The committee for the National Institute of Health Sciences Japan—The Methods for the Microbiological Examination of Foods (NIHSJ-MMEF). aims to develop domestic standard methodologies for food microbiological testing that conforms with internationally recognized standards. In this study, we developed a new qualitative detection method for Clostridium botulinum (NIHSJ-20TS) based on ISO/TS 17919: 2013 and validated its performance through interlaboratory study. To facilitate interlaboratory studies under stringent legal regulations, a detailed protocol for inoculum preparation was provided instead of distributing inoculated samples. In addition, we evaluated commercial DNA extraction kits as a simpler alternative to the conventional Cetyltrimethylammonium bromide (CTAB) method. The collaborative study plan was optimized as a minimal yet effective plan to verify the reproducibility and applicability of the method. After completing the validation study, the level of detection 50% (LOD₅₀), a proposed reference value for implementation verification described in ISO 16104-3:2021, was evaluated. We believe that NIHSJ-20TS may facilitate the international acceptance of microbiological testing results generated in Japan.

In Japan, several standard methods have been established and published for detecting microbes from foods by “the Committee of the Methods for the Microbiological Examination of Foods (NIHSJ-MMEF)” since 2005. From the results of the Committee’s activities, five of them became official Japanese methods including NIHSJ-08 and NIHSJ-09 which were first published in 2011 and 2014 based on ISO 11290-1 and ISO 11290-2 with some modifications. In this study, a working group consisting of five institutions was established to analyze that the modifications using CHROMagar ^TM Listeria was valid; the method developed was applicable for some Japanese foods such as minced tuna; and what the estimated limit of detection at 50% probability (eLOD₅₀) were. The eLOD₅₀ values were 0.744 CFU/25g for detection from Half-Fraser broth and 1.11 CFU/25 g for detection from Fraser broth, respectively. Finally, this study established and validated the parameters necessary for monitoring food contamination with Listeria monocytogenes (L. monocytogenes) in Japan.

To ensure the safety of plastic food utensils, containers, and packaging, migration testing is essential for the qualitative and quantitative analysis of chemical substances that migrate from these materials into foods. In the context of foods with shelf lives ranging from several months to several years, conducting actual long-term migration tests is particularly challenging. It is therefore necessary to establish accelerated test conditions that yield equivalent migration levels. In order to establish such accelerated test conditions, results obtained from long-term migration tests using food-simulating solvents are required. However, when conducting long-term migration tests, concerns arise regarding the spoilage of food-simulating solvents and the adsorption of migrated substances onto the test container. To address these problems, model samples were prepared by incorporating ten substances with a wide range of Log Pow values into eight types of general-purpose synthetic resins. Using four types of food-simulating solvents (water, 4% acetic acid, 20% ethanol, and olive oil), potential methods for long-term migration testing were examined. An analytical approach based on liquid chromatography–tandem mass spectrometry (LC-MS/MS) was evaluated and confirmed to be applicable for use with the various food-simulating solvents. More specifically, in the long-term migration test using water, a decrease in the migration amount of dimethyl isophthalate was observed in high-impact polystyrene and polyamide due to the influence of microorganisms proliferating within the migration solution. It was also demonstrated that the addition of sodium azide is effective in preventing spoilage. Furthermore, it was confirmed that the adsorption of substances with Log Pow values of <6 onto glass containers could be considered negligible. Using the LC-MS/MS-based long-term migration test protocol established in this study, it becomes possible to examine conditions for setting accelerated test parameters.

MT test Immunochromato-PSP had been developed in a collaborative research project. In this kit, the previously developed mouse monoclonal antibody GT-13A designed against GTX2/3 is used. Since STX and its analogs (STXs) are small molecules, a competitive inhibition format with modified-STX is applied. The formation of Avidin Biotin complexes to trap modified-STX on the test line showed interference by the bivalve matrix, so we improved the kit with oligonucleotides trapping complementary strands. The affinity of the GT-13 antibody differs depending on the STX analogs present and does not correspond to relative toxicity. Therefore, it is necessary to accumulate data in advance on paralytic shellfish toxins (PSTs) toxin profiles for the local target species and area. Since this kit is intended to be used in screening, it is necessary to consider a dilution factor that will never lead to a false negative against the regulatory value. Although this kit is qualitative, it can be recorded and compared objectively as semi-quantitative data by imaging and quantifying. It can also be used to determine PSTs presence in seawater samples. In recent years, the problem of PSTs has become more serious in the east and north of Japan. We are considering using the kit for monitoring scallops in one prefecture and have confirmed that some of the samples could be assessed with the kit and applied to screening. However, we also observed transformation of PSTs after the shellfish became highly toxic, limiting the utility of the kit in these cases.

Food Safety Commission of Japan (FSCJ) conducted a risk assessment of cyclopyranil (CAS No. 1651191-47-7), a pyrazolylpyrazole herbicide, based on results from submitted documents. The data used in the assessment include fate in plants (paddy rice), residues in crops, fate in animals (rats), subacute toxicity (rats, mice and dogs), chronic toxicity (dogs), combined chronic toxicity/carcinogenicity (rats), carcinogenicity (mice), two-generation reproductive toxicity (rats), developmental toxicity (rats and rabbits) and genotoxicity. Major adverse effects of cyclopyranil were observed in body weight (suppressed weight gain), the liver (effects including organ weight increases and hepatocellular vacuolation), the kidney (effects including lipofuscin deposition in renal tubules), and the brain (cerebral neuropil and white matter vacuolation in dogs) (Table 1). Adverse effects were observed on neither fertility, teratogenicity, nor genotoxicity. The lowest NOAEL for potential adverse effects after a single oral administration of cyclopyranil was 60 mg/kg bw per day from the result of a developmental toxicity study in rabbits (Table 2). FSCJ specified an acute reference dose (ARfD) of 0.6 mg/kg bw by applying a safety factor of 100 to this NOAEL.