Some people like spicy food – the spicier the better. Others go out of their way to avoid scalding capsaicin, the very compound that gives chili peppers their spice. Researchers have developed a bizarrely shaped portable device that resembles a chili pepper. What for? This will help determine how much capsaicin is in the pepper. Scientists report their findings in the journal ACS Applied Nano Materials.
Chili peppers are a popular food ingredient throughout the world. Thanks to capsaicin, chili not only has a pungent spicy taste. It is also beneficial for health due to its antioxidant, anti-carcinogenic, and anti-inflammatory properties. Therefore, there is an increasing demand for capsaicin as a dietary supplement and pharmaceutical agent. Warakorn Limbut of the Department of Life Sciences at Prince of Songkla University in Thailand and his colleagues wanted to develop a simple, accurate, and low-cost method for quantifying capsaicin in chili peppers and food samples. Other methods developed for this purpose are complex, labor-intensive, or require expensive and cumbersome instruments.
A team of scientists has created a portable device in the shape of small chili pepper. It can be connected to a smartphone to display the analysis results. The paper-based electrochemical sensor in the device consists of graphene nanoplates doped with nitrogen atoms to improve their electrical conductivity.
The researchers decided to test the device. They added a drop of diluted capsaicin to the sensor, the compound underwent oxidation and reduction reactions, resulting in an electrical current that was detected by the device. After optimizing the sensor, the scientists used it to determine the concentration of capsaicin in six dried chili peppers. They added chili to a solution containing ethanol, shaken it, and then injected a drop of the sample. The device accurately measured the capsaicin concentration from 7.5 to 90 μM in six samples.