Scientists develop sensor to detect honey adulteration

In a sweet world of honey, adulteration is a bitter truth. Honey is often purchased for its purity and health benefits, but it sometimes contains hidden additives, most commonly water.

Standard methods to detect honey adulteration can be expensive and can have complicated operation methods or low accuracy.

In Review of Scientific Instruments, from AIP Publishing, a team of scientists from the Nanjing University of Aeronautics and Astronautics and the Hebei University of Technology developed a microwave microstrip line planar resonator sensor tool to detect water adulteration in honey. The compact tool is designed to be cost-effective and easily fabricated.

The sensor is fabricated on a dielectric substrate, which is an insulator that can support electrostatic fields, such as ceramic or glass. There are three thin copper strips on top, separated by two gaps. The length of the middle strip and the electric field intensity at the gaps determine the resonance frequency of the device.

According to author Zhen Li, water changes how the electromagnetic field around honey behaves. “When placed in the sensor, adulterated honey shifts the sensor’s resonance frequency. By measuring this shift, we can detect water adulteration in honey,” Li said.

The team tested honey samples with varying water content. They found that the sensor’s resonance frequency consistently decreased with increased added water content.

The device could inspire further applications in liquid analysis, in industries such as food quality control, pharmaceuticals and petrochemicals, for detecting impurities or composition changes, potentially advancing sensing technology.

“We aim to extend our research to detect adulteration in other liquid products and develop more sensitive sensors for broader applications in quality control and food safety, starting with the impact of temperature on our sensor's performance,” Li said.

Image credit: iStock.com/AndreyCherkasov