Antioxidant inactivated yeast: High potential of non-Saccharomyces specific metabolome.

Understanding the contribution of new natural sources of antioxidant compounds to the stability of wines is of great interest in a context of reduction of sulfites. Here, we investigated the antioxidant potential of selected inactivated non-Saccharomyces yeast (INSY) along with related chemical fingerprints, using combined untargeted UHPLC-Q-ToF MS and DPPH analyses. 4 INSY species were compared to a reference inactivated Saccharomyces cerevisiae yeast (ISY) selected for its high antioxidant capacity.

High-Resolution Mass Spectrometry-Based Metabolomics for Increased Grape Juice Metabolite Coverage.

The composition of the juice from grape berries is at the basis of the definition of technological ripeness before harvest, historically evaluated from global sugar and acid contents. If many studies have contributed to the identification of other primary and secondary metabolites in whole berries, deepening knowledge about the chemical composition of the sole flesh of grape berries (i.e.

To each their own: Delving into the vitaminic preferences of non-Saccharomyces wine yeasts.

Considering the growing interest in non-Saccharomyces wine yeasts, and notably in the context of mixed fermentations with S. cerevisiae, understanding their nutritional behaviors is essential to ensure better management of these fermentations. The vitaminic consumption of three non-Saccharomyces yeasts (Starmerella bacillaris, Metschnikowia pulcherrima and Torulaspora delbrueckii) was investigated during their growth in wine-like conditions, providing initial evidence that they consume different vitamers.

Thiamine and Biotin: Relevance in the Production of Volatile and Non-Volatile Compounds during Alcoholic Fermentation in Synthetic Grape Must.

Vitamins are major cofactors to numerous key metabolic pathways in enological yeasts, and both thiamine and biotin, notably, are believed to be essential to yeast fermentation and growth, respectively. In order to further assess and clarify their role in winemaking, and in the resulting wine, alcoholic fermentations of a commercial active dried yeast were conducted in synthetic media containing various concentrations of both vitamins. Growth and fermentation kinetics were monitored and proved the essential character of biotin in yeast growth, and of thiamine in fermentation.

Experimental evolution forcing Oenococcus oeni acid tolerance highlights critical role of the citrate locus.

Oenococcus oeni is the main lactic acid bacterium associated with malolactic fermentation (MLF) of wines. MLF plays an important role in determining the final quality of wines. Nevertheless, due to the stressful conditions inherent to wine and especially acidity, MLF may be delayed.

Complex carbonaceous matter in Tissint martian meteorites give insights into the diversity of organic geochemistry on Mars.

We report a huge organic diversity in the Tissint Mars meteorite and the sampling of several mineralogical lithologies, which revealed that the organic molecules were nonuniformly distributed in functionality and abundance. The range of organics in Tissint meteorite were abundant C aliphatic branched carboxylic acids and aldehydes, olefins, and polyaromatics with and without heteroatoms in a homologous oxidation structural continuum. Organomagnesium compounds were extremely abundant in olivine macrocrystals and in the melt veins, reflecting specific organo-synsthesis processes in close interaction with the magnesium silicates and temperature stresses, as previously observed.

Exploring the unexplored: A characterization of vitamins and vitamers in white grape musts by high-performance liquid chromatography.

Although prime compounds in yeast metabolism, vitamins in oenology have remained mostly unexplored for decades. Here, a premier characterization of the vitamers in white grape musts has been drawn. A RP-HPLC method has therefore been developed for their direct analysis in musts, allowing for the determination of 19 different vitamers from 8 water-soluble vitaminic groups, including thiamine forms T, TMP and TPP, with LODs between 0.

Oxygen management during kombucha production: Roles of the matrix, microbial activity, and process parameters.

Oxygen plays a key role in kombucha production, since the production of main organic acids, acetic and gluconic acids, is performed through acetic acid bacteria's oxidative metabolism. Oxygen consumption during traditional kombucha production was investigated by comparing kombucha to mono and cocultures in sugared tea of microorganisms isolated from kombucha. Two yeasts, Brettanomyces bruxellensis and Hanseniaspora valbyensis and one acetic acid bacterium Acetobacter indonesiensis were used.

Vitamins in wine: Which, what for, and how much?

Vitamins are essential compounds to yeasts, and notably in winemaking contexts. Vitamins are involved in numerous yeast metabolic pathways, including those of amino acids, fatty acids, and alcohols, which suggests their notable implication in fermentation courses, as well as in the development of aromatic compounds in wines. Although they are major components in the course of those microbial processes, their significance and impact have not been extensively studied in the context of winemaking and wine products, as most of the studies focusing on the subject in the past decades have relied on relatively insensitive and imprecise analytical methods.

Exploring the chemical space of white wine antioxidant capacity: A combined DPPH, EPR and FT-ICR-MS study.

The chemical composition and functionality of molecular fractions associated with dry white wines oxidative stability remain poorly understood. In the present study, DPPH assay, electron paramagnetic resonance spectroscopy (EPR) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) were used to explore the chemical diversity associated with the antioxidant capacity (AC) of white wines. AC determined using the DPPH assay and EPR were complementary and enabled differentiation of wine samples into groups with low, medium, and high AC.

Microbiological and technological parameters impacting the chemical composition and sensory quality of kombucha.

Kombucha is a beverage made from sugared tea transformed by yeasts and acetic acid bacteria. Being originally homemade, it has become an industrially produced soft drink whose quality standards are poorly defined and whose production process is still not fully controlled. Based on current knowledge in beverages, links between kombucha's chemical composition and sensorial compounds are drawn.

Unexpected high production of biohydrogen from the endogenous fermentation of grape must deposits.

The aim of this work was to assess the performances of wine byproduct biomass for hydrogen production by dark fermentation. Grape must deposits from two grape varieties (Pinot Gris and Chardonnay) were considered, either with external microbial inoculum or without. We show that grape must residues contain endogenous microflora, well adapted to their environment, which can degrade sugars (initially contained in the biomass) to hydrogen without any nutrient addition.

A First Tentative for Simultaneous Detection of Fungicides in Model and Real Wines by Microwave Sensor Coupled to Molecularly Imprinted Sol-Gel Polymers.

A molecularly imprinted silica (MIS) coupled to a microwave sensor was used to detect three fungicides (iprodione, procymidone and pyrimethanil) present in most French wines. Chemometric methods were applied to interpret the microwave spectra and to correlate microwave signals and fungicide concentrations in a model wine medium, and in white and red Burgundy wines. The developed microwave sensor coupled to an MIS and to its control, a nonimprinted silica (NIS), was successfully applied to detect the three fungicides present in trace levels (ng L) in a model wine.

Regionality in Australian Pinot noir wines: A study on the use of NMR and ICP-MS on commercial wines.

Wine quality and character are defined in part by the terroir in which the grapes are grown. Metabolomic techniques, such as nuclear magnetic resonance (NMR) spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS), are used to characterise wines and to detect wine fraud in other countries but have not been extensively trialled in Australia. This paper describes the use of ICP-MS and NMR to characterise a selection of Pinot noir wines.

Microbial Dynamics between Yeasts and Acetic Acid Bacteria in Kombucha: Impacts on the Chemical Composition of the Beverage.

Kombucha is a traditional low-alcoholic beverage made from sugared tea and transformed by a complex microbial consortium including yeasts and acetic acid bacteria (AAB). To study the microbial interactions and their impact on the chemical composition of the beverage, an experimental design with nine couples associating one yeast strain and one AAB strain isolated from original black tea kombucha was set up. Three yeast strains belonging to the genera , , and and three strains of and species were chosen.

Bio-Protection as an Alternative to Sulphites: Impact on Chemical and Microbial Characteristics of Red Wines.

In wine, one method of limiting the addition of sulphites, a harmful and allergenic agent, is bio-protection. This practice consists of the early addition of microorganisms on grape must before fermentation. Non- yeasts have been proposed as an interesting alternative to sulphite addition.

Wine Yeast Terroir: Separating the Wheat from the Chaff-for an Open Debate.

Wine terroir is characterized by a specific taste and style influenced by the cultivar of the fermented grapes, geographical factors such as the vineyard, mesoclimate, topoclimate, and microclimate, soil geology and pedology, and the agronomic approach used. These characteristics together define the concept of "terroir". Thus, regional distinctive flavors in wine have been the subject of many studies aimed at better understanding the link between the wine and the vineyard.

Antioxidant activity from inactivated yeast: Expanding knowledge beyond the glutathione-related oxidative stability of wine.

Maintaining wine oxidative stability during barrel ageing and shelf life storage remains a challenge. This study evaluated the antioxidant activities of soluble extracts from seven enological yeast derivatives (YDs) with increased glutathione (GSH) enrichment. YDs enriched in GSH appeared on average 3.

Disentangling the effect of host genetics and gut microbiota on resistance to an intestinal parasite.

Resistance to infection is a multifactorial trait, and recent work has suggested that the gut microbiota can also contribute to resistance. Here, we performed a fecal microbiota transplant to disentangle the contribution of the gut microbiota and host genetics as drivers of resistance to the intestinal nematode Heligmosomoides polygyrus. We transplanted the microbiota of a strain of mice (SJL), resistant to H.

Chemical Transfers Occurring Through Biofilm in Different Enological Conditions.

Chardonnay wine malolactic fermentations were carried out to evaluate the chemical transfers occurring at the wood/wine interface in the presence of two different bacterial lifestyles. To do this, was inoculated into must and wine in its planktonic and biofilm lifestyles, whether adhering or not to oak chips, leading to three distinct enological conditions: (i) post-alcoholic fermentation inoculation in wine in the absence of oak chips, (ii) post-alcoholic fermentation inoculation in wine in the presence of oak chips, and (iii) co-inoculation of both and directly in Chardonnay musts in the presence of oak chips. Classical microbiological and physico-chemical parameters analyzed during the fermentation processes confirmed that alcoholic fermentation was completed identically regardless of the enological conditions, and that once had acquired a biofilm lifestyle in the presence or absence of oak, malolactic fermentation occurred faster and with better reproducibility compared to planktonic lifestyles.

Metabolic diversity conveyed by the process leading to glutathione accumulation in inactivated dry yeast: A synthetic media study.

Glutathione-rich inactivated dry yeasts (GSH-IDY) are purported to accumulate glutathione intracellularly and then released into the must. Glutathione is beneficial for wine quality, but research has highlighted that GSH-IDYs have a synergic antioxidant effect similar to that of molecular GSH. Combination of negative mode ultra-high-resolution Fourrier-Transform Ion-Cyclotron-Resonance Mass Spectrometry ((-)FT-ICR-MS), ultra-high-performance liquid chromatography coupled to a Quadrupole-Time of Flight mass spectrometer (UHPLC-Q-ToF-MS) and HPLC/Diode Detector Array (DAD)-Fluorescence spectroscopy was applied to three inactivated dry yeasts soluble fractions, with increasing intracellular glutathione concentration, in order to explore the chemical diversity released in different synthetic media.