Coffee producers could use the electronic tongue for quality control.
Hand-held tasting device displays highly discriminating palate.
A new hand-held electronic tongue promises to give accurate and reliable taste measurements for companies currently relying on human tasters for their quality control of wine, tea, coffee, mineral water and other foods.
Human tasters are still irreplaceable for subtile products such as fine wines and whiskies. But their sense of taste saturates after a while, losing its discriminating edge. The device made by Antonio Riul of EMBRAPA Instrumentação Agropecuária in São Carlos, Brazil, and colleagues rivals human taste buds and never tires1.
Humans have long been thought to detect four basic taste types: sweet, salty, sour and bitter. Very recently, a fifth candidate basic taste was identified: umami, the taste of monosodium glutamate, characteristic of protein-rich foods. Taste buds are believed to contain receptor molecules that trigger nerve signals when they encounter flavour-imparting molecules.
The details of this system are still not understood. Each taste sensation may correspond to a fingerprint signal induced by the differential activation of the various taste receptors. The electronic tongue works on this principle.
It contains four different chemical sensors. The sensors comprise very thin films of three polymers and a small molecule containing ruthenium ions. These materials are deposited onto gold electrodes hooked up to an electrical circuit.
In a solution of flavoursome substances such as sugar, salt quinine (bitter) and hydrochloric acid (sour), the thin sensing films absorb the dissolved substances. This alters the electrical behaviour (the capacitance) of the electrodes in a measurable way.
Each sensor responds differently to different tastes. A composite sensor that incorporates all four therefore produces an electronic fingerprint of the taste. The researchers combine these responses into a single data point on a graph. The position on the graph reflects the type of taste: sweet lies towards the top left, for example, sour towards the top right.
Different beverages have a characteristic location on the graph. Coffee is low down around the middle, for instance. Some tastes that might be expected to differ only slightly, such as distilled and mineral water, lie far apart on the graph and so can be clearly distinguished.
The electronic fingerprint allows the team to predict what a particular solution will taste like, says Martin Taylor of the University of Wales at Bangor, who collaborated with the Brazilian team. "It might fit in the salty or sweet domain, for example," he says. Taylor anticipates that the device will probably be able to discriminate the umami taste too, giving it a refined palate for sushi.
PHILIP BALL | © Nature News Service
Cooling buildings with solar heat
26.09.2016 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH
Philippines’ microsatellite captures best-in-class high-resolution images
22.09.2016 | Hokkaido University
The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...
With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...
For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.
Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...
At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.
In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...
Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.
K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...
23.09.2016 | Event News
20.09.2016 | Event News
16.09.2016 | Event News
26.09.2016 | Materials Sciences
26.09.2016 | Materials Sciences
26.09.2016 | Materials Sciences