Growth In Wine Research Articles

Why types of operations, trade associations, and production trends matter in the geographic branding of an emerging industry

ABSTRACT Geographic branding has become an important strategy for economic actors to differentiate their products. While studies have examined geographic branding in well-established industries, less is known about the factors that lead to the adoption of geographic branding innovations in emerging industries. Results from a 2011 mail survey of Pennsylvania winemakers (N = 71, response rate: 50%) indicate that winery operation type (grape grower or wine-only), growth in wine and/or grape production, and trade association membership influence the extent to which geographic branding is adopted and in what forms (regional or state-based) it is used. Winemakers also identified challenges that they believe limit the economic growth of the industry. Findings shed light on the opportunities and limitations of geographical branding and its impacts on regional development.

New challenges in the application of biocompatible silver nanoparticles in enology: Antimicrobial capacity, digestibility and potential cytotoxicity

In the search for new substitutes to the use of sulfur dioxide (SO2 ) in oenology, a new line of research based on nanotechnology has been launched. Within this line, this paper evaluates the suitability of two new biocompatible silver nanoparticles (Ag-NPs) to control microbial growth in wine as well as their stability and potential risks at intestinal level. Antimicrobial activities against spoilage wine microorganisms were carried out in both culture media and wines. In addition, in vitro simulations (static and dynamic) were conducted to monitor the passage of Ag-NPs through the buco-gastrointestinal tract and also to assess their effects on the gut microbiota and intestinal epithelial cells. Both Ag-NPs proved to be highly efficient for the control of wine undesirable bacteria in culture media and microvinification assays, and to a lesser extent, for reducing Brettanomyces populations in wine. Furthermore, undigested Ag-NPs as their corresponding digests after gastrointestinal simulation were not toxic to intestinal microbiota either epithelial cells, at least at the conditions used in these experiments.

Impact of Australian Dekkera bruxellensis strains grown under oxygen-limited conditions on model wine composition and aroma

Spoilage of red wine by the yeast species Dekkera bruxellensis is a common problem for the global wine industry. When conditions are conducive for growth of these yeasts in wine, they efficiently convert non-volatile hydroxycinnamic acids into aroma-active ethylphenols, thereby reducing the quality of the wine. It has been demonstrated previously that dissolved oxygen is a key factor which stimulates D. bruxellensis growth in wine. We demonstrate that whereas the presence of oxygen accelerates the growth of this species, oxygen-limited conditions favour 4-ethylphenol production. Consequently, we evaluated wine spoilage potential of three D. bruxellensis strains (AWRI1499, AWRI1608 and AWRI1613) under oxygen-limited conditions. Each strain was cultured in a chemically-defined wine medium and the fermentation products were analysed using HPLC and HS-SPME–GC/MS. The strains displayed different growth characteristics but were equally capable of producing ethylphenols. On the other hand, significant differences were observed for 18 of the remaining 33 metabolites analysed and duo-trio sensory analysis indicated significant aroma differences between wines inoculated with AWRI1499 and AWRI1613. When these wines were spiked with low concentrations of 4-ethylphenol and 4-ethylguaiacol, no sensorial differences could be perceived. Together these data suggest that the three predominant D. bruxellensis strains previously isolated during a large survey of Australian wineries do not differ substantively in their capacity to grow in, and spoil, a model wine medium.

Cytofluorometric detection of wine lactic acid bacteria: application of malolactic fermentation to the monitoring

In this study we report for the first time a rapid, efficient and cost-effective method for the enumeration of lactic acid bacteria (LAB) in wine. Indeed, up to now, detection of LAB in wine, especially red wine, was not possible. Wines contain debris that cannot be separated from bacteria using flow cytometry (FCM). Furthermore, the dyes tested in previous reports did not allow an efficient staining of bacteria. Using FCM and a combination of BOX/PI dyes, we were able to count bacteria in wines. The study was performed in wine inoculated with Oenococcus oeni (10(6)CFUml(-1)) stained with either FDA or BOX/PI and analyzed by FCM during the malolactic fermentation (MLF). The analysis show a strong correlation between the numbers of BOX/PI-stained cells determined by FCM and the cell numbers determined by plate counts (red wine: R (2)≥0.97, white wine R (2)≥0.965). On the other hand, we found that the enumeration of O. oeni labeled with FDA was only possible in white wine (R (2)≥0.97). Viable yeast and LAB populations can be rapidly discriminated and quantified in simultaneous malolactic-alcoholic wine fermentations using BOX/PI and scatter parameters in a one single measurement. This rapid procedure is therefore a suitable method for monitoring O. oeni populations during winemaking, offers a detection limit of <10(4)CFUml(-1) and can be considered a useful method for investigating the dynamics of microbial growth in wine and applied for microbiological quality control in wineries.

Comparison of near infrared and mid infrared spectroscopy to discriminate between wines produced by different Oenococcus Oeni strains after malolactic fermentation: A feasibility study

The wine industry requires rapid, comprehensive methods and techniques to answer the new challenges driven by the market demands. Recent advances in spectroscopy technologies have brought about a revolution in the manner in which biological systems are visualised and analysed. The measurement of numerous small molecules (metabolites) metabolised by microorganisms during growth in wine, will benefit from techniques that require minimal sample preparation, permit the automatic analysis of many samples with negligible reagent costs, allow their rapid characterization against a stable database, and are easy to use. With recent developments in analytical instrumentation, these requirements are being fulfilled by vibrational spectroscopic methods, often referred to as “whole-organism fingerprinting” and more recently “metabolic fingerprinting”. The objective of this study was to evaluate and compare the use of near (NIR) and mid infrared (MIR) spectroscopy as rapid methods to distinguish red and white wines obtained by using different strains of Oenococcus oeni following malolactic fermentation. Using NIR and MIR wines produced with different O. oeni strains could be distinguished both in red and white wines yielding correct classification rates between 67 and 100% depending on the strain.

Effectiveness of dimethlydicarbonate to prevent Brettanomyces bruxellensis growth in wine

The aim of this study was to investigate the anti-microbial properties of the dimethyldicarbonate (DMDC) towards the wine spoilage yeast Brettanomyces bruxellensis at different winemaking stages. DMDC anti-microbial activity was estimated in red must for diverse wine microorganisms including different strains of B. bruxellensis. DMDC effect before alcoholic fermentation, before malolactic fermentation, and in finished wine were investigated. DMDC was also tested on lees. Microbial monitoring was done by epifluorescence observation and plate numeration. The identification of yeast species and the specific detection of B. bruxellensis were performed with molecular tools. DMDC stopped B. bruxellensis growth at different winemaking stages. But it could also act on fermenting species like Saccharomyces cerevisiae and Oenococcus oeni. Therefore, its use before the end of fermentations should be avoided. On the other hand, the DMDC action was shown to be transitory. Therefore, single addition during ageing could be insufficient. Finally, DMDC could be used just before bottling as an ultimate anti-microbial tool.

Real-time PCR for characterizing the stress response of Oenococcus oeni in a wine-like medium

The tolerance of the lactic acid bacterium Oenococcus oeni to hostile wine conditions is essential for the success of malolactic fermentation (MLF). In this study, reverse transcription quantitative PCR (RT-qPCR) was used to quantify the transcript level of 13 genes that could play a role in adaptation of O. oeni in wine. To optimize survival and growth in wine, cells were adapted during growth at low pH (3.5) prior to inoculation into wine. The level of gene expression was analyzed after growth at pH 3.5 in a rich medium and during MLF in a wine-like medium. RT-qPCR analyses exhibited different expression ratios of stress genes. The data obtained showed that determination of mRNA levels could constitute a new approach to studying the stress response of O. oeni after adaptation at low pH and during growth in a wine-like medium.

Article

Expression of Oenococcus oeni clpP-clpL locus in response to environmental conditions. The Oenococcus oeni lactic acid bacterium, mainly responsible for malolactic fermentation during winemaking processes, is confronted with various stresses including the presence of ethanol or low pH. The tolerance of this bacterium to stress is essential for its growth in wine. Comprehension of mechanisms involved in stress response is required for the control of malolactic starters. One of these mechanisms is based on the synthesis of stress proteins. This study deals with clp genes, which were known to play a central role in stress response and also in microbial development. The genome of O. oeni contains two genes surprisingly located in the same locus, encoding ClpP and ClpL proteins. The aim of this work was to characterize the clpP-clpL locus and the transcriptional expression during growth and following stress. In order to quantify the transcript ratios, a quantitative real-time reverse transcription-PCR experiment was set up. Finally, the regulation mechanisms of the O. oeni stress genes were discussed.

Malolactic Fermentation in Wine by Direct Inoculation with Freeze-DriedLeuconostoc oenosCultures

The identification of 850 bacterial isolates collected from French, Portuguese, Italian, and Spanish wines undergoing malolactic fermentation showed that 77% belonged to the species <i>Leuconostoc oenos</i>. Hybridization of total bacterial DNA using phage DNA as probe indicated that 80% of the <i>L. oenos</i> isolates were lysogenic. <i>L. oenos</i> strains were selected for growth in wine with low pH and high ethanol concentration by use of a turbidostat and further screened for their ability to maintain the adaptation to the wine environment during propagation, freezing, and freeze-drying. Several of the selected freeze-dried strains survived 100% the direct inoculation into commercial wines where they started to grow without a lag phase. The immediate survival and the lag phase of the inoculated bacteria strongly influenced the total duration of the malolactic fermentation. Cultures for direct inoculation may substantially improve the management of malolactic fermentation in winemaking.

Properties of Wine Lactic Acid Bacteria: Their Potential Enological Significance

Lactic acid bacteria isolated from Australian red wines were examined for properties of potential enological significance. Some 166 strains were tested. Strains of <i>Leuconostoc oenos</i> were divided into rough and smooth morphotypes on the basis of colony appearance. Rough morphotypes produced cells arranged in long chains and readily grew in wine. Smooth morphotypes produced cells arranged in pairs or short chains, but most of these strains exhibited poor growth in wine. As tested in API 50CH galleries (pH 6.0), strains of <i>L. oenos, Pediococcus parvulus</i>, and several <i>Lactobacillus</i> species exhibited considerable heterogeneity in their abilities to ferment carbohydrates. The fermentation profile of individual strains was altered when the pH was reduced to 4.0. Strains of <i>L. oenos</i> were more tolerant of low pH than those of <i>P. parvulus</i> or <i>Lactobacillus</i> spp. Strains of <i>P. parvulus</i> and <i>Lactobacillus</i> spp. were more tolerant of high concentrations of ethanol and total sulfur dioxide. None of the strains produced extracellular protease. Lipases were produced by several strains of <i>L. oenos</i> and one strain of <i>Lactobacillus</i>. The majority of strains produced esterases.