Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The turbidity of wine has an influence on the aroma of the ferment, but not on the accumulation of biogenic

27.11.2006
The turbidity of red wine during its ageing in oak casks has an influence on the accumulation of volatile compounds and, thereby, on the wine’s aroma, but not on the accumulation of biogenic amines.

This is the conclusion of Nerea Jiménez Moreno in her PhD thesis defended at the Public University of Navarre. The PhD is entitled, “Ageing of red wine with different turbidity in barrels of oak. - the volatile composition and content of amines”.

After studying the ageing process of the same wine, filtered and unfiltered, over an eighteen-month period, Nerea Jiménez concluded that, in the unfiltered wine, the “lees” - the remains of yeasts, bacteria and other particles in suspension and that precipitate during the wine’s time in the cask – are able to retain certain volatile compounds that are responsible for the wine’s aroma. As regards the biogenic amines, the author explains that, during the ageing process of the wine, amines still continue to form but that the turbidity of the wine does not influence the accumulation of these compounds.

The aroma of the wine

Aroma is a highly important aspect determining the quality of wine. Primary aromas are those belonging to and characteristic of the variety of grape used for the elaboration of the wine. The compounds originating from fermentation – the most abundant – are responsible for the fruity and/or flowery aromas of wine and are known as secondary aromas. Finally, the compounds giving rise to the tertiary aromas come from the oak wood during the ageing process in the cask and subsequent evolution in the bottle.

With the ageing (crianza) of the wine in oak casks, not only is a greater aromatic and flavour complexity sought but, during this process, a series of simultaneous physical-chemical phenomena are produced that give the wine greater clarity and stability.

However, the ageing of wine in oak casks is an expensive process, largely due to the cost of acquiring the barrels as well as the time that the product has to remain stored in the wine cellar. Because of this, it is very important to know the factors influencing the maturing process of the wine and how to influence these in order to optimise the process.

In this sense, Ms Jiménez’s study has enabled the conclusion to be drawn that the turbidity of wine during the ageing process had influence both on the evolution of fermentation esters and on the accumulation of volatile compounds originating in the oak barrel; but that the fixation of the aromatic compounds of the lees depends on the composition of the latter and on the grape used.

As regards the sensorial implications of these findings, a wine-tasting session was carried out, with both filtered and unfiltered wines, after maturing between three and twelve months. The conclusion was that the filtered wines were more pleasant on the nose but more aggressive on the palate, while the unfiltered wines stood out for their qualities on the palate. In fact, the tasters were able to distinguish between filtered and unfiltered wines. The scientific literature coincides, effectively, in that the lees provide greater roundness and untuosity to the wine, which enhances the sensations on the palate of the consumer on drinking this product.

Biogenic amines

Another aspect related to the quality of wines that has sparked great interest over the past few years and that Ms Jiménez has studied for her research, is the presence of biogenic amines in this alcoholic drink. These nitrogenated compounds are mainly formed during the alcoholic and malolactic fermentations of the wine, their importance lying in the negative effects on human health that can arise with their ingestion. Consuming wine with high concentrations of these amines, principally histamine and tyramine, can cause headaches, allergic reactions, heart palpitations, high blood pressure, diarrhoeas, and so on.

Moreover, the presence of high concentrations of histamine in wines can give rise to export restrictions, as a number of countries are planning to place recommended limits on this histamine content in wines; in other countries, such as Switzerland, they have already imposed this limit. To this end, it is important to know the evolution of the biogenic amines during the cask maturing of the wine as their final concentration can determine its exportability.

In her PhD, Nerea Jiménez concluded that there exists a grand variety in the evolution of biogenic amines during the maturing process of the wine in the barrel. For example, histamine and tyramine, the most toxic, are formed at the beginning of the process and subsequently their concentration falls, possibly due to their degradation. Nevertheless, putrescine and cadaverine, both of which boost the toxic action of the former two amines, build up in the wine throughout the whole ageing process.

These findings are important in that they warn the enologist not to drop their guard in the control of these post-malolactic fermentation compounds, especially if part of the wine production is to be exported.

Irati Kortabitarte | alfa
Further information:
http://www.elhuyar.com
http://www.basqueresearch.com/berria_irakurri.asp?Gelaxka=1_1&Berri_Kod=1095&hizk=I

Further reports about: Accumulation CASK Fermentation amines biogenic compounds concentration maturing turbidity volatile

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>