We analyzed the fluorescence luminescence spectrum of rice to develop a method for measuring the freshness of rice quickly and conveniently without affecting the quality of rice. Our observation revealed that the spectra of brown rice and its lipids before and after deterioration were similar. In addition, the fluorescent intensities of the spectra were higher in deteriorated samples. Therefore, we believed that fluorescence luminescence was associated with the lipid content of brown rice, and that lipid peroxide generated by initial oxidation of neutral lipids was responsible for fluorescence luminescence. Thus, increase in the fluorescent intensity of rice was useful as a freshness deterioration index in brown rice. We believed that this method, which evaluates the oxidation of brown rice(freshness deterioration)using ultraviolet light excitation, is effective for assessing the quality of brown rice with regard to freshness.
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