Discriminant Analysis of Undaria pinnatifida Production Areas Using Trace Elemental Analysis

Increasingly, attention is being paid to declaring the origin of agricultural and marine products after the advent of the bovine spongiform encephalopathy (BSE; commonly known as mad-cow disease). The display of the production centers on U. pinnatifida has been required in Japan since 2006. As an example of testing in another marine product, near-infrared spectra (NIR) and trace elemental analysis of U. pinnatifida are proven effective methods for discriminating production centers by us and Food and Agricultural Materials Inspection Center (FAMIC). In the present study, we found that X-ray fluorescence analysis of Br was also effective for the discrimination of production centers. The results of our study suggest that a combination of NIR and X-ray fluorescence analysis is a convenient and efficient method for determination due simple sampling procedures and increased effectiveness. 1. Introduction Issues related to the safety of foods have gathered the attention of consumers following the advent of bovine spongiform encephalopathy (BSE). There have also been improper displays of production centers on some marine products such as clams (Undaria pinnatifida). Hence, there is an urgent need for establishment of convenient and efficient scientific methods for discriminating the production centers. In our earlier studies [1, 2], we reported that near-infrared spectroscopy is a useful method for discriminating production areas [3]. In addition, Food and Agricultural Materials Inspection Center (FAMIC) reported that the inorganic elemental analysis results were valid markers for discriminating the production areas between China, Korea, and Japan (Sanriku and Naruto) of U. pinnatifida by ICP-MS spectroscopy [4–7]. Analysis results of these studies showed that the error rates were 0%, 26%, and 6% for samples from China, Korea, and Japan, respectively. In our present study, we hypothesize that additional accuracy can be achieved by classification and regression trees (CART [8, 9]) as a discriminant method. In addition we explored the possibility of a more convenient discrimination method using elemental analysis of Br. The main purpose of this paper is reporting the possibility of the screening test, which would be conveniently applicable without using expensive and large equipments like an ICP-MS and so on, for discriminating production areas. Some NIR or X-ray fluorescence equipments are portable and the usages are not so complicated. 2. Materials and Methods Results from the study in [5] involving ICP-MS analysis for 22 elements, namely, Al, Ba, Ca, Fe, K,