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.

Lactobacillus plantarum as a malolactic starter culture in winemaking: a new (old) player?

Malolactic fermentation (MLF) is a process in winemaking responsible for the conversion of L-malic acid to L-lactic acid and CO2, which reduces the total acidity, improves the biological stability, and modifies the aroma profile of wine. MLF takes place during or after alcoholic fermentation and is carried out by one or more species of lactic acid bacteria (LAB), which are either present in grapes and cellars or inoculated with malolactic starters during the winemaking process. Although the main bacterium among LAB used in commercial starter cultures for MLF has traditionally been Oenococcus oeni, in the last decade, Lactobacillus plantarum has also been reported as a malolactic starter, and many works have shown that this species can survive and even grow under harsh conditions of wine (i.e., high ethanol content and low pH values). Furthermore, it has been proved that some strains of L. plantarum are able to conduct MLF just as efficiently as O. oeni. In addition, L. plantarum exhibits a more diverse enzymatic profile than O. oeni, which could play an important role in the modification of the wine aroma profile. This enzymatic diversity allows obtaining several starter cultures composed of different L. plantarum biotypes, which could result in distinctive wines. In this context, this review focuses on showing the relevance of L. plantarum as a MLF starter culture in winemaking.

Yield and physicochemical characteristics of 'BRS Magna' and 'Isabel Precoce' grapes influenced by pruning in the SãoFrancisco river valley / Produtividade e características físico-químicas das uvas 'BRS Magna' e 'Isabel precoce' influenciadas pela poda no Vale do São Francisco

ABSTRACT: The objective of this study was to evaluate the productive performance and physicochemical characteristics of 'BRS Magna' and 'Isabel Precoce' grapes influenced by two types of pruning. The experiment was carried out during two growing seasons in a commercial vineyard of Petrolina, PE, in the period 2013-2014. Treatments were represented by two cultivars, 'Isabel Precoce' and 'BRS Magna', and two types of pruning, with selection during plant formation (P1) and without selection (P2) of lateral branches, using a randomized experimental block design, in subdivided plots and four replicates. After pruning P2, the amount of buds kept on vines was greater than after pruning P1, favoring an increase in yield. However, the sizes of bunches and berries, content of soluble solids, and titratable acidity were not influenced by the pruning type. In general, the sizes of bunches and berries in 'BRS Magna' were larger than in the 'Isabel Precoce' cultivar. Conversely, content of soluble solids and titratable acidity varied among cultivars as a function of production cycle and type of pruning; however, within the standards described for both cultivars and accepted by the Brazilian legislation.

RESUMO: O presente trabalho teve como objetivo estudar o desempenho produtivo e características físico-químicas das uvas 'BRS Magna' e 'Isabel Precoce' submetidas a dois tipos de poda. Um experimento foi realizado durante dois ciclos de produção, nos anos de 2013 e 2014, em um vinhedo comercial em Petrolina, PE. Os tratamentos foram representados por duas cultivares copa, 'Isabel Precoce' e 'BRS Magna', e dois tipos de poda, com seleção de ramos laterais na formação da planta (P1) e sem seleção de ramos laterais (P2), utilizando delineamento experimental em blocos ao acaso em parcelas subdivididas e quatro repetições. A quantidade de gemas mantidas na videira após a poda é mais elevada na poda P2, favorecendo o aumento da produtividade, mas o tamanho dos cachos e das bagas e o teor de sólidos solúveis e acidez titulável não foram influenciados pelo tipo de poda. O tamanho dos cachos e das bagas da cultivar 'BRS Magna' é, de modo geral, maior que os de 'Isabel Precoce'. Por outro lado, o teor de sólidos solúveis e acidez titulável variaram entre as cultivares em função do ciclo de produção e do tipo de poda, estando dentro dos padrões descritos para ambas cultivares e aceitos pela legislação brasileira.

Bioactive compounds of red grapes from Dão region (Portugal): Evaluation of phenolic and organic profile

Objective: To improve the knowledge on the metabolite profile of five red grapes from Dão region (Portugal), concerning to the phenolic characteristics (coloured and non-coloured phenolics) and organic acid composition. Methods: Five red grapes collected from Dão region were studied. The profiles of phenolic compounds and organic acids were estimated by high-performance liquid chromatography with diode-array detection and high-performance liquid chromatography with UV detector, respectively. Results: Totally 24 phenolic compounds were identified, and distributed by several classes: 8 anthocyanins, 1 hydroxybenzoic acid, 4 hydroxycinnamic acids, 1 stilbene, 4 flavan-3-ols, 6 flavonols. Additionally, 10 organic acids were detected in all samples. Total contents of each phenolic class and organic acids amounts varied significantly among the different grape cultivars investigated. The principal components analysis differentiates the Touriga Nacional from the other varieties due to their high contents in anthocyanins, non-coloured phenolics and organic acids. Touriga Nacional is an important red grape cultivar, highly esteemed in Dão region for its ability to produce high quality wines. Conclusions: The results suggest that the red grapes from Dão region present a good composition in bioactive compounds, being important for the production of wines with superior quality.

Necessidades térmicas de videiras na região da Campanha do Rio Grande do Sul - Brasil / Thermal requirement of vines in the Rio Grande do Sul region Campaign - Brazil

A vitivinicultura, reconhecida por sua importância econômica e social no Rio Grande do Sul, tem ampliado sua fronteira de produção para a região da Campanha. Objetivou-se com o presente trabalho avaliar o comportamento fenológico, bem como a necessidade térmica em graus-dia e a necessidade em dias, de cultivares de uvas finas destinadas à produção de vinhos, quando cultivadas na região da Campanha, local de recente introdução da espécie com caráter econômico. Os dados utilizados foram coletados em um vinhedo comercial, localizado no município de Dom Pedrito - RS, Brasil, durante as safras de 2007/2008, 2008/2009, 2009/2010, 2010/2011 e 2011/2012. Foram utilizadas as cultivares, 'Cabernet Sauvignon', 'Tannat', 'Tempranillo', 'Merlot', 'Gewurztraminer', 'Sauvignon Blanc' e 'Chardonnay'. Os resultados demonstram que as cultivares respondem de forma diferente quanto à necessidade térmica, em Graus-dia (GD), e à necessidade em dias para completar o ciclo, necessitando, em média, respectivamente, 2084 GD e 174 dias para a 'Cabernet Sauvignon', 1937 GD e 166 dias para 'Tempranillo', 1893 GD e 161dias para a 'Merlot', 1793 GD e 156 dias para 'Tannat', 1759 GD e 147 dias para a 'Sauvignon Blanc', 1689 GD e 152 dias para a 'Chardonnay' e 1606 GD e 145 dias para a 'Gewurztraminer'. A maior necessidade térmica é na fase de desenvolvimento do fruto e maturação do fruto e a menor necessidade, na fase de floração.

The vitiviniculture, recognized for its economic and social importance in Rio Grande do Sul, has increased its production in the frontier of campaign region. The present study aimed to evaluate the phenological behavior, as well as the need for thermal degree-days and the need in days of cultivars of fine grapes intended for production wine, when cultivated in the campaign, local recent in the introduction of this species of economic nature. Data were collected in a commercial vineyard located in Dom Pedrito - RS, Brazil, during the growing seasons of 2007/2008, 2008/2009, 2009/2010, 2010/11 and 2011/12. The species cultivated were, 'Cabernet Sauvignon', 'Tannat', 'Tempranillo', 'Merlot', 'Gewurztraminer', 'Sauvignon Blanc' and 'Chardonnay'. The results demonstrated that cultivars responds differently to the need for thermal days to complete the cycle, requiring on average 2084 and 174 respectively for Cabernet Sauvignon, 1937 and 166 for 'Tempranillo', 161 and 1893 to 'Merlot', and 156 to 1793 for 'Tannat', and 147 to 1759 for 'Sauvignon Blanc', and 152 to 1689 for 'Chardonnay' and 145 to 1606 for 'Gewurztraminer'. The greatest need regarding thermal necessities is to fruit development and ripening and less need to flowering stage.

Relative humidity during cold storage on Postharvest quality of 'Niagara Rosada' table grapes / Umidade relativa durante o armazenamento refrigerado sobre a qualidade pós-colheita de uvas de mesa 'Niagara Rosada'

This study aimed to evaluate the effect of different levels of relative humidity (RH) on the maintenance of Postharvest quality of 'Niagara Rosada' table grapes after cold storage at 0.5°C for 21 days. A completely randomized design was used, with five replicates of 18 clusters per treatment. The selected levels of relative humidity were 85, 90, 95 and 100%, obtained by means of electronic humidity controllers. The fruits were evaluated in relation to rot incidence, berry cracking, browning rate, respiratory rate, titratable acidity, soluble solids, resistance to abscission, berry drop and weight loss. The evaluations were assessed at 20 days of storage and after two and four days of shelf-life (20°C; 85% RH). The results showed that as higher as relative humidity, higher is rot incidence and that the variables rachis browning and weight loss were inversely related to relative humidity. Resistance to abscission at the end of storage was higher when humidity ranged between 90 and 95%, but it was not affected after transfer to shelf-life from cold storage. Relative humidity ranging between 90 and 95% offer the best conditions to maintain the Postharvest quality of 'Niagara Rosada' table grapes.

Este trabalho teve como objetivo avaliar o efeito de diferentes níveis de umidade relativa (UR) sobre a manutenção da qualidade pós-colheita de uvas de mesa 'Niagara Rosada', após armazenamento sob refrigeração, a 0,5°C durante 21 dias. Foi utilizado delineamento inteiramente casualizado, com cinco repetições de 18 cachos por tratamento. Os níveis de umidade relativa utilizados foram 85, 90, 95 e 100%, conseguidos com o auxílio de controladores eletrônicos. Os frutos foram avaliados quanto à incidência de podridões e rachaduras, índice de escurecimento, taxa respiratória, acidez titulável, sólidos solúveis, resistência ao degrane, degrane e perda de massa. As avaliações foram realizadas aos 20 dias de armazenamento e após dois e quatro dias de exposição dos frutos à condição ambiente (20°C; 85% UR). Os resultados indicaram que quanto maior o teor de umidade, maior a incidência de podridões, e que as variáveis escurecimento da ráquis e perda de massa possuem relação inversa à umidade relativa. A resistência ao degrane na saída da câmara foi maior com umidade entre 90 e 95%, mas não foi afetada após a transferência dos cachos à condição ambiente. O armazenamento sob refrigeração e umidade relativa na faixa de 90 a 95% proporciona melhor manutenção da qualidade pós-colheita de uvas 'Niagara Rosada'.

Impact of pectolytic enzyme on the fermentation time and free-run juice rate of Sharad red wine.

We evaluated the effect of addition of commercially available pectolytic enzyme preparations in the must from Sharad variety, cultivated in India and its influence on some oenological parameters of red wine. The small scale fermentations demonstrated marked difference of organoleptic (colour) and rheologic characteristics (filterability, settling rates) and aroma between enzyme treated samples and control samples. We observed 29% enhancement in free-run juice yield and a remarkable 43% reduction in the fermentation time compared to the control. This biotechnological approach has demonstrated the economic feasibility and the benefits of adding 0.05 g. Kg-1 grapes pectolytic enzyme in terms of yield, aroma, colour, clarity and fermentation period.

Antioxidant potential of different grape cultivars against Fenton-like reagent-induced liver damage ex-vivo.

The phytochemicals present in the grapes are responsible for nutraceutical and health benfits due to their antioxidant properties. These phytochemicals, however, vary greatly among different cultivars. In this study, we evaluated the antioxidant potential and protective role of four different Indian grape (Vitis vinifera) cultivars extracts, namely Flame seedless (Black grapes), Kishmish chorni (Black with reddish brown), Red globe (Red) and Thompson seedless mutant (Sonaka, Green) against the Fenton-like reagent (200 mmole H2O2, 2 mmole ascorbate, 25 mmole FeSO4)-induced liver damage. Non-enzymatic antioxidants, such as glutathione (GSH) levels and activities of antioxidant enzymes, such as glutathione S-transferase (GST) and superoxide dismutase (SOD), as well as total antioxidant capacity (TAC) were highest in the grape seed, followed by skin and pulp. Among edible parts of different cultivars, skin of Flame seedless (Black) cultivar showed highest antioxidant potential, while the Thompson seedless the least potential. These antioxidants were found to be significantly (P<0.01) correlated with the levels of total phenol, flavonoids and ascorbic acid. Fenton-like reagent treatment significantly (P<0.001) decreased GSH content by 39.1% and activities of catalase (CAT) by 43.2% and glutathione reductase (GR) by 60%, while increasing thiobarbituric acid reactive substances (TBARS) and nitric oxide levels by 2.13-fold and 0.64-fold, respectively and GST activity by 0.81-fold. Pre-treatment with grape seed extracts showed the best hepatoprotective action against Fenton-like reagent-induced damage, followed by the extracts of skin and pulp of any cultivar. Thus, our study showed the significant amounts of antioxidants were in grape seed, followed by its skin and pulp, which varied among the cultivars and was associated with the protective action of grape extracts against Fenton-like reagent-induced liver damage ex-vivo.

Acute effect of a grape concentrate intake on oxidative stress markers in triathletes / Efeito agudo da ingestão de concentrado de uva sobre os biomarcadores do estresse oxidativo em triatletas

The aim of this crossover study was to evaluate the effect of a grape concentrate (test drink [TD]) on oxidative stress markers (thiobarbituric acid reactive substances [TBARS], catalase [CAT], superoxide dismutase [SOD], and glutathione [GSH]). Six triathletes had their physical fitness, body fat composition (%BF) and food intake evaluated. Afterwards, the athletes received two doses of 300 mL of the TD (45.8g of polyphenols/kg) or a placebo drink (PL), at breakfast and after a training session (100 km of cycling, 6 km of running and 1.5 km of swimming). Blood samples (5 ml) were collected after an overnight fasting, immediately after exercise, and one hour after exercise. The triathletes presented the following characteristics (mean and standard-deviation): 43.8±10.2 years old, VO2máx 45±5.15 mL/kg/min, %BF 13.6±4.2 %, training 270.8±87.1 km/week, 3.1±1.88 hours/training/day. There was a significant increase in SOD from the 1st to the 2nd (p=0.027) and 3rd (p=0.02) blood tests, in response to exercise, regardless of the drink consumed. One hour after exercise, the increase in glutathione values was greater when the PL was consumed (27.5%) in relation to the TD intake (1.8%). In both tests, exercise increased TBARS values; however, when PL was consumed, subjects' values were higher (PL=2.5±1.1 nmol/ml vs. BT=1.77±1.3 nmol/ml). When PL was consumed, mean CAT values (BT=34.2±6.9 U/mgHb vs. PL=24.6±12.5 U/mgHb) reduced from the 1st to the 2nd blood test (28.6%). TBARS, CAT and GSH values suggest that the TD presents potential to modulate exercise-induced oxidative stress.

O objetivo deste estudo crossover foi avaliar o efeito de um concentrado de uva (bebida teste - BT) sobre biomarcadores do estresse oxidativo (substâncias reativas ao ácido tiobarbitúrico - TBARS, catalase - CAT, superóxido dismutase - SOD e glutationa - GSH). Seis triatletas do sexo masculino foram avaliados quanto à aptidão física, percentual de gordura (%G) e ingestão alimentar. Posteriormente, em duas ocasiões, os atletas receberam duas doses de 300 ml de BT (45,8g de polifenóis/kg) ou bebida placebo (PL) no desjejum e após uma sessão de treinamento (100 km de ciclismo, 6 km de corrida e 1,5 km de natação). Amostras de sangue (5 ml) foram coletadas em jejum, imediatamente após o exercício e 1h após o mesmo. Caracterização da amostra: idade: 43,8±10,2 anos, VO2máx: 45±5,15 ml/kg/min, %G: 13,6±4,2%, volume de treino: 270,8±87,1 km/semana e 3,1±1,88 horas/treino/dia. Houve aumento significativo da atividade de SOD da 1ª para as 2ª (p=0,027) e 3ª coletas (p=0,02) em resposta ao exercício, independente da bebida consumida. Os valores de GSH foram superiores 1 hora após o exercício quando houve consumo do PL (27,5%) em relação ao consumo da BT (1,8%). Ainda, o exercício elevou as concentrações de TBARS, mas no grupo PL os valores médios foram superiores (PL=2,5±1,2 nmol/ml vs. BT=1,77±1,3 nmol/ml). Em relação à atividade da CAT, os valores médios (BT=34,2±6,9 U/mgHb vs. PL=24,6±12,5 U/mgHb) foram menores quando comparadas 1ª e 2ª coletas (28,6%) para os atletas que consumiram PL. Os resultados referentes à concentração de TBARS, atividade de CAT e níveis de GSH sugerem que a BT modulou o estresse oxidativo induzido pelo exercício.

Effect of Thymol and Linalool Fumigation on Postharvest Diseases of Table Grapes

Several postharvest diseases of table grapes (Vitis vinifera) occur during storage, and gray mold rot is a particularly severe disease because the causal agent, Botrytis cinerea, grows at temperatures as low as 0degrees C. Other postharvest diseases, such as those caused by Penicillium spp. and Aspergillus spp., also often lead to deterioration in the quality of table grapes after harvest. The use of plant essential oils such as thymol and linalool, to reduce postharvest diseases in several kinds of fruits, including table grapes and oranges, has received much attention in European countries. However, to the best of our knowledge there has been no report of the use of thymol fumigation to control gray mold in table grapes in Korea. Thymol (30 microg/mL) and linalool (120 microg/mL) significantly inhibited mycelial growth and conidia germination of B. cinerea. The occurrence rate of gray mold rot of B. cinerea and other unknown fungi was significantly reduced by fumigation with 30 microg/mL thymol in several table grape cultivars, such as Campbell early, Muscat Bailey A, Sheridan, and Geobong. In this study, fumigation with 30 microg/mL thymol, had no influence on the sugar content and hardness of grapes, but reduced fungal infection significantly. This suggests that 30 microg/mL thymol could be utilized to reduce deterioration of grapes due to gray mold and other fungal infections during long-term storage.