Author: Seung Kook ParkPublisher:
ISBN:
Category :
Languages : en
Pages : 280
Book Description
Factors Affecting Formation of Volatile Sulfur Compounds in Wines
Author: Seung Kook ParkImpact of Lees Content, Nitrogen, and Elemental Sulfur on Volatile Sulfur Compound Formation in Vitis Vinifera L Cv 'Pinot Noir' Wine
Author: Daniel N. KraftPublisher:
ISBN:
Category : Grapes
Languages : en
Pages : 125
Book Description
One of the most common problems in wine production is the formation of hydrogen sulfide (H2S) and other volatile sulfur compounds (VSCs), which can mask positive aromas at low concentrations and result in unpleasant aromas such as rotten egg, cabbage, garlic, and rubber at higher concentrations. Despite the large body of work researching formation of H2S during wine fermentation, it remains a frequent issue. Furthermore, much less is known about the formation of these VSCs during post-fermentation aging and impact of factors such as wine lees composition. In particular, little is known about the role of lees composition on the VSC precursor compounds cysteine, methionine, and glutathione. In addition, while the impact of grape must nitrogen content on H2S formation has been documented, the effect of nitrogen composition on the formation of VSCs is relatively unknown. This study investigated the role of wine lees quantity and composition on formation of VSCs as well as the impact of nitrogen concentration and composition. The role of elemental sulfur in the formation of VSCs during and after fermentation was also investigated. The impact of wine lees was investigated by fermenting Pinot noir grapes with either a common Pinot noir yeast, Saccharomyces cerevisiae RC212, or a non-H2S producing yeast S. cerevisiae P1Y2. After fermentation was complete, wines were settled for 0, 24, or 96 hours, resulting in wines with high, medium, or low amounts of lees. Wines were sampled after 0, 14, 30, 60, 90, 180, and 270 days and assessed for VSCs by GC-PFPD and for free amino acids by HPLC-DAD. Glutathione was also assessed after 0 and 30 days by LC-MS/MS. Results showed an increase in methionine and cysteine between 14 and 30 days, which corresponded to an increase in H2S at the same time. Concentrations of methionine and cysteine increased during aging and were influenced by yeast strain and level of wine lees. Wines produced using P1Y2 contained higher concentrations of methionine and cysteine than wines produced by RC212 at each level of wine lees; higher lees levels also resulted in higher amounts of cysteine and methionine. Increasing levels of methionine and cysteine did not necessarily result in increased amounts of VSCs in the wines. In general, the concentrations of VSCs in the wines were below sensory thresholds. Hydrogen sulfide decreased after the first 30 days of aging, but other VSCs such as methanethiol and dimethyl sulfide persisted at low levels. The influence of concentration and composition of yeast assimilable nitrogen (YAN) was also investigated. Fermentations were performed by either a high H2S producing Saccharomyces cerevisiae strain (UCD522) or a non-H2S producing S. cerevisiae strain (P1Y2). YAN was adjusted to high (346 mg/L) and low (112 mg/L) treatments containing mostly primary amino acids; a third treatment was prepared where the majority of the 346 mg/L YAN was derived from diammonium phosphate (DAP). Lead acetate tubes were used to monitor H2S production during fermentation; wines were lead acetate tubes then assessed for additional VSCs by GC-PFPD. YAN concentration and composition affected H2S production during fermentation. Treatments fermented by UCD522 with high DAP had increased formation of H2S late in fermentation and significantly more methyl thioacetate in the wine post-fermentation. In addition to YAN, the presence of elemental sulfur is also known to impact VSCs. Pinot noir was fermented with an addition of 0, 5, or 15 mg/g elemental sulfur. Fermentations were conducted by UCD522 or P1Y2 at 27°C and H2S production was again measured using lead acetate tubes. Wines were assessed for additional VSC by GC-PFPD. Addition of elemental sulfur resulted in H2S formation during the alcoholic fermentation even with non-H2S yeast. Elemental sulfur increased production of H2S late in fermentation and resulted in wines that contained higher concentrations of methyl thioacetate post-fermentation. Wines were analyzed for elemental sulfur by HPLC-DAD; almost no elemental sulfur remained in the wines post-fermentation.
Principles and Practices of Winemaking
Author: Roger B. BoultonPublisher: Springer Science & Business Media
ISBN: 1475762550
Category : Technology & Engineering
Languages : en
Pages : 616
Book Description
This essential text and reference offers a complete guide to winemaking. The authors, all well-known experts in their field, concentrate on the process of wine production, stressing the chemistry, biochemistry, microbiology and underlying science of enology. They present in-depth discussion of every aspect of the wine production process, from the selection of grapes and preparation of the must and the juice, through aging, bottling and storage of finished wines. Novices and experienced winemakers alike will find this clearly written and expertly crafted book an indispensable source of practical instruction and information.
Handbook of Enology, Volume 1
Author: Pascal Ribéreau-GayonPublisher: John Wiley & Sons
ISBN: 1119584620
Category : Technology & Engineering
Languages : en
Pages : 656
Book Description
As an applied science, enology is a collection of knowledge from the fundamental sciences including chemistry, biochemistry, microbiology, bioengineering, psychophysics, cognitive psychology, etc., and nourished by empirical observations. The approach used in the Handbook of Enology is thus the same. It aims to provide practitioners, winemakers, technicians and enology students with foundational knowledge and the most recent research results. This knowledge can be used to contribute to a better definition of the quality of grapes and wine, a greater understanding of chemical and microbiological parameters, with the aim of ensuring satisfactory fermentations and predicting the evolution of wines, an7thd better mastery of wine stabilization processes. As a result, the purpose of this publication is to guide readers in their thought processes with a view to preserving and optimizing the identity and taste of wine and its aging potential. This third English edition of The Handbook of Enology, is an enhanced translation from the 7h French 2017 edition, and is published in print as individual themed volumes and as a two-volume set, describing aspects of winemaking using a detailed, scientific approach. The authors, who are highly-respected enologists, examine winemaking processes, theorizing what constitutes a perfect technique and the proper combination of components necessary to produce a quality vintage. They also illustrate methodologies of common problems, revealing the mechanism behind the disorder, thus enabling a diagnosis and solution. Volume 1: The Microbiology of Wine and Vinifications addresses the first phase of winemaking to produce an "unfinished" wine: grading grape quality and maturation, yeast biology then adding it to the grape crush and monitoring its growth during vinification; and identifying and correcting undesired conditions, such as unbalanced lactic and acetic acid production, use of sulfur dioxide and alternatives, etc. Coverage includes: Wine microbiology; Yeasts; Yeast metabolism; The conditions for the development of yeasts; Lactic acid bacteria, their metabolism and their development in wine; Acetic bacteria; The use of sulfur dioxide in the treatment of musts and wines; Products and processes acting in addition to sulfur dioxide; Winemaking; The grape and its maturation; Harvesting and processing of grapes after harvest; Vinification in red and white wine making. The target audience includes advanced viticulture and enology students, professors and researchers, and practicing grape growers and vintners.
Flavor Chemistry of Wine and Other Alcoholic Beverages
Author: Michael C. QianPublisher: OUP USA
ISBN: 9780841227903
Category : Science
Languages : en
Pages : 0
Book Description
Describes the advances in flavor chemistry research related to alcoholic beverages.
Factors Affecting Hydrogen Sulfide Production During Fermentation
Author: Ioannis FlerianosUnderstanding Wine Chemistry
Author: Andrew L. WaterhousePublisher: John Wiley & Sons
ISBN: 1119894093
Category : Technology & Engineering
Languages : en
Pages : 565
Book Description
Understanding Wine Chemistry Understand the reactions behind the world’s most alluring beverages The immense variety of wines on the market is the product of multiple chemical processes – whether acting on components arising in the vineyard, during fermentation, or throughout storage. Winemaking decisions alter the chemistry of finished wines, affecting the flavor, color, stability, and other aspects of the final product. Knowledge of these chemical and biochemical processes is integral to the art and science of winemaking. Understanding Wine Chemistry has served as the definitive introduction to the chemical components of wine, their properties, and their reaction mechanisms. It equips the knowledgeable reader to interpret and predict the outcomes of physicochemical reactions involved with winemaking processes. Now updated to reflect recent research findings, most notably in relation to wine redox chemistry, along with new Special Topics chapters on emerging areas, it continues to set the standard in the subject. Readers of the second edition of Understanding Wine Chemistry will also find: Case studies throughout showing chemistry at work in creating different wine styles and avoiding common adverse chemical and sensory outcomes Detailed treatment of novel subjects like non-alcoholic wines, non-glass alternatives to wine packaging, synthetic wines, and more An authorial team with decades of combined experience in wine chemistry research and education Understanding Wine Chemistry is ideal for college and university students, winemakers at any stage in their practice, professionals in related fields such as suppliers or sommeliers, and chemists with an interest in wine.
Advances in Grape and Wine Biotechnology
Author: Antonio MorataPublisher: BoD – Books on Demand
ISBN: 1789846129
Category : Technology & Engineering
Languages : en
Pages : 298
Book Description
Advances in Grape and Wine Biotechnology is a collection of fifteen chapters that addresses different issues related to the technological and biotechnological management of vineyards and winemaking. It focuses on recent advances in the field of viticulture with interesting topics such as the development of a microvine model for research purposes, the mechanisms of cultivar adaptation and evolution in a climate change scenario, and the consequences of vine water deficit on yield components. Other topics include the metabolic profiling of different Saccharomyces and non-Saccharomyces yeast species and their contribution in modulating the sensory quality of wines produced in warm regions, the use of new natural and sustainable fining agents, and available physical methods to reduce alcohol content. This volume will be of great interest to researchers and vine or wine professionals.
Biology of Microorganisms on Grapes, in Must and in Wine
Author: Helmut KönigPublisher: Springer
ISBN: 3319600214
Category : Technology & Engineering
Languages : en
Pages : 711
Book Description
The second edition of the book begins with the description of the diversity of wine-related microorganisms, followed by an outline of their primary and energy metabolism. Subsequently, important aspects of the secondary metabolism are dealt with, since these activities have an impact on wine quality and off-flavour formation. Then chapters about stimulating and inhibitory growth factors follow. This knowledge is helpful for the growth management of different microbial species. The next chapters focus on the application of the consolidated findings of molecular biology and regulation the functioning of regulatory cellular networks, leading to a better understanding of the phenotypic behaviour of the microbes in general and especially of the starter cultures as well as of stimulatory and inhibitory cell-cell interactions during wine making. In the last part of the book, a compilation of modern methods complete the understanding of microbial processes during the conversion of must to wine.This broad range of topics about the biology of the microbes involved in the vinification process could be provided in one book only because of the input of many experts from different wine-growing countries.
Wine Chemistry and Biochemistry
Author: M. Victoria Moreno-ArribasPublisher: Springer Science & Business Media
ISBN: 0387741186
Category : Technology & Engineering
Languages : en
Pages : 729
Book Description
The aim of this book is to describe chemical and biochemical aspects of winemaking that are currently being researched. The authors have selected the very best experts for each of the areas. The first part of the book summarizes the most important aspects of winemaking technology and microbiology. The second most extensive part deals with the different groups of compounds, how these are modified during the various steps of the production process, and how they affect the wine quality, sensorial aspects, and physiological activity, etc. The third section describes undesirable alterations of wines, including those affecting quality and food safety. Finally, the treatment of data will be considered, an aspect which has not yet been tackled in any other book on enology. In this chapter, the authors not only explain the tools available for analytical data processing, but also indicate the most appropriate treatment to apply, depending on the information required, illustrating with examples throughout the chapter from enological literature.