Search results for "wine"
showing 10 items of 1468 documents
Typical metabolic traits of two Oenococcus oeni strains isolated from Valpolicella wines
2004
Aims: Physiological comparison of two indigenous Oenococcus oeni strains, U1 and F3 isolated in the same area (Valpolicella, Italy) in order to select a performant starter for MLF in wine. Methods and Results: Growth rate, sugar and malate metabolism in FT80 media at pH 5·3 and 3·5 were analysed. The amount of total protein synthesized and the level of expression of the small Hsp Lo18 were evaluated by radiolabelling and immunodetection experiments after heat (42°C), acid (pH 3·5) and ethanol (12% v/v) stresses. Strain U1 showed significantly lower specific growth rate and growth yield in acid conditions than strain F3. However, strain U1 had a higher malate consumption capacity at pH 3·5…
Molecular Identification and Characterization of Wine Yeasts
2011
The transformation of grape must into wine is a complex microbiological process involving the sequential growth of bacteria and yeasts, although only the yeasts are responsible for alcoholic fermentation. In the past, winemaking was purely empirical, but it is now a well-understood, controlled process that has been gradually improved over time. Advances have largely been made possible by the development of molecular techniques to identify and characterize wine yeasts based on analysis of their DNA. These methods are rapid, reproducible, and sensitive, and continue to be used for a variety of purposes, such as analyzing variation in naturally occurring and inoculated yeast populations, monit…
The effects of freezing and freeze-drying ofOenococcus oeniupon induction of malolactic fermentation in red wine
2000
Summary The use of Oenococcus oeni starter cultures for the induction of malolactic fermentation (MLF) in wine permits control over the timing of the process and the quality of the wine. Successful inoculation of bacterial starter cultures into wine depends on the selection of suitable strains and on the preparation and conservation of those cultures. Medium for Leuconostoc oenos (MLO) is the best medium for easy and rapid growth of O. oeni cultures under laboratory controlled conditions for isolation and identification. However, this study showed that O. oeni cells inoculated in MLO failed to induce MLF in wine while cells grown in Medium of Preculture (MP) or wine, stored at −20 °C or fre…
Influence of epigallocatechin gallate and phenolic compounds from green tea on the growth of Oenococcus oeni
2007
Aims: To investigate the effect of phenolic compounds on the growth of Oenococcus oeni. Methods and Results: Oenococci are usually grown in media often supplemented with complex additives such as tomato juice. In order to improve our knowledge about the growth requirements of oenococci, we added several juices and leaf extracts such as green tea to the culture media and screened them for growth-stimulating substances to substitute complex supplements such as juices by more defined components. We found that also green tea could cause a growth stimulation of Oenococcus oeni strain B2. Conclusions: Further experiments showed that the stimulating effect was as a result of the phenolic compou…
Manganese-dependent growth of Oenococci
2005
Abstract Oenococci are usually grown in complex media supplemented with tomato juice. The manganese concentration of tomato juice is about 10 µM, which shows a growth-stimulating effect. Unexpectedly, we found that high concentrations of manganese (34 mM) could replace tomato juice. At this concentration, far exceeding the concentration in growth media, several Oenococcus oeni strains yielded the same cell density as in the presence of tomato juice. The observed significant differences in the manganese dependence should also have an impact on the growth of oenococci in must and wine, where they are used as starter cultures for the removal of malic acid.
Analysis of the filtration efficiency of white wines using different filter aids
2010
The global wine market, having recently entered into full crisis, is suffering some changes in its production and marketing. The reasons for these changes are mainly due to new trends in consumer demand for wine safety and quality standards at low cost. Social cellars, in order to be included in this new trend, should focus on the rationalization of the production techniques to reduce the costs and improve the quality of wine. In the case of winemaking for the production of a wine stored in a bag-in-box, filtration is a very important technique because it gives the finished product clearness and stability. The experimentation was based on the application of a low cost filtration technique o…
Recent Advances in Yeast Biomass Production
2011
Yeasts have been used by humans to produce foods for thousands of years. Bread, wine, sake and beer are made with the essential contribution of yeasts, especially from the species Saccharomyces cerevisiae. The first references to humans using yeasts were found in Caucasian and Mesopotamian regions and date back to approximately 7000 BC. However, it was not until 1845 when Louis Pasteur discovered that yeasts were microorganisms capable of fermenting sugar to produce CO2 and ethanol. Ancient practices were based on the natural presence of this unicellular eukaryote, which spontaneously starts the fermentation of sugars. As industrialisation increased the manufacture of fermented products, th…
The production and marketing of organic wine in Sicily
2002
This paper aims at a better knowledge of the organic wine sector in Sicily. In the last few years regulations 2078/92 and 2092/91 have had a wide diffusion in the agricultural regional context; a rapid increase of areas and farms justify the attention paid by the European union policies. Two aspects of the sector have been examined: the influence on the implementation of Reg. 2078/92 with regard to diffusion of the organic wine sector in Sicily; and a group of farms in the west of Sicily have been analysed to verify the scenario of organic wine, and the strategy used in the commercialization of organic production. The results show a very interesting framework for organic wine. This is a sec…
Prevalence of Wine Intolerance
2012
Background Wine is an ancient food product, ubiquitous across cultures all over the world. Its effects on health have been extensively studied, yet there have been only a few case reports of wine intolerance or wine allergy. We studied the prevalence of self-reported wine intolerance in the adult population of Mainz, Germany.
Life Cycle Assessment in the Wine Sector
2015
Currently, stakeholders’ increasing attention to quality is driving the wine sector to rethink and change its own production processes. Amongst product quality dimensions, the environment is gaining ever-growing attention at various levels of policy-making and business. Given its soundness, the use of Life Cycle Assessment (LCA) has become widespread in many application contexts. Apart from applications for communication purposes, LCA has also been used in the wine sector to highlight environmental hot spots in supply chains, to compare farming practices and to detect improvement options, inter alia. Case studies whose focus is the wine industry abound in high quality publications. This Cha…