Food Hygiene and Safety Science最新文献

This study developed a method that simultaneously detected 283 pesticide residues in brown rice using GC-MS/MS and LC-MS/MS. In this method, we examined the desirable amount of sodium chloride required for salting out and the SPE cartridge required for clean-up. Pesticide residues from the sample were extracted with acetonitrile using a homogenizer and mixed with salts including anhydrous magnesium, two types of citrate, and sodium chloride. The sample solution of the acetonitrile layer was cleaned up using the GCB/NH₂ (200 mg/200 mg, 6 mL) SPE cartridge. The determination method was validated using two concentrations (0.01 and 0.1 μg/g) of 283 pesticides based on the validation guideline of the Ministry of Health, Labor and Welfare in Japan. Of the 283 pesticides, 250 were detected satisfactorily. In addition, 59 brown rice samples sold in Tokyo were surveyed using the same method. Out of 44 samples, 12 pesticide residues below MRLs were detected. Therefore, this developed method is useful for the simultaneous determination of pesticide residues in brown rice.

Meat derived from spent hens as well as broilers is destined for human consumption. There are many reports on the prevalence and antimicrobial resistance of Campylobacter and Salmonella in broiler meat, but few in spent hen meat. Therefore, we investigated the prevalence and antimicrobial resistance of these genera in spent hen meat collected at chicken processing plants. Campylobacter and Salmonella were isolated from 47 (92.2%) and 18 (35.5%), respectively, of breast meat derived from 51 spent hen flocks. Campylobacter jejuni accounted for 87.5% of Campylobacter isolates. The highest resistant rate in C. jejuni isolates was found for ampicillin (45.3%), followed by tetracycline (14.3%) and ciprofloxacin (14.3%). There was no Campylobacter isolate resistant to erythromycin, which is recommended as a first-choice antimicrobial for humans when Campylobacter enteritis is strongly suspected. Of Salmonella isolates, the first and second most frequent serovars were Salmonella Corvallis (30.4%) and S. Braenderup (21.7%), respectively. Of Salmonella isolates, 30.4% were resistant to streptomycin. There was no Salmonella isolate resistant to ciprofloxacin, which is one of the recommended antimicrobials for humans against Salmonella enteritis. This study shows that one third of spent hen meat is contaminated with Campylobacter or Salmonella, and administration of erythromycin or cefotaxime is an effective option for patients with Campylobacter- or Salmonella- enteritis, respectively, caused by consumption of spent hen meat.

An inter-laboratory study involving 24 laboratories was conducted to validate the modified analytical method for the migration solution of heptane for the determination of bisphenol A migrating from polycarbonate food processing materials. In this study, two concentrations of samples were blindly coded. Each laboratory determined the analyte (bisphenol A, phenol and p-tert-butylphenol) concentration in each sample according to the established protocol. The obtained values were analyzed statistically using internationally accepted guidelines. Horwitz ratios were calculated based on the reproducibility relative standard deviation (RSD_R), which was estimated from the inter-laboratory study, and predicted RSD_R, which was calculated using the Horwitz/Thompson equation. Horwitz ratios of the two samples ranged from 0.15 to 0.37 for the three compounds, meeting the performance criteria of less than 2 set by the Codex Alimentarius for analytical method approval. These results showed that this modified analytical method shows good performance as an analytical method for the migration solution of heptane.

Irradiation is widely used worldwide to sterilize and kill insects in food, and prevent the germination of agricultural products. However, in Japan, food irradiation is prohibited except to prevent potato sprouting. Herein, 5,6-dihydrothymidine (DHdThd) residue-a damaged nucleoside generated from the thymidine (dThd) residue in DNA contained in food upon irradiation-was used as a detection indicator. Eight dried plant-based food samples were gamma ray-irradiated in the range from 3.2 to 8.3 kGy. Subsequently, DNA was extracted from the irradiated sample and digested into nucleosides by the three enzymes, and the test solution was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Evidently, in all samples, the concentration ratio of DHdThd to dThd in the test solution (DHdThd/dThd) was dependent on the irradiation dose; moreover, during storage under frozen conditions for at least 890 d post-irradiation, this concentration ratio was equal to that immediately after irradiation. The irradiation histories of the eight types of dried plant-based food samples were correctly detected.

An official analytical method for chlorophyll degradation compounds, including pheophorbide, in chlorella products, is described in notification Kanshoku No. 99 (May 8, 1981). However, this method has several operational issues, such as the formation of emulsion during liquid-liquid partitioning. Additionally, impurities present in the reagents (sodium sulfate decahydrate or anhydrous sodium sulfate) used to prepare saturated sodium sulfate solution can degrade pheophorbide and other related compounds, resulting in a significant decrease in analytical values. In this study, we thoroughly examined each step of the official method to enhance the operability and develop an alternative method that eliminates the need for saturated sodium sulfate solution. The developed method was evaluated for pheophorbide a and pyropheophorbide a at 100 mg%. Satisfactory analytical performance was achieved with trueness of 100% for pheophorbide a and 90% for pyropheophorbide a, and relative standard deviations of intra- and inter-day precision below 5% for both compounds. The proposed method is considered suitable for regulatory analysis of chlorophyll degradation compounds and would be useful for quality control of chlorella products.

Chicken liver is a potential source of campylobacteriosis in humans. Therefore, we determined the number of Campylobacter in chicken liver. In total, 33 vacuum-packed liver products were obtained from retail stores, and found that 27 of the 33 products (81.8%) were contaminated with Campylobacter. Moreover, Campylobacter was isolated from 138 of 149 livers (92.6%) collected from the 27 Campylobacter-positive products. The mean Campylobacter count was 2.3 log₁₀ CFU/g, while Campylobacter count in 22 of the 138 contaminated livers (15.9%) was >3.0 log₁₀ CFU/g. Furthermore, gastrointestinal tract, liver, and bile samples were collected from 35 broilers at chicken processing plants. We isolated Campylobacter from the gastrointestinal tract of 27 broilers (77.1%). Of these 27 broilers, liver of 24 broilers (88.9%) was Campylobacter-positive, with a mean Campylobacter count of 2.8 log₁₀ CFU/g. Of these 24 broilers, bile of 13 broilers (54.2%) was contaminated with Campylobacter (mean Campylobacter count, 3.5 log₁₀ CFU/mL). Among them, bile of 2 broilers had a Campylobacter count of >8.3 log₁₀ CFU/mL. Collectively, these results indicate that livers derived from broilers colonized with Campylobacter are contaminated with Campylobacter at the time of evisceration. Therefore, to prevent foodborne campylobacteriosis in humans, chicken livers should be thoroughly heated before consumption.

Severe tetrodotoxin (TTX) poisoning due to small gastropods has been documented in Japan. In this study, we investigated the TTX content of the muscles and viscera of Nassarius sufflatus collected off the coast of Futaoi Island, Shimonoseki, Yamaguchi Prefecture, Japan, to prevent the occurrence of TTX poisoning caused by this small gastropod. Live specimens were obtained, and their muscles and viscera were collected. Test solutions were prepared from tissues of specimens and analyzed for TTX by HPLC-fluorescence detection. TTX was detected in both tissues at concentrations ranging from <0.1 to 18.2 μg/g for muscle and <0.1 to 130.7 μg/g for viscera. These results suggested that N. sufflatus accumulates TTX not only in its viscera but also in its muscles, and that precautions should be taken to prevent food poisoning due to this gastropod.

A method for the rapid analysis of multiclass residual veterinary drugs in poultry muscle, egg, and raw milk was validated in accordance with Japanese guidelines. Using LC-MS/MS, 20 veterinary drugs, including sulfonamides, coccidiostats, and macrolides were analyzed in one injection. Analytes were extracted from the samples with acetonitrile and then dehydrated and salted out using magnesium sulfate, trisodium citrate, and sodium chloride. This method was assessed by performing recovery tests of chicken muscle, duck muscle, egg, and raw milk spiked with 20 new target analytes at concentrations of 10 and 100 µg/kg. According to this method, 17 out of 20 target analytes satisfied the guideline criteria in chicken muscle and duck muscle, and all 20 target analytes met the criteria in egg and raw milk. The limit of quantification was less than MRLs for all analytes. Residues were detected in 4 out of 99 samples and analyzed using the validated method, finding that the levels of all residues were lower than the limits of quantification. These results suggest that continuous monitoring for a new trend of veterinary drugs is necessary.