinhedo de viníferas Cabernet Sauvignon, na área experimental da Embrapa Uva e Vinho, em Bento Gonçalves, Rio Grande do Sul (RS), sobre NEOSSOLO LITÓLICO. Os tratamentos foram testemunha, 15, 30, 45 e 60kg ha-1 de N aplicados durante o ciclo vegetativo e produtivo. Na maturação, a uva foi colhida, e o seguintes variáveis foram avaliadas: a produção por planta e por hectare, o comprimento e a largura de cachos e a massa de 100 bagas. Foram coletadas bagas de uva, sendo uma parte amassada, e no mosto foram determinados os sólidos solúveis totais, o pH, a acidez total, o ácido tartárico e málico, os polifenóis totais, as antocianinas e o N amoniacal. As bagas restantes foram trituradas, e foi analisado o total de N, P, K, Ca e Mg. Os resultados mostraram que a produção de uva de viníferas Cabernet Sauvignon em solos com teores médios de matéria orgânica é máxima com a aplicação de doses de 15 e 30kg ha-1 de N. A aplicação de N aumenta os teores de N amoniacal no mosto, mas diminui as antocianinas, e aumenta a porcentagem de K nas bagas, o que interfere na cor dos vinhos tintos e na formação de precipitados.

Produção e composição química da uva de videiras Cabernet Sauvignon submetidas à adubação nitrogenada

Fertilization of grapevines with N is generally accomplished to supply the demand for N. However N should be used with prudence because affect the yield and chemical composition of the grape and your must. The experiment was carried out in 2004/05, to evaluate the effect of N fertilization on the grape yield and on the chemical composition of the grape and must of Cabernet Sauvignon grapevines, at Udorthent soil at Southern Brazil, Bento Gonçalves city. The treatments were control, 15, 30, 45 and 60kg ha-1 N, added during the vegetative and productive period. In the maturation, the grape was collected. Grape yield by plant and by hectare, length and width of bunches were evaluated and 100 berries were weighted. Berries were collected and a part of them was used to evaluate soluble solids in the must, pH, total acidity, tartaric acid, malic acid, total phenols, anthocyanins and N ammonia. The remaining berries were triturated and used to evaluated total N, P, K, Ca and Mg. The results showed that the yield of Cabernet Sauvignon grapevines in soils with medium content of organic matter is maximum with the fertilization of 15 and 30kg ha-1 N. The N fertilization increased the values of ammonia in the must and potassium percentage in the berry, but decreased the values of anthocyanins, what interferes the color of red wines and the formation of precipitate

A adubação nitrogenada em videiras é realizada para suprir a demanda da planta pelo nutriente. Porém, o nitrogênio (N) deve ser usado com prudência porque afeta a produção e a composição química da uva e do seu mosto, nem sempre na mesma direção. O trabalho objetivou avaliar o efeito da aplicação de N na produção de uva, em seus componentes e na composição química do seu mosto. O experimento foi desenvolvido na safra 2004/05, em vinhedo de viníferas Cabernet Sauvignon, na área experimental da Embrapa Uva e Vinho, em Bento Gonçalves, Rio Grande do Sul (RS), sobre NEOSSOLO LITÓLICO. Os tratamentos foram testemunha, 15, 30, 45 e 60kg ha-1 de N aplicados durante o ciclo vegetativo e produtivo. Na maturação, a uva foi colhida, e o seguintes variáveis foram avaliadas: a produção por planta e por hectare, o comprimento e a largura de cachos e a massa de 100 bagas. Foram coletadas bagas de uva, sendo uma parte amassada, e no mosto foram determinados os sólidos solúveis totais, o pH, a acidez total, o ácido tartárico e málico, os polifenóis totais, as antocianinas e o N amoniacal. As bagas restantes foram trituradas, e foi analisado o total de N, P, K, Ca e Mg. Os resultados mostraram que a produção de uva de viníferas Cabernet Sauvignon em solos com teores médios de matéria orgânica é máxima com a aplicação de doses de 15 e 30kg ha-1 de N. A aplicação de N aumenta os teores de N amoniacal no mosto, mas diminui as antocianinas, e aumenta a porcentagem de K nas bagas, o que interfere na cor dos vinhos tintos e na formação de precipitados.

Produção e composição química da uva de videiras Cabernet Sauvignon submetidas à adubação nitrogenada

Fertilization of grapevines with N is generally accomplished to supply the demand for N. However N should be used with prudence because affect the yield and chemical composition of the grape and your must. The experiment was carried out in 2004/05, to evaluate the effect of N fertilization on the grape yield and on the chemical composition of the grape and must of Cabernet Sauvignon grapevines, at Udorthent soil at Southern Brazil, Bento Gonçalves city. The treatments were control, 15, 30, 45 and 60kg ha-1 N, added during the vegetative and productive period. In the maturation, the grape was collected. Grape yield by plant and by hectare, length and width of bunches were evaluated and 100 berries were weighted. Berries were collected and a part of them was used to evaluate soluble solids in the must, pH, total acidity, tartaric acid, malic acid, total phenols, anthocyanins and N ammonia. The remaining berries were triturated and used to evaluated total N, P, K, Ca and Mg. The results showed that the yield of Cabernet Sauvignon grapevines in soils with medium content of organic matter is maximum with the fertilization of 15 and 30kg ha-1 N. The N fertilization increased the values of ammonia in the must and potassium percentage in the berry, but decreased the values of anthocyanins, what interferes the color of red wines and the formation of precipitate

A adubação nitrogenada em videiras é realizada para suprir a demanda da planta pelo nutriente. Porém, o nitrogênio (N) deve ser usado com prudência porque afeta a produção e a composição química da uva e do seu mosto, nem sempre na mesma direção. O trabalho objetivou avaliar o efeito da aplicação de N na produção de uva, em seus componentes e na composição química do seu mosto. O experimento foi desenvolvido na safra 2004/05, em vinhedo de viníferas Cabernet Sauvignon, na área experimental da Embrapa Uva e Vinho, em Bento Gonçalves, Rio Grande do Sul (RS), sobre NEOSSOLO LITÓLICO. Os tratamentos foram testemunha, 15, 30, 45 e 60kg ha-1 de N aplicados durante o ciclo vegetativo e produtivo. Na maturação, a uva foi colhida, e o seguintes variáveis foram avaliadas: a produção por planta e por hectare, o comprimento e a largura de cachos e a massa de 100 bagas. Foram coletadas bagas de uva, sendo uma parte amassada, e no mosto foram determinados os sólidos solúveis totais, o pH, a acidez total, o ácido tartárico e málico, os polifenóis totais, as antocianinas e o N amoniacal. As bagas restantes foram trituradas, e foi analisado o total de N, P, K, Ca e Mg. Os resultados mostraram que a produção de uva de viníferas Cabernet Sauvignon em solos com teores médios de matéria orgânica é máxima com a aplicação de doses de 15 e 30kg ha-1 de N. A aplicação de N aumenta os teores de N amoniacal no mosto, mas diminui as antocianinas, e aumenta a porcentagem de K nas bagas, o que interfere na cor dos vinhos tintos e na formação de precipitados.

Efeito do ácido tartárico nos valores de potássio, acidez titulável e pH durante a vinificação de uvas Cabernet Sauvignon / Effect of tartaric acid upon potassium, total acidity and pH, during the vinification of Cabernet Sauvignon grapes

Vinhos tintos com altos valores de pH são resultantes de uvas com valores excessivos de potássio. O excesso de potássio é, geralmente, resultado, do manejo inadequado no vinhedo. Com o intuito de encontrar uma solução tecnológica para o problema de pH nos mostos antes e durante da aplicação de medidas no vinhedo, foram realizadas vinificações em escala piloto com uvas Cabernet Sauvignon adicionando-se ácido tartárico no momento do esmagamento. Assim, três tratamentos, em duplicata, foram feitos com a adição de zero (testemunha), 1 e 2gL-1 de ácido tartárico. Foram utilizados os procedimentos normais de sulfitagem, uso de enzimas pectinolíticas e leveduras selecionadas. A descuba foi realizada após 10 dias e a fermentação malolática foi espontânea. Foram analisados potássio (por fotometria de chama), acidez titulável (por titulometria) e pH (por peagâmetro) no mosto durante a fermentação e no vinho resultante. Potássio foi também analisado nas películas e nas borras submetidas, no entanto, a digestão nitroperclórica antes da análise. Os valores encontrados para potássio (gL-1), acidez titulável (g por cento) e pH durante a microvinificação foram, respectivamente, na amostra testemunha: 1,98, 0,61, 3,68; tratamento 1: 1,72, 0,70 e 3,63; tratamento 2: 1,41, 0,73 e 3,50. A análise de potássio, nas películas e nas borras nos diferentes tratamentos, apresentou os seguintes valores, respectivamente, para a amostra testemunha em g kg-1 (Matéria Seca): 24,91 e 69.30; tratamento 1: 21,85 e 75.11; tratamento 2: 16,20 e 85.38. A ação do ácido tartárico torna-se mais evidente nas borras, em que quanto maior foi a adição de ácido no mosto maior foi a quantidade de potássio encontrada nestas, reduzindo, desse modo, a quantidade de potássio no vinho. Salienta-se que a adição de ácido tartárico é um paliativo momentâneo e a verdadeira correção deve ser feita no vinhedo, por meio de um manejo adequado.

Wines with high pH values are usually made from grapes with high potassium values and can bring serious problems to the wine. This high potassium comes, usually, from mistakes with the vines management. While the right management has being tried, in the vineyard, and aiming to find a fast solution for the problem inside the winery a pilot scale fermentation was made with Cabernet Sauvignon. The must was submitted to three different treatments with tartaric acid: zero, 1gL-1 and 2gL-1,all in duplicate. The pattern of fermentation was the normal SO2, pectinolitic enzymes and yeasts addition to the musts; skins and seeds were removed from the must after 10 days of fermentation and malolactic fermentation occurred spontaneously. Potassium (by flame spectrometry), total acidity (by titulometry) and pH (by pH meter) were analyzed in the musts during fermentation and in the wines; skins and lees were digested previously the analysis. Values found, in the wines, for potassium (gL-1), total acidity (g percent) and pH were respectively: samples from zero tartaric acid 1,98, 0.61, 3,68; from 1gL-1:1,72, 0.70 e 3,63; from 2gL-1:1,41, 0,73 e 3,50. Values found in the skins and lees with the same treatments were, respectively: 24,91 and 69.30, 21,85 and 75.11, 16,20 and 85.38g kg-1 of the Dry Matter. The effect of tartaric acid addition was noted mainly in the lees (69.3, 75.11 and 85.38), in which the potassium found showed a close relationship with the acid added in the must. It should be noted, though, that this addition is just for the moment because the real correction should be made in the vineyard, as it is now.