Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli) can colonize the gastrointestinal tracts of broilers, and poultry meat is contaminated with these organisms during slaughter in poultry processing plants. We investigated the relationship between Campylobacter counts in cecal contents of broilers and those in chicken meat at eight chicken processing plants. Ceca and their breast products derived from broilers from 51 flocks were collected. Campylobacter were isolated from cecal contents of 40 (78.4%) flocks. The average number of Campylobacter in the ceca of the Campylobacter-positive flocks was 7.6 1og₁₀ CFU/g. Of 51 chicken breast products, 35 (68.6%) were contaminated with Campylobacter and the average number of Campylobacter was 1.7 1og₁₀ CFU/g. All the Campylobacter-positive products were derived from Campylobacter-positive flocks. The results of this study indicate that there is a weak positive correlation (R=0.37) between the number of Campylobacter in the ceca of broiler flocks and the number of Campylobacter in chicken meat. Of the 14 products with C. jejuni/C. coli counts of 2.0 log₁₀ CFU/g or more, nine (64.2%) were from groups with high Campylobacter (≥ 8.4 log₁₀ CFU/g) in the ceca. The Campylobacter prevalence of products from chicken flocks with C. jejuni/C. coli counts of 6.2 log₁₀ CFU/g or less in the cecal contents have a C. jejuni/C coli contamination rate of 50% (3/6) with a maximum Campylobacter count of 1.4 log₁₀ CFU/g.

The prevalence of Anisakis contamination in “ready-to-cook (RTC)” mackerel products distributed in Mie Prefecture, central area of Japan, was examined to assess the risk of anisakiasis. Of 136 mackerel fillets examined, 30 samples (22.1%) were positive for Anisakis larvae. The mackerels caught in the Sea of Japan were higher in frequency of Anisakis contamination (41.4%) compared with those from the Pacific Ocean (7.7%) (p<0.01). Number of Anisakis larvae isolated from RTC mackerel fillets was 169, of which 147 (87.0%) were still alive. Around a half of the Anisakis larvae in mackerel fillets were localized in the mid-part of the abdominal side. Two mackerel species were commonly distributed in Japan, however, Anisakis contamination was mainly observed in Scomber japonicus, but rare in S. australasicus. These findings suggest that the risk of anisakiasis transmitted through RTC mackerels might not be low, however, the risk seems to vary depending on the mackerel species, seasons, fishing grounds, and also distribution of fish products.

LC-MS/MS was used to develop a qualitative analytical method for milk, egg, buckwheat, and peanut allergens. The measurement conditions and extraction and trypsin digestion process for protein pretreatment were optimized. A sample spiked with each allergen was analyzed to evaluate the performance of the analytical method, including the extraction process. Repeatability and intralaboratory precision met the target values for all allergens, confirming the stability of the analytical method. Furthermore, the S/N ratio, retention time, and peptide ratio demonstrated the usefulness of the method as a qualitative test. Moreover, for milk and egg allergens, the equivalence of the quantitative values calculated using the developed method to those of ELISA was confirmed; however, this equivalence could not be confirmed for commercially available processed foods and some quality control samples. For buckwheat and peanut allergens, the equivalence of the quantitative values to those of ELISA could not be confirmed in the spiked sample. These findings demonstrate that this analytical method is useful as a rapid and simple qualitative test. It is also an excellent alternative to ELISA as it produces less waste and reduces environmental burden.

This study clarified the relation between thelephoric acid, the coloring molecule of a simple method of identifying Omphalotus japonicus using a beam reagent (5 w/v% potassium hydroxide ethanolic solution), and the color tone of the pileus epidermis and stained area of the stem base. Correlation was found between the shade of the pileus epidermis and stained area of the stem base and the thelephoric acid concentration. Identification methods of two types were used: direct method and extraction method. Results suggest that selecting an appropriate identification method according to the fruiting body condition will improve identification accuracy and conservation of labor.

Furthermore, no correlation was found between illudin S, a toxic component of O. japonicus, and thelephoric acid concentration. Therefore, analyzing illudin S as usual is considered necessary when identifying the cause of food poisoning associated with O. japonicus.

Food allergen analysis using LC-MS/MS has attracted attention in recent years because it can analyze multiple allergens at the same time and has high detection sensitivity and specificity. We have been actively researching for developing this testing method using LC-MS/MS. In this study, we developed the simultaneous detection method for allergens using LC-MS/MS and conducted an interlaboratory validation study in three laboratories to evaluate the effectiveness of the developed method. The study was conducted using two types of model processed foods: rice porridge and pancake. A total of nine allergens were targeted (wheat, egg, milk, peanut, buckwheat, crustaceans (shrimp and crab), walnut, and soybean). The results of the interlaboratory validation study showed that the qualitative and quantitative tests demonstrated good accuracy and, with the exception of a few allergens, exhibited a high level of agreement when compared with other laboratories. This indicates that the developed method is practical as a screening method for simultaneous detection of food allergens and can be applied to foods containing allergens.