Rapid on-site measurement of the freshness of rice on a micro electrochemical device

Freshness is an important factor that determines the quality of rice. However, to measure the freshness, the procedures for conventional methods are complicated or the instrument used for the measurement is expensive. If there is a portable device to measure the freshness of rice easily at home, it will be of great help for consumers. In this study, we have developed an electrochemical microdevice that can measure the freshness of rice based on the measurement of the activity of an enzyme, peroxidase. In the existence of the substrates for the enzyme including hydrogen peroxide, a marked difference in generated current was observed between new rice and old rice, which agreed well with results obtained by the conventional fluorometric and guaiacol methods. The results demonstrate that the on-site rapid measurement of freshness can actually be carried out using our device.