| heal.abstract |
The potential for detection of non-metallic foreign materials in food using X-ray spectral analysis method was discussed. X-ray measuring system with CdTe crystal sensor was developed and X-ray spectrum of food could be measured and analyzed. X-ray linear absorption coefficients (μ) at each X-ray photon energy level of various materials were calculated from X-ray spectra. As the μ value was shown a function of X-ray characteristic of material, it was considered to be valid for detection of foreign material in food. The vinyl chloride plate in distilled water was investigated as a simple model. The percentage and different type of foreign materials in uniform sample could be estimated by measurement of peek position of derivative X-ray spectrum. The X-ray spectrum measuring system was then tried to be applied for detection of foreign materials in food. Three samples of hamburger patty, one free of foreign materials and two with foreign materials (glass and vinyl chloride) were tested. Peek position of derivative X-ray spectrum at hamburger patty without foreign materials was 15.5 keV and that at hamburger patty with glass and vinyl chloride plate moved to 17.5 and 17.0 keV, respectively. These results showed that, the X-ray spectrum analysis method has potential and can be applied in detecting non-metallic foreign materials in food with a proper threshold value at derivative X-ray spectrum. However, in practical use, the effect of thickness, mixing material and unevenness of material have to considered in the X-ray measurement. It is expected that different types of non-metallic foreign materials in various kinds of foods could be automatically detected by the X-ray spectrum measuring system with CdTe crystal sensor. |
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