Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Special yeast reduce alcohol, improve wine

17.01.2014
A team of Australian researchers has taken a giant step towards controlling a growing problem in the wine community. They have identified special yeast that produce a lower level of alcohol, helping to preserve the flavor. Their research is published ahead of print in the journal Applied and Environmental Microbiology.

The alcoholic content of wine has crept gradually northward in the last 10-15 years, from 12-12.5 percent to beyond 15 percent. What might sound trivial to aficionados of hard liquor is seen by some oenophiles as a disturbing trend, threatening the flavor and character of some wines. That, plus issues of public health, as well as taxes (in some countries, on alcoholic content), have created a need for approaches to lowering alcohol content.

The investigation began with a systematic screening of non-Saccharomyces yeast as a means of achieving such a reduction, says corresponding author Cristian Varela of the Australian Wine Research Institute, Adelaide, South Australia. The investigators evaluated 50 different isolates from 40 species and 24 genera for their capacity to produced wine with reduced ethanol concentration. They chose the most successful of these yeasts, Metschnikowia pulcherrima AWRI1149, for experiments in which it was set to work separately on Chardonnay and Shiraz musts.

Once the slower-growing Metschnikowia yeasts had consumed 50 percent of the sugar, S. cerevisiae were added to the mix to complete the process. This "sequential inoculation" reduced the alcohol content in Shiraz from 15 percent to 13.4 percent (and somewhat less in Chardonnay). Controls not inoculated with non-Saccharomyces strains did not produce reduced alcohol content, according to the report.

"The reduction isn't all that great, but it's in the right direction, and with more work, they might get that even lower, perhaps by letting the non-Saccharomyces yeast go longer before you throw in the Saccharomyces, says Alan Bakalinsky, of Oregon State University, Corvallis, who was not involved in the research.

This reduction in alcohol will be of great benefit to the industry says Louisa Rose, of Yalumba and Hill-Smith Family Vinyards, Angaston, South Australia, who is also a director of the Australian Wine Research Institute. "It is using techniques—sequential fermentation—that can easily be used in the winery on a commercial scale."

Previous studies investigating the effects of non-Saccharomyces yeasts on alcoholic fermentation have focused on few species and been concerned principally with the formation of the flavor compounds that might impact negatively on wine quality. None of these led to reductions in alcohol content as substantial as those he reported, says Varela.

The rise in alcohol content in wine has resulted from later harvesting of red grapes. This allows the tannins—responsible for astringency and bitterness—to soften, and in some varieties, it helps minimize the presence of off-flavors, like methoxypyrazines (green pepper/asparagus sensory notes.) But on the downside, the boost in alcohol content reduces aroma and flavor intensity, as well as otherwise impairing the oenological experience. Reducing the alcohol would enable the best of both worlds.

It would also reduce consumer costs in countries where alcohol consumption is taxed, and accede to national and international public health recommendations to lower the alcohol content of alcoholic beverages, such as wine.

A copy of the manuscript can be found online at http://bit.ly/asmtip0114f. The final version of the article is scheduled for the March 2014 issue of Applied and Environmental Microbiology.

Applied and Environmental Microbiology is a publication of the American Society for Microbiology (ASM). The ASM is the largest single life science society, composed of over 39,000 scientists and health professionals. Its mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.

Jim Sliwa | EurekAlert!
Further information:
http://www.asmusa.org

More articles from Life Sciences:

nachricht How to become a T follicular helper cell
31.07.2015 | La Jolla Institute for Allergy and Immunology

nachricht Heating and cooling with light leads to ultrafast DNA diagnostics
31.07.2015 | University of California - Berkeley

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Quantum Matter Stuck in Unrest

Using ultracold atoms trapped in light crystals, scientists from the MPQ, LMU, and the Weizmann Institute observe a novel state of matter that never thermalizes.

What happens if one mixes cold and hot water? After some initial dynamics, one is left with lukewarm water—the system has thermalized to a new thermal...

Im Focus: On the crest of the wave: Electronics on a time scale shorter than a cycle of light

Physicists from Regensburg and Marburg, Germany have succeeded in taking a slow-motion movie of speeding electrons in a solid driven by a strong light wave. In the process, they have unraveled a novel quantum phenomenon, which will be reported in the forthcoming edition of Nature.

The advent of ever faster electronics featuring clock rates up to the multiple-gigahertz range has revolutionized our day-to-day life. Researchers and...

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

California 'rain debt' equal to average full year of precipitation

31.07.2015 | Physics and Astronomy

Telescopes team up to find distant Uranus-sized planet through microlensing

31.07.2015 | Physics and Astronomy

Quantum Matter Stuck in Unrest

31.07.2015 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>