Impact of Yeast Present During Pre-fermentation Cold Maceration on Pinot Noir Wine Aroma PDF Download

Author: Harper L. Hall
Publisher:
ISBN:
Category : Pinot noir (Wine)
Languages : en
Pages : 72

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Book Description
This research investigated yeast populations and diversity during pre-fermentation cold maceration and alcoholic fermentation of Vitis vinifera L. cv. Pinot noir grapes from a commercial vineyard (Dayton, OR). Fermentations were conducted at the Oregon State University research winery in 100 L tanks while grapes from the same vineyard lot were fermented at a commercial winery. Samples were taken daily during pre-fermentation maceration (9°C) and alcoholic fermentation (27°C) and plated on WL and lysine media to determine Saccharomyces and non-Saccharomyces populations and diversity. Total non-Saccharomyces populations increased from 1 x 103 cfu/mL to 1 x 105 cfu/mL during pre-fermentation cold maceration and reached a maximum of 1 x 107 cfu/mL during alcoholic fermentation. Thirteen distinct yeast species were tentatively identified based on appearance on WL media and were initially screened for [beta]-glucosidase activity using 4-methyllumbelliferyl-[beta]-D-gluconopyranoside (4-MUG) plates. The identity of the isolates screening positive for [beta]-glucosidase activity was determined by sequence analysis of the D1/D2 domain of the 26S rDNA gene. The five isolates identified were Metschnikowia pulcherrima, Hanseniaspora uvarum, Kluveromyces thermotolerans, and two Saccharomyces cerevisiae isolates. [beta]-glucosidase activity was further characterized and quantified using a liquid media representing grape must conditions (pH 3.5, 20° Brix) at two temperatures (25°C and 8°C). While increasing sugar concentration suppressed the [beta]-glucosidase activity of H. uvarum ( -99%), [beta]-glucosidase activity still remained relatively high for M. pulcherrima, S. cerevisiae isolate 1, and S. cerevisiae isolate 2. At 8°C, [beta]-glucosidase activity was reduced for M. pulcherrima compared to activity at 25°C, but activity increased for K. thermotolerans, S. cerevisiae isolate 1, and S. cerevisiae isolate 2. The yeast isolates possessing [beta]-glucosidase activity were used in fermentations of Vitis vinifera L. cv. Pinot Noir grapes. The grapes were treated with high hydrostatic pressure (HHP) to inactivate naturally occurring yeast and bacteria. All yeast isolates grew during pre-fermentation cold maceration (7 days at 9°C) and populations increased 3 to 4 logs. Following pre-fermentation cold maceration, all ferments were warmed to 27°C and inoculated with S. cerevisiae RC212. Alcoholic fermentations were all complete within eight days and after pressing wines were analyzed for volatile aroma compounds by SPME-GC-MS. The presence of different yeast isolates during pre-fermentation cold maceration resulted in wines with unique aroma profiles. Ethyl ester concentrations were highest in the wine that did not undergo a pre-fermentation cold maceration, while concentrations of branch-chained esters were higher in the treatments with yeast present during pre-fermentation cold maceration. Pre-fermentation cold maceration with yeast isolates demonstrating [beta]-glucosidase did not affect the concentration of [beta]-damascenone or [beta]-ionone. Wines that had undergone pre-fermentation cold maceration with S. cerevisiae isolate 1, S. cerevisiae isolate 2, and a combination of all isolates resulted in over twice the concentration of [beta]-citronellol over wines that did not undergo a pre-fermentation cold maceration.

Author: Diana Hawkins
Publisher:
ISBN:
Category : Pinot noir (Wine)
Languages : en
Pages : 75

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Book Description
Recent studies have suggested that yeast and other micro organisms may contribute to a wine’s regional distinctiveness. This study represents the first attempt to experimentally test how yeast communities, consisting of multiple isolates and species, contribute to regional wine attributes in a controlled environment. It sought to explore the following questions using New Zealand Pinot Noir as a medium: • Are yeast communities present in the early stages of uninoculated Pinot Noir fermentations regionally distinct in New Zealand? • Do these yeast communities – including non-Saccharomyces species – modulate wine aroma and/or fermentation kinetics in a regionally distinct manner? • Is there a community effect on fermentation kinetics and/or wine aroma? New methodologies for preparing a mixed species inoculum from regional yeast communities in a repeatable manner were optimised. Synthetic yeast communities comprised of natural isolates were successfully collated for 17 vineyard sites across Martinborough, Marlborough and Central Otago in New Zealand. This allowed community contribution to regional character to be explored in a controlled setting for the first time. The species present during the early stages of uninoculated New Zealand Pinot Noir fermentations were identified; however, we were unable to reject the null hypothesis of no difference in species composition between the three geographic regions since regional differences were not found in the types of species present during the early stages of fermentation. Wines were produced using these yeast communities and 28 yeast-derived aroma compounds were measured via Headspace Solid-Phase Dynamic Extraction Coupled with Gas Chromatography-Mass Spectrometry. Yeast community composition was found to have a significant impact on wine sensory attributes and fermentation kinetic variables. The region the communities were from was also found to have a significant impact on wine sensory attributes; however, the impact on fermentation kinetics was mixed. These results allowed us to reject the two remaining null hypotheses and accept the alternative hypotheses that yeast communities modulate wine aroma in a regionally distinct manner; and that the composition of these communities also modulates wine aroma and fermentation kinetics. This suggests that there is a microbial component to regional character for New Zealand Pinot Noir.

Author: Ronald S. Jackson
Publisher: Academic Press
ISBN: 0128165375
Category : Technology & Engineering
Languages : en
Pages : 1032

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Book Description
Wine Science: Principles and Applications, Fifth Edition, delivers in-depth information and expertise in a single, science-focused volume, including all the complexities and nuances of creating a quality wine product. From variety, to the chemistry that transforms grape to fruit to wine, the book presents sections on the most important information regarding wine laws, authentication, the latest technology used in wine production, and expert-insights into the sensory appreciation of wine and its implications in health. This book is ideal for anyone seeking to understand the science that produces quality wines of every type. Presents thorough explanations of viticulture and winemaking principles from grape to taste bud Addresses historical developments in wine production, notably sparkling wines Provides techniques in grapevine breeding, notably CRISPR Compares production methods in a framework that provides insights into the advantages and disadvantages of each

Author: David G. Takush
Publisher:
ISBN:
Category : Hydrostatic pressure
Languages : en
Pages : 216

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Book Description
The impact of yeast on the aroma and flavor of Vitis vinifera L. cv. 'Pinot Noir' wine was investigated. Due to the presence of naturally occurring yeast and bacteria on grapes and wine equipment, and the influence these microorganisms have on wine, a means of eliminating microorganisms from grape must was explored. High Hydrostatic Pressure (HHP) processing was investigated as a means of inactivating wine microorganisms in grape must without impacting organoleptic properties. Table grape must adjusted to 23°Brix was inoculated with wine-relevant yeast and bacteria and treated for 5 and 10 minutes at 551MPa. At both 5 and 10 minutes of pressure treatment all microorganisms were reduced to below detectable numbers. Next, wine was produced from HHP treated Pinot Noir grapes and the impact of HHP on the sensory properties of the wine was investigated. Descriptive analysis of the wines using a trained panel showed minimal significant differences between wines produced from HHP treated and untreated grape must. Chemical analysis showed no significant differences in color; however, there was a 70% increase in total phenolics in the wine produced from HHP treated must. Because the sensory effects of HHP treatment on grape must appeared to be minimal, the impact of specific yeast on Pinot Noir wine was investigated. HHP treated must was fermented in sterilized red wine micro-fermentors. The yeast strains and species studied were EC1118, RC212, Assmanshausen (AMH) (Lallemand, Montréal, Canada), MERIT.ferm, and Symphony (a blend of MERIT.ferm and Kluyveromyces thermotolerans) (Chr. Hansen, Hørsholm, Denmark). All Saccharomyces yeast strains were inoculated at approximately 106cfu/mL while the non-Saccharomyces yeast was inoculated at approximately 105cfu/mL. Each yeast strain was inoculated in triplicate, and a total of fifteen micro-fermentors, each containing 2.75kg of HHP treated grape must, were used. Fermentation profiles were similar between yeast strains with minimal variability between replicates. However, AMH replicates finished fermentation 24 hours after other yeast strains. After fermentation, analysis showed a significant difference in color at 520nm between the AMH and EC1118 wines. There were no other significant color differences between wines. Descriptive analysis with a trained panel indicated that yeast strain had a significant effect on the sensory profile of Pinot Noir wine. Significant sensory attributes included overall fruity aroma, red fruit aroma, dark fruit aroma, and overall fruit flavor, among others. Principle Component Analysis results showed EC1118 and RC212 trending toward high overall aroma intensities and dark fruit and jammy characteristics. MERIT.ferm also produced wines with high aroma intensities; however, they trended towards red fruit and floral characteristics. The wines produced from AMH and Symphony yeasts were not distinct and resulted in low aroma and flavor intensities in several descriptor categories. The results show that HHP processing is a viable means of inactivating microorganisms from grape must without causing large alterations in the final aroma and flavor profile of wine. The data also demonstrates the feasibility of utilizing HHP processing in conjunction with autoclavable micro-fermentors to conduct experimental red wine fermentations without the influence of native yeast and bacteria. The sensory data from yeast strain trials indicate that yeast can have a significant impact on Pinot Noir wine aroma. This data could help improve control of wine aroma profiles and help improve wine quality in the Pinot Noir industry. However, more research is needed to profile a larger array of oenological yeast strains, including non-Saccharomyces species, and to examine the effects of co-inoculation.

Author: Antonio Morata
Publisher: MDPI
ISBN: 3039215582
Category : Science
Languages : en
Pages : 218

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Book Description
From the beginning of this century, non-Saccharomyces yeasts have taken increased relevance in wine processing. Several biotechnological companies now produce non-Saccharomyces yeasts at an industrial level to improve aroma or flavor, stabilize wine, produce biological acidification, or conversely metabolize malic acid. Species like Torulaspora delbrueckii, Metschnikowia pulcherrima, Kloeckera apiculata, Lachancea thermotolerans, Schizosaccharomyces pombe, and several others are common due to the technological applications they have in sensory quality but also in wine ageing and stabilization. Moreover, spoilage non-Saccharomyces yeasts like Brettanomyces bruxellensis, Saccharomycodes ludwigii, and Zygosacharomyces bailii are becoming important because of the alterations they are able to produce in high-quality wines. New strategies to control these defective yeasts have been developed to control them without affecting sensory quality. The knowledge of the physiology, ecology, biochemistry, and metabolomics of these yeasts can help to better use them in controlling traditional problems such as low fermentative power, excessive volatile acidity, low implantation under enological conditions, and sensibility to antimicrobial compounds like sulfites traditionally used in wine processing. This Special Issue intends to compile current research and revised information on non-Saccharomyces yeasts with enological applications to facilitate the use and the understanding of this biotechnological tool. In 1 year this SI has globally more than 15kdownloads and produced more than 30 citations.

Author: Andrew G. Reynolds
Publisher: Woodhead Publishing
ISBN: 0081020686
Category : Technology & Engineering
Languages : en
Pages : 824

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Book Description
Managing Wine Quality, Volume 1: Viticulture and Wine Quality, Second Edition, reviews our current understanding of wine aroma, color, taste and mouthfeel. In addition, it focuses on the measurement of grape and wine properties, the instrumental analysis of sensory evaluation, and wine authenticity and traceability. The effects of viticulture technologies on grape composition and wine quality attributes are also included, with sections on viticultural and vineyard management practices, fungal contaminants, grape processing equipment, and grape harvesting methods for both red and white wines. In addition, there is coverage on the potential impacts of global warming on wine quality. With a focus on recent studies, advanced methods, and a look to future technologies, this fully updated edition is an essential reference for anyone involved in viticulture and oenology who wants to explore new methods, understand different approaches, and refine existing practices. - Reviews our current understanding of wine aroma, color, taste and mouthfeel - Details the measurement of grape and wine properties through instrumental analysis, must and wine, and sensory evaluation - Examines viticulture and vineyard management practices, fungal contaminants and processing equipment

Author: Harald Claus
Publisher: MDPI
ISBN: 3038976741
Category : Science
Languages : en
Pages : 176

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Book Description
Wineries are facing new challenges due to actual market demands for the creation of products exhibiting more particular flavors. In addition, climate change has lead to the requirement for grape varieties with specific features, such as convenient maturation times, enhanced tolerance towards dryness, osmotic stress, and resistance against plant-pathogens. The next generation of yeast starter cultures should produce wines with an appealing sensory profile and less alcohol. This Special Issue comprises actual studies addressing some of the problems and solutions for the environmental, technical, and consumer challenges of wine making today: Development of sophisticated mass spectroscopic methods enable the identification of the major metabolite spectrum of grapes/wine and deliver detailed insights in terroir and yeast-specific traits;Knowledge of the origin and reactions of reductive sulphur compounds facilitates the avoidance of unpleasant wine odors;Innovative physical–chemical treatments support effective and sustainable color extraction from red grape varieties;Enological enzymes from yeasts used directly or in the form of starter cultures are promising tools to increase the juice yields, color intensity, and aroma of wine;Natural and artificial Saccharomyces hybrids as well as collections of adapted wild isolates from various ecological niches will extend winemakers repertoire, allowing individual fermentations;Exact process control of wine fermentations by convenient computer programs will guarantee consistently high product quality.

Author: Diane Marie Schmitt
Publisher:
ISBN:
Category :
Languages : en
Pages : 141

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Book Description
The aroma profiles of Riesling, Gewürztraminer, and Traminette grapes are largely derived from monoterpenes found in grape pulp and skin. To optimize the extraction of monoterpenes and other volatile compounds, a winemaking technique called pre-fermentation cold soak (CS) is sometimes used. Unfortunately, CS may also allow for the extraction of undesirable bitter compounds, including monomeric phenolics. To address this concern, monomeric phenolic concentrations were measured in wines produced with varying CS durations. Among the compounds analyzed, (+)-catechin and ( - )-epicatechin were most affected by CS duration. Because total monomeric phenolic concentrations tended to increase with increasing CS duration, wine bitterness intensity was quantified by a trained panel. Sensory evaluation results, however, suggest that CS duration and bitterness intensity are not directly related. Following the CS study, detection thresholds of (+)-catechin and ( - )-epicatechin in model and commercial wines were determined in order to learn more about the contributions of these compounds to wine sensory characteristics. (+)-Catechin detection thresholds in model and commercial wines were 205 and 278 ppm, respectively. In contrast, the detection thresholds of ( - )epicatechin were not found for the concentrations tested which went up to 501ppm. Threshold testing was selected as a starting point to understand how individuals perceive these compounds at sub- and suprathreshold levels. CS and other processing conditions can lead to color compound extraction or must oxidation, resulting in darker colored wines and potentially increasing bitterness intensity. The presence of an association between darker white wine color and bitterness intensity was investigated by having a panel of wine professionals rate the bitterness of color-modified white wine samples. The results did not indicate that wine professionals associate darker white wine color with bitterness. A final study investigated the possibility of differentiating Riesling clones through the analysis of juice monomeric phenolic and tannin profiles. The results did not show significant differences in the monomeric phenolic and tannin profiles among the clones analyzed. However, preliminary sensory results suggest that wine professionals can differentiate among monoclonal Riesling wines. If true, it may be possible to differentiate among Riesling clones through the analysis of other volatile and non-volatile compounds.

Author: Santiago Benito
Publisher: MDPI
ISBN: 3039289470
Category : Science
Languages : en
Pages : 220

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Book Description
During the last few years, industrial fermentation technologies have advanced in order to improve the quality of the final product. Some examples of those modern technologies are the biotechnology developments of microbial materials, such as Saccharomyces and non-Saccharomyces yeasts or lactic bacteria from different genera. Other technologies are related to the use of additives and adjuvants, such as nutrients, enzymes, fining agents, or preservatives and their management, which directly influence the quality and reduce the risks in final fermentation products. Other technologies are based on the management of thermal treatments, filtrations, pressure applications, ultrasounds, UV, and so on, which have also led to improvements in fermentation quality in recent years. The aim of the issue is to study new technologies able to improve the quality parameters of fermentation products, such as aroma, color, turbidity, acidity, or any other parameters related to improving sensory perception by the consumers. Food safety parameters are also included.

Author: Karna Lyn Sacchi
Publisher:
ISBN:
Category :
Languages : en
Pages : 224

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