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A simple and rapid method was developed to identify the source species of pufferfish products. Randomly amplified polymorphic DNA RAPD analysis was applied to identify 8 species of pufferfish. Commercial kits were used for DNA extraction and amplification. Simultaneous identification was possible by polyacrylamide gel electrophoresis of PCR products. Two primers were chosen based on the result of pre-examination with 40 primers, and the PCR conditions were optimized. Characteristic RAPD patterns were obtained for each pufferfish species. The developed method was applied to identify the source species of 26 pufferfish products. The results suggest that the developed method would be useful for verification of the labeled species of pufferfish products.

A rapid, simple and inexpensive method was developed for identifying the species of animal hair present as a contaminant in food. A polymerase chain reaction-amplified product length polymorphism (PCR-APLP) assay was applied to identify hair from human and others (cat, dog, rabbit, rat and mouse) or livestock (pig, cattle, horse, sheep, goat and chicken). The PCR primers were designed to amplify partial sequences from the 16S rRNA gene to the NADH dehydrogenase subunit 1 (ND1) gene of mitochondrial DNA (mtDNA), which generate different length fragments for different animal species. The PCR-APLP assay utilized two PCR reaction tubes, each of which contained one universal forward primer and six species-specific reverse primers (human, etc. or livestock). Simultaneous identification was possible by agarose gel electrophoresis of PCR products. The developed method was applied to identify the source species of 52 animal hair samples. The expected amplified product length was obtained from all samples.

Shiitake mushrooms (Lentinula edodes) cultivated on bed-log are known to accumulate radiocaesium. Since the Fukushima-Diichi nuclear power plant accident (2011), the violation rate has been higher for log-cultivated shiitake than that for agricultural products or other foodstuffs. When testing shiitake mushrooms for radionuclide contamination, the validation of the sampling plan can be severely compromised by the heterogeneous contamination within shiitake lots. Currently, few data are available on the statistical properties of the radiocaesium contamination of log-cultivated shiitake. In this paper, shiitake lots contaminated by radiocaesium were identified and the distribution of the radiocaesium concentration within the lots investigated. The risk of misclassifying shiitake lots was predicted from the operating characteristic curve generated from Monte Carlo simulations and the performance of various sampling plans was evaluated. This study provides useful information for deciding on an acceptable level of misclassification risk.