Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The unique taste of ‘smoky’ tomatoes is caused by one missing enzyme

08.10.2013
The absence or presence of one specific enzyme causes tomatoes to be described as ‘smoky’ or not by taste experts.

This is the result of research by Wageningen UR, which studied the taste of 94 tomato varieties using expert taste panels. The tomatoes were also evaluated for their metabolite content, such as aroma volatiles, and for their DNA composition.

When a tomato plant is able to produce the identified enzyme, it converts precursors of the ‘smoky’ volatiles into others which are odourless and tasteless. As smoky tomatoes cannot produce this enzyme, the precursors of smoky volatiles are not converted. In these tomatoes, smoky volatiles can be released upon biting and chewing, giving rise to a smoky aroma.

This new knowledge can help tomato breeding companies to select more specifically for flavour characteristics. The research was performed within the framework of the Dutch Genomics Initiative, Centre for Biosystems Genomics (CBSG).

Tomatoes come in many varieties and sizes. Most supermarkets sell around ten different sorts, many of which are especially popular for their flavour. Because preferences differ, some people choose one variety, while others choose another.

Wageningen UR supports Dutch tomato-breeding companies in developing tomatoes with a good, either new or existing, flavour. Some of the Wageningen scientists study the flavour of tomatoes that are already ‘in the pipeline’ at the breeding companies. This allows these companies to market new varieties with confidence. Other Wageningen scientists look at how and why the flavours of the tomatoes vary.

When taste panels describe the flavour of tomatoes, they use words like ‘sweet’, ‘sour’, ‘mealy’ and ‘tomato aroma’. Whether something tastes good or bad is a matter of preference. But taste experts are in fact able to indicate to what extent tomatoes are ‘sweet’ or ‘sour’. One of the flavour characteristics the experts use is ‘smoky’; a taste that is similar to the typical flavour of smoked cheese, meat or fish. Roughly half of the tomatoes studied were classified as ‘smoky’ by the taste experts. The scientists at Wageningen UR discovered the mechanisms underlying this ‘smoky’ flavour.

The scientists compared the results of the taste experts to their analysis of the components in the tomatoes and discovered that all ‘smoky’ tomatoes contain three types of aromatic volatiles. These volatiles are stored in the fruit after coupling to a double sugar molecule, as disaccharides. While the three resulting components are tasteless by themselves, when a tomato is cut or eaten the stored volatile-disaccharides are quickly cleaved and the aromatic volatiles are released into the air. These ‘breakdown products’ give the tomatoes a ‘smoky’ flavour.

In some tomatoes the three disaccharides are enzymatically coupled to a third sugar molecule and stored as trisaccharides. These trisaccharides cannot be broken down to smoky aroma volatiles when tomatoes are cut or eaten. Therefore these tomatoes do not have a smoky flavour. Thanks to a combination of DNA analyses, gene expression analyses and metabolite analyses, the Wageningen scientists found the gene coding for the enzyme that converts ‘smoky’ disaccharides into ‘non-smoky’ trisaccharides.. In smoky tomatoes the identified gene is ‘cripple’ and no longer codes for a functional enzyme. As a result, the smoky precursors cannot be converted into the non-tasting trisacharides.

The Wageningen scientists hope that the new knowledge on the background of the smoky flavour of tomatoes will help breeding companies take a more targeted approach towards specific flavours.

The results have been published in the scientific magazine Plant cell.

Note for the editor
More information: Erik Toussaint, press official, T: +31 651 56 59 49
Images, free of copyrights:
- https://picasaweb.google.com/115915961286327465946/Tomatenproeven#
- Sensory trial of a tomato by a member of a tasting panel
- Graph presenting aromatic volatiles of smoky en non-smoky tomatoes
- Graph showing the research path: from 23.000 genes to the gene coding for the enzyme

Publication: http://www.plantcell.org/content/25/8/3067.abstract.html?etoc

Erik Toussaint | Wageningen University
Further information:
http://www.wageningenur.nl/

Further reports about: DNA Dutch landscape Genomics Wageningen sugar molecule

More articles from Life Sciences:

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
22.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>