scholarly journals The effect of grape juice dilution on oenological fermentation

2020 ◽  
Author(s):  
Jennifer Margaret Gardner ◽  
Michelle Elisabeth Walker ◽  
Paul Kenneth Boss ◽  
Vladimir Jiranek
Keyword(s):  
Alcoholic Fermentation ◽  
Grape Juice ◽  
Malolactic Fermentation ◽  
Isoamyl Acetate ◽  
List Type ◽  
Water Addition ◽  
Wine Flavour ◽  
Wine Volatiles ◽  
The Impact ◽  
Complex Organic

AbstractThe impact of water addition to grape juice in winemaking, on both alcoholic and malolactic fermentation duration and outcome has been examined using commercial wine yeasts, Lalvin EC1118™ and Lalvin R2™ and malolactic bacteria Lalvin VP41™. As expected, dilution with water did not impede fermentation, instead resulted in shortened duration, or in the case of malolactic fermentation enabled completion in these conditions. Addition of complex organic nutrient further shortened alcoholic fermentation by Lalvin R2™ and in some conditions also reduced the duration of malolactic fermentation. In general, volatile compounds and some major yeast metabolites were present at lower concentrations at the end of fermentation where juices were diluted and the addition of organic complex nutrient also influenced the concentration of some compounds in wine. These findings are significant to commercial winemaking, highlighting that winemakers should consider potential impacts of juice dilution on processing efficiencies along with wine flavour and aroma.Highlights: Gardner et al. The effect of grape juice dilution on fermentationGrape juice dilution shortened both alcoholic and malolactic fermentationIn some conditions addition of commercial nutrient decreased fermentation durationIn general wine volatiles decrease with grape juice dilutionIsoamyl acetate can be decreased in wine by grape juice dilution

scholarly journals Impact of Botrytis cinerea Contamination on the Characteristics and Foamability of Yeast Macromolecules Released during the Alcoholic Fermentation of a Model Grape Juice

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 472
Author(s):  
Richard Marchal ◽  
Thomas Salmon ◽  
Ramon Gonzalez ◽  
Belinda Kemp ◽  
Céline Vrigneau ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Alcoholic Fermentation ◽  
Periodic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Grape Juice ◽  
Size Exclusion ◽  
Periodic Acid Schiff ◽  
Exclusion Chromatography ◽  
The Impact

Botrytis cinerea is a fungal pathogen responsible for the decrease in foamability of sparkling wines. The proteolysis of must proteins originating from botrytized grapes is well known, but far less information is available concerning the effect of grape juice contamination by Botrytis. The impact from Botrytis on the biochemical and physico-chemical characteristics of proteins released from Saccharomyces during alcoholic fermentation remains elusive. To address this lack of knowledge, a model grape juice was inoculated with three enological yeasts with or without the Botrytis culture supernatant. Size exclusion chromatography coupled to multi-angle light scattering (SEC-MALLS) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) techniques (AgNO3 and periodic acid Schiff staining) was used in the study. When Botrytis enzymes were present, a significant degradation of the higher and medium MW molecules released by Saccharomyces was observed during alcoholic fermentation whilst the lower MW fraction increased. For the three yeast strains studied, the results clearly showed a strong decrease in the wine foamability when synthetic musts were inoculated with 5% (v/v) of Botrytis culture due to fungus proteases.

scholarly journals The Impact of Chitosan on the Chemical Composition of Wines Fermented with Schizosaccharomyces pombe and Saccharomyces cerevisiae

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1423
Author(s):  
Stefano Scansani ◽  
Doris Rauhut ◽  
Silvia Brezina ◽  
Heike Semmler ◽  
Santiago Benito
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chemical Composition ◽  
Schizosaccharomyces Pombe ◽  
Alcoholic Fermentation ◽  
Yeast Species ◽  
Grape Juice ◽  
Ethyl Esters ◽  
High Concentration ◽  
Wine Quality ◽  
The Impact

This study investigates the influence of the antimicrobial agent chitosan on a selected Schizosaccharomyces pombe strain during the alcoholic fermentation of ultra-pasteurized grape juice with a high concentration of malic acid. It also studies a selected Saccharomyces cerevisiae strain as a control. The study examines several parameters relating to wine quality, including volatile and non-volatile compounds. The principal aim of the study is to test the influence of chitosan on the final chemical composition of the wine during alcoholic fermentation, and to compare the two studied fermentative yeasts between them. The results show that chitosan influences the final concentration of acetic acid, ethanol, glycerol, acetaldehyde, pyruvic acid, α-ketoglutarate, higher alcohols, acetate esters, ethyl esters, and fatty acids, depending on the yeast species.

scholarly journals Impact of Lachancea thermotolerans strain and lactic acid concentration on Oenococcus oeni and malolactic fermentation in wine

OENO One ◽  
2021 ◽  
Vol 55 (2) ◽  
pp. 365-380
Author(s):  
Emma C. Snyder ◽  
Vladimir Jiranek ◽  
Ana Hranilovic
Keyword(s):  
Lactic Acid ◽  
Alcoholic Fermentation ◽  
Lactic Acid Production ◽  
Malolactic Fermentation ◽  
Oenococcus Oeni ◽  
Inhibitory Effect ◽  
Sequential Inoculation ◽  
The Impact ◽  
Lachancea Thermotolerans

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. 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 lactic acid producing strain enabled successful MLF, even when this failed in the S. cerevisiae treatment, with dramatically quicker malic acid depletion in O. oeni co-inoculation than in sequential inoculation. In contrast, a high lactic acid producing strain inhibited MLF irrespective of the O. oeni inoculation strategy. In a follow-up experiment, increasing concentrations of exogenously added lactic acid slowed MLF and reduced O. oeni growth across different matrices, with 6 g/L of lactic acid completely inhibiting MLF. The results confirm the inhibitory effect of lactic acid on O. oeni while highlighting the potential of some L. thermotolerans strains to promote MLF and the others to inhibit it.

scholarly journals The non-Saccharomyces yeast Pichia kluyveri for the production of aromatic volatile compounds in alcoholic fermentation

2020 ◽  
Author(s):  
Andrés Méndez-Zamora ◽  
Daniel Oswaldo Gutiérrez-Avendaño ◽  
Melchor Arellano-Plaza ◽  
Francisco Javier De la Torre González ◽  
Iliana Barrera-Martínez ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Alcoholic Fermentation ◽  
Culture Media ◽  
Principal Component ◽  
Isoamyl Acetate ◽  
Alcoholic Beverages ◽  
Agave Tequilana ◽  
Pichia Kluyveri ◽  
The Impact ◽  
Saccharomyces Yeasts

ABSTRACT Alcoholic fermentation is influenced by yeast strain, culture media, substrate concentration, and fermentation conditions, which contribute to taste and aroma. Some non-Saccharomyces yeasts are recognized as volatile compounds producers that enrich aromatic profile of alcoholic beverages. In this work, 21 strains of Pichia kluyveri, isolated from different fermentative processes and regions were evaluated. A principal component analysis (PCA) showed statistical differences between strains mainly associated with the variety and concentration of the compounds produced. From the PCA, two strains (PK1 and PK8) with the best volatile compound's production were selected to evaluate the impact of culture media (M12 medium and Agave tequilana juice), stirring speeds (100 and 250 rpm) and temperatures (20, 25 and 30°C). Increased esters production was observed at 250 rpm. Greatest effect in alcohols and esters production was found with A. tequilana, identifying PK1 as higher alcohols producer, and PK8 as better esters producer. Regarding temperature, PK1 increased ester production with decreased fermentation temperature. PK8 presented maximum levels of ethyl acetate and ethyl dodecanoate at 20°C, finally isoamyl acetate increased its production at 30°C. Therefore, P. kluyveri strains are of great interest to produce different aromatic profiles which are affected by factors including medium, agitation and temperature.

scholarly journals Effect of sulfite addition and pied de cuve inoculation on the microbial communities and sensory profiles of Chardonnay wines: dominance of indigenous Saccharomyces uvarum at a commercial winery

2019 ◽  
Vol 19 (5) ◽  
Author(s):  
Sydney C Morgan ◽  
Garrett C McCarthy ◽  
Brittany S Watters ◽  
Mansak Tantikachornkiat ◽  
Ieva Zigg ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Alcoholic Fermentation ◽  
Indigenous Population ◽  
Microbial Consortium ◽  
Grape Juice ◽  
Malolactic Fermentation ◽  
Fungal Communities ◽  
Saccharomyces Uvarum ◽  
Culture Independent ◽  
Sensory Profiles

ABSTRACT The microbial consortium of wine fermentations is highly dependent upon winemaking decisions made at crush, including the decision to inoculate and the decision to add sulfur dioxide (SO2) to the must. To investigate this, Chardonnay grape juice was subjected to two inoculation treatments (uninoculated and pied de cuve inoculation) as well as two SO2 addition concentrations (0 and 40 mg/L). The bacterial communities, fungal communities and Saccharomyces populations were monitored throughout fermentation using culture-dependent and culture-independent techniques. After fermentation, the wines were evaluated by a panel of experts. When no SO2 was added, the wines underwent alcoholic fermentation and malolactic fermentation simultaneously. Tatumella bacteria were present in significant numbers, but only in the fermentations to which no SO2 was added, and were likely responsible for the malolactic fermentation observed in these treatments. All fermentations were dominated by a genetically diverse indigenous population of Saccharomyces uvarum, the highest diversity of S. uvarum strains to be identified to date; 150 unique strains were identified, with differences in strain composition as a result of SO2 addition. This is the first report of indigenous S. uvarum strains dominating and completing fermentations at a commercial winery in North America.

scholarly journals PTR-ToF-MS for the Online Monitoring of Alcoholic Fermentation in Wine: Assessment of VOCs Variability Associated with Different Combinations of Saccharomyces/Non-Saccharomyces as a Case-Study

Fermentation ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 55 ◽  
Author(s):  
Carmen Berbegal ◽  
Iuliia Khomenko ◽  
Pasquale Russo ◽  
Giuseppe Spano ◽  
Mariagiovanna Fragasso ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Alcoholic Fermentation ◽  
Grape Juice ◽  
Starter Cultures ◽  
Mass Analyzer ◽  
Technological Parameters ◽  
Wine Quality ◽  
The Impact ◽  
Tof Ms

The management of the alcoholic fermentation (AF) in wine is crucial to shaping product quality. Numerous variables (e.g., grape varieties, yeast species/strains, technological parameters) can affect the performances of this fermentative bioprocess. The fact that these variables are often interdependent, with a high degree of interaction, leads to a huge ‘oenological space’ associated with AF that scientists and professionals have explored to obtain the desired quality standards in wine and to promote innovation. This challenge explains the high interest in approaches tested to monitor this bioprocess including those using volatile organic compounds (VOCs) as target molecules. Among direct injection mass spectrometry approaches, no study has proposed an untargeted online investigation of the diversity of volatiles associated with the wine headspace. This communication proposed the first application of proton-transfer reaction-mass spectrometry coupled to a time-of-flight mass analyzer (PTR-ToF-MS) to follow the progress of AF and evaluate the impact of the different variables of wine quality. As a case study, the assessment of VOC variability associated with different combinations of Saccharomyces/non-Saccharomyces was selected. The different combinations of microbial resources in wine are among the main factors susceptible to influencing the content of VOCs associated with the wine headspaces. In particular, this investigation explored the effect of multiple combinations of two Saccharomyces strains and two non-Saccharomyces strains (belonging to the species Metschnikowia pulcherrima and Torulaspora delbrueckii) on the content of VOCs in wine, inoculated both in commercial grape juice and fresh grape must. The results demonstrated the possible exploitation of non-invasive PTR-ToF-MS monitoring to explore, using VOCs as biomarkers, (i) the huge number of variables influencing AF in wine, and (ii) applications of single/mixed starter cultures in wine. Reported preliminary findings underlined the presence of different behaviors on grape juice and on must, respectively, and confirmed differences among the single yeast strains ‘volatomes’. It was one of the first studies to include the simultaneous inoculation on two non-Saccharomyces species together with a S. cerevisiae strain in terms of VOC contribution. Among the other outcomes, evidence suggests that the addition of M. pulcherrima to the coupled S. cerevisiae/T. delbrueckii can modify the global release of volatiles as a function of the characteristics of the fermented matrix.

scholarly journals Using Satellite Data for CBRN (Chemical, Biological, Radiological, and Nuclear) Threat Detection, Monitoring, and Modelling

2021 ◽  
Author(s):  
Gary Sutlieff ◽  
Lucy Berthoud ◽  
Mark Stinchcombe
Keyword(s):  
Satellite Data ◽  
Meteorological Data ◽  
Atmospheric Composition ◽  
Chemical Detection ◽  
List Type ◽  
Data Types ◽  
Wide Range ◽  
Future Technologies ◽  
The Impact ◽  
Near Future

Abstract CBRN (Chemical, Biological, Radiological, and Nuclear) threats are becoming more prevalent, as more entities gain access to modern weapons and industrial technologies and chemicals. This has produced a need for improvements to modelling, detection, and monitoring of these events. While there are currently no dedicated satellites for CBRN purposes, there are a wide range of possibilities for satellite data to contribute to this field, from atmospheric composition and chemical detection to cloud cover, land mapping, and surface property measurements. This study looks at currently available satellite data, including meteorological data such as wind and cloud profiles, surface properties like temperature and humidity, chemical detection, and sounding. Results of this survey revealed several gaps in the available data, particularly concerning biological and radiological detection. The results also suggest that publicly available satellite data largely does not meet the requirements of spatial resolution, coverage, and latency that CBRN detection requires, outside of providing terrain use and building height data for constructing models. Lastly, the study evaluates upcoming instruments, platforms, and satellite technologies to gauge the impact these developments will have in the near future. Improvements in spatial and temporal resolution as well as latency are already becoming possible, and new instruments will fill in the gaps in detection by imaging a wider range of chemicals and other agents and by collecting new data types. This study shows that with developments coming within the next decade, satellites should begin to provide valuable augmentations to CBRN event detection and monitoring. Article Highlights There is a wide range of existing satellite data in fields that are of interest to CBRN detection and monitoring. The data is mostly of insufficient quality (resolution or latency) for the demanding requirements of CBRN modelling for incident control. Future technologies and platforms will improve resolution and latency, making satellite data more viable in the CBRN management field

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