Mulling over the aromas of wine

July 12, 2017, American Chemical Society
Credit: CC0 Public Domain

A fine wine has an ideal balance of ingredients. Too much or too little of a component could mean the difference between a wine with a sweet and fruity aroma and one that smells like wet newspaper. To help wineries avoid off-aromas, a team reports in ACS Sensors a sensitive device for detecting a compound that can affect the beverage's fragrance.

Acetaldehyde is frequently found in a lot of places and foods, such as fruits, vegetables and human saliva. When present in high amounts in , it produces an unpleasant odor and affects the . Therefore, it is important for winemakers to monitor the acetaldehyde levels, which can vary with temperature, pH and oxygen concentrations. Current methods involve trained experts, long processing times and complex equipment. Kohji Mitsubayashi and colleagues propose a sensitive, versatile detector that is more selective than its predecessors.

The team tested for acetaldehyde in nine different wines, both red and white. The new detector produced results comparable to those obtained with traditional methods, but was simpler to operate and produced real-time results. The researchers say that the device could provide wineries with a more practical for monitoring this make-or-break ingredient.

Credit: American Chemical Society

Explore further: Corralling stink bugs could lead to better wine

More information: Kenta Iitani et al. Improved Sensitivity of Acetaldehyde Biosensor by Detecting ADH Reverse Reaction-Mediated NADH Fluoro-Quenching for Wine Evaluation, ACS Sensors (2017). DOI: 10.1021/acssensors.7b00184

Acetaldehyde (AcH) is found in ambient air, foods, and the living body. This toxic substance is also contained in wine and known as an important ingredient affecting the quality of wine. Herein, we constructed and evaluated two different fiber-optic biosensors for measurement of AcH in the liquid phase (AcH biosensor) using aldehyde dehydrogenase (ALDH) or alcohol dehydrogenase (ADH). The AcH biosensor measured a concentration of AcH using fluorescence intensity of a reduced form of nicotinamide adenine dinucleotide (NADH) that was produced or consumed via catalytic reaction of the respective enzyme. In the AcH measurement system, an ultraviolet light emitting diode (UV-LED) and photomultiplier tube (PMT) were connected to a bifurcated optical fiber and were used to excite and detect NADH. A sensing region was developed using an optical fiber probe and an enzyme-immobilized membrane, buffer pH, and concentrations of a coenzyme in buffer solution for ALDH forward reaction and ADH reverse reaction were optimized, and the dynamic ranges were compared. ADH-mediated AcH biosensor showed higher sensitivity, wider dynamic range (1–500 μM), and capability of rapid measurement (less than 3 min) than ALDH-mediated AcH biosensor (5–200 μM). ADH biosensor also presented a high selectivity and allowed measurement of AcH in 9 different wine samples (5 red and 4 white wines). The determined concentrations were comparable to those measured by NADH absorbance method, which validated the accuracy of the ADH biosensor in AcH measurement.

Related Stories

Corralling stink bugs could lead to better wine

January 25, 2017

To wine makers, stink bugs are more than a nuisance. These tiny pests can hitch rides on grapes going through the wine making process, releasing stress compounds that can foul the smell and taste of the finished product. ...

'Cold soak' process turns up the heat on wines

May 27, 2015

Those pondering which elements make the best drop of wine may be surprised to learn different climates produce mixed results when it comes to wines made using the 'cold soak' process.

Advice for bag-in-box wine drinkers: Keep it cool

December 5, 2012

Bag-in-box wines are more likely than their bottled counterparts to develop unpleasant flavors, aromas and colors when stored at warm temperatures, a new study has found. Published in ACS' Journal of Agricultural and Food ...

Recommended for you

Universal pH regulated assembly of DNA nanostructures

May 23, 2018

DNA, the carrier of genetic information, has become established as a highly useful building material in nanotechnology. One requirement in many applications is the controlled, switchable assembly of nanostructures. In the ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.