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Shaping bacterial and fungal communities in soils

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Aim: The present study was conducted to assess whether the vineyard soil microbiome was altered by the use of biostimulants and/or irrigation management. Background and Methods: Vineyard-living microbiota affect grapevine health and adaptation to changing environments and determine the biological quality of soils that strongly influence wine quality. However, their abundance and interactions may be affected by vineyard management. The present study was conducted to assess whether the vineyard soil microbiome was altered by the use of biostimulants (arbuscular mycorrhizal fungi (AMF) inoculation vs. non-inoculated) and/or irrigation management (fully irrigated vs. half irrigated).   Results: Bacterial and fungal communities in vineyard soils were shaped by both time course and soil management (i.e., the use of biostimulants and irrigation). Regarding alpha diversity, fungal communities were more responsive to treatments, whereas changes in beta diversity were mainly record

Effect of temperature on grapevine phenology

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Background & Aim: The variability of grapevine phenological stages under climate change has been studied in many winegrowing regions, with many reporting an advancement of the major phenological stages, particularly flowering, veraison and harvest. This study aimed to compare these regional patterns to integrate our understanding of grapevine responses. Methods: Average daily January–March (JFM) mean temperatures were correlated with day of year budburst (DBUD) and average daily springtime March–May (MAM) maximum temperatures were correlated with day of year flowering (DFLO), day of year veraison (DVER) and day of year harvest (DHAR) for 17 vineyards and showed an advancement of the associated phenological stage with increased temperature for each index.   Results: There were significant differences between vineyard groups for the rate of advancement of DBUD, DVER and DHAR which suggests that the response of phenological stage to temperature is not linear and varies b

Impacts of added oenological tannins on red wine quality to counteract Botrytis infection in Merlot grapes

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Background: The contamination of grape berries by  Botrytis cinerea  can drastically damage wine quality, in particular causing colour degradation. In musts obtained from botrytised grapes, SO 2  addition is the main means of avoiding oxidation damage due to laccases excreted by the pathogen. However, consumers are becoming increasingly reluctant to accept SO 2  addition to wine. Oenological tannins are used for fining wines because of their colloidal properties, and for wine colour stabilisation due to their ability to condense with anthocyanins. They are also known for their antioxidant and antioxidasic properties. They were thus investigated in the present study for their potential as an alternative to SO 2  against laccase oxidation. Experimental layout: The impact of various types of oenological tannins on musts and wines was studied once added to musts obtained from the Merlot cultivar, comprising 20 % and 50 % botrytised grapes. Laccase activity, antioxidant capacity, compositio

Impact of L. thermotolerans strain and lactic acid concentration on O. oeni and MLF in wine

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Background: The yeast  Lachancea thermotolerans  can produce lactic acid during alcoholic fermentation (AF) and thereby acidify wines with insufficient acidity. However, little is known about the impact of  L. thermotolerans  on  Oenococcus oeni , the primary lactic acid bacterium used in malolactic fermentation (MLF). This study explored the impact of sequential cultures of  L. thermotolerans  and  Saccharomyces cerevisiae  on MLF performance in white and red wines. Results: Four  L. thermotolerans  strains were tested in Sauvignon blanc with sequential  S. cerevisiae  inoculation, compared to an  S. cerevisiae  control and the initially un-inoculated treatments. The  L. thermotolerans  wines showed large differences in acidification, and progression of MLF depended on lactic acid production, even at controlled pH. The highest and lowest lactic acid producing strains were tested further in Merlot fermentations with both co-inoculated and sequentially inoculated  O. oeni . The low lact

Using wine lees as an antioxidant in deer burgers

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  Consumers in Europe are constantly looking for healthier alternatives to traditional meat products. Venison from wild red deer has become popular over the past few years. The meat is considered “natural” because it is obtained from free-range animals that are free of hormones, antibiotics, and other products. Burgers from meat, and in this case red deer, are popular because of convenience and price. However, the processing (high fat content) and packaging of burgers make it more susceptible to oxidation. As a result, additives are added to extend the shelf life of patties. Consumers prefer natural antioxidants to synthetic ones and in this study wine lees were studied as a natural possibility.   Raw materials and ingredients: Burgers were prepared from red deer meat and pork fat. Specifically boneless legs of wild stags and fat from female pigs. Yeast lees ( Saccharomyces cerevisiae ) from verdejo and palomino wines were included in the burgers in different amounts, replacing t

Harvesting to obtain specific wine sensory profiles

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This study aimed to investigate the possible existence of reproducible aromatic red wine styles, focusing on fresh fruit aromas and mature fruit aromas ( i.e. , with dark, jammy fruit characteristics) and taking into account both vintage and vineyard.   Methods: The study was performed on Australian Shiraz and Cabernet‑Sauvignon from three different meso-climate areas and two consecutive vintages. Sequential harvests were carried out based on the plateau of the physiological indicator berry sugar accumulation (mg/berry) in order to obtain fresh fruit and mature fruit wine sensory profiles. Results: There was a predictable aromatic sequence during grape ripening at each of these two distinct maturity stages regardless of grape genotype (variety) and environment (vineyard and vintage). The post-plateau period of berry sugar accumulation was found to be crucial for the evolution of wine aromatic profiles. During this period, wine aromatic and phenolic maturity were uncoupled fr

Effect of external factors on trunk disease expression in Chardonnay

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The aim of this study was to determine the relationship between irrigation practices and climate, and the expression of Grapevine Trunk Diseases (GTDs) in Chardonnay vines. Background: Esca disease and Botryosphaeria dieback are currently considered as serious grapevine diseases which affect vineyard health and induce economic losses. Both of these trunk diseases (GTDs) are caused by a complex of pathogens, and foliar expression is influenced by several factors, including environmental factors such as water stress. To manage water stress in some vine areas, culture practice based on irrigation systems for limiting water stress have been developed; however, little knowledge of the influence of such systems on GTD emergence is currently available. The present paper addresses the impact of irrigation systems and climatic factors (rainfall and temperature) on the expression of GTDs, specifically esca and Botryosphaeria dieback. Methods: A field experiment on Chardonnay in North Eas