Abstract
To develop a system that measures the freshness of rice quickly and conveniently without changing rice quality, we selected a technology that utilizes a fluorescence imaging method with UV-light excitation. The system consists of two UV-A fluorescent lamps and a blue LED with a low-pass filter, a cooled CCD camera with an IR cutoff filter to capture the fluorescence image on a PC, and image processing software for measuring the fluorescence intensity of the image. Using this system on long-stored samples of rough rice and brown rice, the experiments confirmed that there was a high correlation between the results (fluorescence intensity) and the conventional indices such as free fat acidity and guaiacol reaction. Deterioration and/or aging of stored rice advanced as the storage temperature rose or the storage period lengthened, and simultaneously the tendency for fluorescence intensity increased, indicating that this system can be used for monitoring aging of rice.
