The geographic distribution of saccharomyces cerevisiae isolates within three Italian neighboring winemaking regions reveals strong differences in yeast abundance, genetic diversity and industrial strain dissemination

In recent years the interest for natural fermentations has been re-evaluated in terms of increasing the wine terroir and managing more sustainable winemaking practices. Therefore, the level of yeast genetic variability and the abundance of Saccharomyces cerevisiae native populations in vineyard are becoming more and more crucial at both ecological and technological level. Among the factors that can influence the strain diversity, the commercial starter release that accidentally occur in the environment around the winery, has to be considered. In this study we led a wide scale investigation of S. cerevisiae genetic diversity and population structure in the vineyards of three neighboring winemaking regions of Protected Appellation of Origin, in North-East of Italy. Combining mtDNA RFLP and microsatellite markers analyses we evaluated 634 grape samples collected over 3 years. We could detect major differences in the presence of S. cerevisiae yeasts, according to the winemaking region. The population structures revealed specificities of yeast microbiota at vineyard scale, with a relative Appellation of Origin area homogeneity, and transition zones suggesting a geographic differentiation. Surprisingly, we found a widespread industrial yeast dissemination that was very high in the areas where the native yeast abundance was low. Although geographical distance is a key element involved in strain distribution, the high presence of industrial strains in vineyard reduced the differences between populations. This finding indicates that industrial yeast diffusion it is a real emergency and their presence strongly interferes with the natural yeast microbiota

Mineral composition through soil-wine system of portuguese vineyards and its potential for wine traceability

The control of geographic origin is one of a highest priority issue regarding traceability and wine authenticity. The current study aimed to examine whether elemental composition can be used for the discrimination of wines according to geographical origin, taking into account the effects of soil, winemaking process, and year of production. The elemental composition of soils, grapes, musts, and wines from three DO (Designations of Origin) and for two vintage years was determined by using the ICP-MS semi-quantitative method, followed by multivariate statistical analysis. The elemental composition of soils varied according to geological formations, and for some elements, the variation due to soil provenance was also observed in musts and wines. Li, Mn, Sr and rare-earth elements (REE) allowed wine discrimination according to vineyard. Results evidenced the influence of winemaking processes and of vintage year on the wine’s elemental composition. The mineral composition pattern is transferred through the soil-wine system, and differences observed for soils are reflected in grape musts and wines, but not for all elements. Results suggest that winemaking processes and vintage year should be taken into account for the use of elemental composition as a tool for wine traceability. Therefore, understanding the evolution of mineral pattern composition from soil to wine, and how it is influenced by the climatic year, is indispensable for traceability purposesinfo:eu-repo/semantics/publishedVersio

Pneumatic press equipped with the Vortex system for white grapes processing: First results

The interaction between mechanical, computer and electronic technologies offers nowadays highly innovative solutions to be applied to the oenological machinery industry. Grapes pressing for the extraction of must from the grapes has a fundamental role for obtaining wines with high quality. The pneumatic presses commonly used work with a discontinuous cycle, taking on average about 3 hours for the extraction of the juice from the grapes. During this period, the presence of oxygen in contact with grapes can modify the qualitative characteristics of the future wine. The aim of the research was to study the \u201cVortex System\u201d applied to a pneumatic press and to evaluate the quality of wines obtained in reduction. The study was carried out in a modern winery in the province of Palermo (Italy) using cv. Catarratto lucido grapes. The machine used in the tests was a pneumatic press with a capacity of 1,900 / 2,500 kg by Puleo Srl company (Italy), equipped with the patent "Vortex System". It consists in the recovery of the inert gas by means of a passage and recirculation apparatus during grapes pressing allowing the must extraction in inert and controlled atmosphere, the non-oxidation of the product and a re-use of the gaseous component. Two operating modes were applied: AP (Air Pressing) mode, the traditional pressing mode in presence of oxygen, and NP (Nitrogen Pressing) mode with the Vortex System, performed under inert gas with nitrogen recovery. The following analytical determinations were performed on wines in triplicates: alcohol [%/vol], density [g/l], sugar [g/l], pH, total acidity [g/l], volatile acidity [g/l], malic acid [g/l], citric acid [g/l], tartaric acid [g/l], potassium [g/l], glycerin [g/l], ashes [g/l], absorbance at 420, 520 and 620 nm, polyphenols [mg/l], catechins [mg/l], free sulfur dioxide [mg/l], total sulfur dioxide [mg/l]. The use of the pneumatic press equipped with the Vortex System allowed to obtain excellent values of volatile acidity, absorbance at 420 nm, catechins in white wines and a rich aromatic component both in primary and secondary aromas

Fluoride inhibition of wine yeasts : a thesis presented in partial fulfilment of the requirements for the degress of Master of Science in Microbiology at Massey University

Stuck or slowed fermentations are costly in time and money to winemakers. There are many variables that can interrupt fermentation. One of the lesser known factors is the effect of fluoride on grape juice fermentations. Winemakers in California have had problems with slow or stuck fermentations with grapes that have been treated with the insecticide Cryolite, which contains fluoride. A selection of 6 yeasts, 3 commercial strains and 3 natural strains, commonly associated with winemaking were used in this study. Preliminary experiments investigated a wide range of fluoride challenge with different pH and cell densities on solid and liquid media. The effectiveness of fluoride was compared between sodium fluoride and Cryolite, as the fluoride source. The effect of fluoride was more potent with sodium fluoride, as the fluoride source. The minimum inhibitory concentration of fluoride for the yeast strains was recorded. The most sensitive commercial yeast was Saccharomyces cerevisiae RS1, the most resistant commercial yeast was Saccharomyces bayanus RS2. The most sensitive yeast overall was Hansenula saturnus AWRI-354. The next stage examined the effect of fluoride on the selected yeast in small scale grape juice fermentations. Within this investigation the effect of different media sources and heat treatments was included. Fluoride concentrations reflected levels of fluoride found in grape musts and wines. During this study we found that the effect of fluoride on yeasts is increased with lower pH and lower cell densities. The effect of fluoride on yeast growth and fermentation was also strain dependent

Superheated liquids for the extraction of solid residues from winemaking processes

Solid residues from winemaking process have been subjected to extraction with superheated water-ethanol mixtures. Identification and characterisation of the extracted compounds have been made by spectrophotometry, gas chromatography with either flame ionisation or mass detectors and high performance liquid chromatography with UV detection. The extraction has been performed in a static manner by single or repetitive cycles. All variables affecting the extraction process have been studied and optimised. The extraction time and temperature are 65 min and 210ºC, respectively. Two phases constitute the extract: an aqueous phase, which is rich in phenol compounds and an oily phase, mainly formed by fatty acids. The method allows manipulation of the extract composition by changing the applied pressure, temperature, water-ethanol ratio and pH. The method is faster than the traditional extraction procedures for obtaining valuable compounds from these residues

Influence of sodium chloride on wine yeast fermentation performance

This paper concerns research into the influence of salt (sodium chloride) on growth, viability and fermentation performance in a winemaking strain of the yeast, Saccharomyces cerevisiae. Experimental fermentations were conducted in both laboratory-scale and industrial-scale experiments. Preculturing yeasts in elevated levels of sodium chloride, or salt “preconditioning” led to improved fermentation performance. This was manifest by preconditioned yeasts having an improved capability to ferment high-sugar containing media with increased cell viability and with elevated levels of produced ethanol. Salt-preconditioning most likely influenced the stress-tolerance of yeasts by inducing the synthesis of key metabolites such as trehalose and glycerol. These compounds may act to improve cells’ ability to withstand osmostress and ethanol toxicity during fermentations of grape must. Industrial-scale trials using salt-preconditioned yeasts verified the benefit of this novel physiological cell engineering approach to practical winemaking fermentations

Economic contributions and characteristics of grapes and wine in AustraliaÂ’s wine regions

Over the past two decades, the Australian wine industry has been through a remarkable period of export-oriented growth. Even when vines for drying and table grapes are included, the vineyard area in Australia has trebled over the 20 vintages to 2008, the biggest surge in Australia’s history. In the first half of the 1980s, barely 2 percent of the country’s wine production was exported, which was less than the volume it imported. Today, nearly two-thirds of Australia’s production is exported – and production itself has increased nearly four-fold since the early 1980s. Prepared for the Grape and Wine Research and Development Corporation (GWRDC), Winemakers Federation of Australia (WFA) and the Australian Wine and Brandy Corporation (AWBC). The authors are grateful for funding from GWRDC (Project Number UA08/04) and the University of Adelaide’s Wine2030 project, and for helpful comments from Leanne Webb of CSIRO, Jim Fortune, and members of the project’s Industry Reference Group.

Valorization of American Barrel-Shoot Wastes: Effect of Post Fermentative Addition and Readdition on Phenolic Composition and Chromatic Quality of Syrah Red Wines

The influence of post fermentative addition of American barrel-shoot wastes on phenolic composition and chromatic quality of Syrah red wines has been evaluated as an environmentally sustainable alternative to the conventional winemaking for avoiding the common color loss of red wines elaborated in warm climates. American oak wood byproducts added were previously classified by hyperspectral image analysis according to the amount of phenolic compounds transferred to the extraction media. After that, wines were elaborated under different maceration conditions by applying only one proportion of wood (12 g L−1) and two different maceration procedures (simple and double addition) and were compared with a traditionally macerated Syrah red wine (CW, no wood addition). Results proved the effectiveness of the moderate postfermentative addition of oak wood byproducts to stabilize the color of wines and to provoke lower color modification along the time, producing color wines chromatically more stable for a better aging. In the case of double addition, the adsorption of the pigments during the maceration presents a stronger effect on the color than copigmentation and polymerization by cause of the copigments extracted from the woodEspaña, Ministerio de Economía y Competitividad AGL2017-84793-C

2010 International Pinot Noir Celebration Program

This document is the 2010 program for the International Pinot Noir Celebration (IPNC), held annually on the campus of Linfield College in McMinnville, Oregon. The program contains a detailed schedule of the celebration’s major events, presentations, and meals, as well as information regarding guest speakers, chefs, and artists visiting the campus. The program also includes a short description of all participating wineries for 2010, both foreign and domestic, along with a listing of the IPNC board of directors and all major supporters and contributors to the event

Characterization of the killer toxin KTCf20 from wickerhamomyces anomalus, a potential biocontrol agent against wine spoilage yeasts

Wickerhamomyces anomalus Cf20 secretes the killer toxin KTCf20 that inhibits several wine spoilage yeasts of the species Pichia guilliermondii, P. membranifaciens, Brettanomyces bruxellensis and Dekkera anomala. KTCf20 binds cell wall extracts from the sensitive target P. guilliermondii Cd6; however, this capacity was lost when cell wall extracts were pre-treated with fungal β-glucanase. Pustulan and laminarin inhibited killer activity, suggesting that β-1,3 and β-1,6-glucans may be the putative binding sites for KTCf20 on the cell wall of sensitive cells. The toxin was produced and showed to be stable and highly active at physicochemical conditions suitable for winemaking process. In addition, the strain Cf20 is compatible with Saccharomyces cerevisiae in co-culture conditions being potential its application in a mixed starter culture. These data suggest that W. anomalus Cf20 and/or KTCf20 are promising biocontrol agents against spoilage yeasts during wine-making process.Fil: Fernandez de Ullivarri, Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Mendoza, Lucia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Raya, Raul Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin