Lycorine and galanthamine are toxic alkaloids found in Narcissus. Using HPLC analysis and quantitative NMR analysis, the degrees of purity of these standard reference materials purchased in 2013, 2019, 2021, and 2025 were calculated and compared. The results showed almost no degradation of any component. However, other findings suggest that the lycorine hydrochloride weight changed because of moisture absorption (hydration). This weight change might be avoided by stocking lycorine hydrochloride monohydrate, which is originally hydrated. Maintaining a stock of lycorine and galanthamine reference materials is desirable for facilitating prompt response to food poisoning by Narcissus. Such poisoning incidents have increased rapidly in recent years. If stored properly after purchase according to the method described in the SDS, then the materials will maintain the purity indicated on the label for at least 10 years. They can be used for analysis without other purity measurement.

A collaborative study was conducted by eight laboratories to validate a method for the determination of zearalenone (ZEN) and deoxynivalenol (DON) in silage using LC-MS/MS. Corn silage and whole-crop rice silage were spiked with ZEN and DON at the following levels: 0.2-2.2 mg/kg of ZEN and 1.2-14 mg/kg of DON for corn silage, and 0.48-2.6 mg/kg of ZEN and 0.8-10 mg/kg of DON for whole-crop rice silage. The resulting mean recoveries ranged from 104% to 111% for ZEN and from 97.9% to 107% for DON. The repeatability and reproducibility, expressed as relative standard deviations (RSDr and RSDR), were less than 6.1% and 8.8% for ZEN, and less than 8.3% and 19% for DON, respectively. The HorRat values were less than 0.53 for ZEN and less than 1.2 for DON. These results demonstrated that the method is suitable for the inspection of ZEN and DON in silage.

A validation study was performed on the modified analytical method for the determination of amines (triethylamine: TEA and tributylamine: TBA) content in polycarbonate food apparatuses, containers, and packaging, by using a mass spectrometer (MS) and a tandem mass spectrometer (MS/MS) to obtain higher selectivity, after solving problems such as TEA volatilization and TEA and TBA adsorption on the apparatuses. The repeatability, within-laboratory reproducibility and trueness of the LC-MS method was estimated in the range of 1.0-3.4%, 1.5-4.8%, and 96-98% for TEA and of 1.1-2.4%, 2.4-4.4%, and 96-97% for TBA, respectively. The repeatability, within-laboratory reproducibility and trueness of the LC-MS/MS method was estimated in the range of 1.2-3.5%, 1.7-7.3%, and 96-98% for TEA and of 1.1-2.4%, 2.2-5.7%, and 95-97% for TBA, respectively. These results showed that the method is useful as an analytical method for the determination of amines content.

The characteristics of stochastic and kinetic models were studied on description of the survivor curve of microbes in food during heating. Exponential and Weibull distributions were used in the stochastic models to model the lifetime of cells and exponential and Weibull functions were used in the kinetic models to model the number of survivors. The data were random samples generated from exponential and Weibull distributions, which can be thought to be the lifetimes of microbial cells heated at a given temperature, and microbial survivor data imaginarily produced from previous papers. The stochastic and kinetic models were fit to data with the maximum likelihood method and the least squares method, respectively. Both models successfully described the survivor curves of random sampling data originated from exponential and Weibull distributions. Namely, both models precisely described linear survivor curves and no-linear ones having an upward concave or a shoulder. For microbial data, the kinetics models precisely described a linear and non-linear curve, while the stochastic models precisely described the survivors at early times of heating, but not those at later times. Similar results on the two models were observed in other survivor data as well. The kinetic models showed better performance in fitting the whole survivor curves than the stochastic ones under the present modeling and estimation frameworks.

Histamine (Him), tyramine (Tyr), putrescine (Put), and cadaverine (Cad), known as nonvolatile amines (NVA), have been identified as particular public health risks. We analyzed 102 samples of 64 agricultural products in Japan. Him was present in 12 products, with eggplant, spinach, and tomatoes containing higher concentrations than other agricultural products. Tyr was present in 29 products, the concentration of which peaked at 132 μg/g in hanabiratake mushrooms. Therefore, we think that patients taking monoamine oxidase inhibitors may need to exercise caution when consuming products containing such high Tyr concentrations. Put was present in many items, especially in solanaceous vegetables, with concentrations of 100 μg/g or more in shishito pepper, sweet pepper and sweet corn, while Cad was present in 15 products, peaking at 3.2 μg/g in sweet pepper. The combination of these foods with foods containing high Him concentrations may lead to allergy-like symptoms.

In March 2023, unapproved genetically modified (GM) squashes were discovered in South Korea. These were thought to be GM squash ZW20 and CZW3, which are approved for use as food only in Canada and the United States. Because the safety of ZW20 and CZW3 has not been evaluated in Japan, they must continue to be monitored to prevent their unintentional import. In this study, we developed and validated real-time PCR-based qualitative detection methods for ZW20 and CZW3. We evaluated these two detection methods on the basis of PCR amplification efficiency, limit of detection, specificity, and reproducibility to determine their utility for distinguishing and identifying ZW20 and CZW3. One method detects the zucchini yellow mosaic virus resistance gene (ZYMV-coat protein: ZYMV-cp) sequence present in both ZW20 and CZW3, whereas the other method detects the cucumber mosaic virus resistance gene (CMV-coat protein: CMV-cp) sequence present only in CZW3. Our results showed that the ZYMV-cp and CMV-cp detection methods are highly specific for GM squash ZW20 and CZW3, and are sufficiently sensitive, capable of detecting transgenes with at least 6.3 and 3.1 copies per reaction, respectively. Based on this study, we developed the official detection method for GM squash in Japan by combining the ZYMV-cp and CMV-cp detection methods to discriminate between ZW20 and CZW3, making it useful for monitoring food safety.

Saxitoxin (STX) and its analogues produced by toxic dinoflagellates in marine environments are known as specific voltage-gated sodium channel blockers and can be detected by the mouse bioassay (MBA) that has been used as the official testing method for paralytic shellfish toxin monitoring systems worldwide. Considering animal welfare issues and improved performance of analytical instruments, it would be better to replace MBA with non-animal testing methods such as LC-MS/MS which have been recently reported for the detection of STXs in shellfish. However, STX itself is regulated by the Act on the Prohibition of Chemical Weapons, so the domestic use of the reference material is required with permission from the relevant government department. Therein, nontoxic enantiomeric STX (ent-STX) was developed as an alternative reference material for STX. In this study, the LC-MS/MS method using ent-STX-fortified scallops homogenate was validated in accordance with a previous report and CODEX-STAN 292-2008. The spiked concentrations of ent-STX were set to the regulatory limits of CODEX (0.8 mg of STX-2HCl equivalents/kg) and approximately half of the limits. The calibration standard solutions were prepared by dilution with solvent and non-toxic scallop extract, respectively, and were used to quantify the toxins by absolute calibration method. As a result of the validation, the results with ent-STX were found falling within all the guideline criteria (the trueness, repeatability, within laboratory re-producibility, and minimum applicable range). Moreover, ent-STX was used to confirm and quantify STX in mussels, scallops and noble scallops. The ent-STX was confirmed to be utilized as reference material. However, it can be sometimes detected an unidentified STX analogue in Japanese bivalve molluscs with retention time close to STX under the qualitative and quantitative selected reaction monitoring (SRM) conditions of STX which are often used in the previous reports. To avoid the assignment of the unidentified STX analogue to STX, appropriate SRM conditions of m/z 300.1>282.0 need to be selected.

Ovomucoid is a protein found in egg white and is the major cause of egg allergy. We have been conducting studies on chicken eggs that do not contain ovomucoid (ovomucoid-null: ON eggs) as hypoallergenic eggs and confirmed that the gelling, foaming, and emulsifying properties of these eggs are almost similar to those of control (Ct) eggs and that they are suitable for cooking and confectionery. In the present study, we compared the changes in bacterial counts in ON eggs and Ct eggs in shell eggs, liquid whole eggs, and liquid egg whites with added Pseudomonas fluorescens, Salmonella Enteritidis, and Bacillus cereus and found no tendency for bacterial counts to increase more easily in ON eggs than in Ct eggs. We guessed that ovomucoid does not affect the bacteriostatic properties of chicken eggs, and that ON eggs do not increase microbial risk.

This study investigated the effective detection methods and contamination status of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the surface of commercially available vegetables and fruits. SARS-CoV-2 RNA was detected by quantitative real-time RT-PCR. A comparison of swabbing methods using three types of materials and five wiping techniques revealed the highest recovery rate when using a polyester swab, wiping in four directions and suspending the swab in PBS after each swabbing direction. The recovery rate of the method was 8-26% on the surfaces of five different types of commercially available vegetables and fruits. Examination of effective washing for removing SARS-CoV-2 from the surface of eggplants showed that >90% of the virus could be removed by water wiping or scrubbing. A total of 90 commercially available vegetables (45 cucumbers and 45 tomatoes) purchased between June and October 2023 were tested to determine the status of SARS-CoV-2 contamination. Although the virus RNA was detected from only one cucumber purchased in August, the number of infectious viruses could not be determined. Results demonstrated that commercially available vegetables have low risks as a source of COVID-19 infection. Preventive measures such as practicing appropriate respiratory etiquette may contribute to the prevention of SARS-CoV-2 contamination in food products. Furthermore, washing the produce with water and basic infection control measures, including hand hygiene and mask wearing, are essential to reduce the risk of infection through food.

The detection sensitivity of the protein wiping method based on BCA assay was evaluated for specified allergenic food ingredients. The detection sensitivity was measured when BSA samples and eight specified allergenic food ingredients (shrimp powder, crab powder, walnut paste, wheat flour, buckwheat flour, liquid egg, milk, and peanut powder) were applied to 25 cm2 stainless steel surfaces, dried, and subsequently wiped off with a swab. The visually detectable limit was determined to be 2-2.25 μg using a BSA solution as the standard, with an absorbance of approximately 0.3 at 562 nm. Test areas with low (2.5 μg/25 cm2), medium (5.0 μg/25 cm2), and high (7.5 μg/25 cm2) contamination levels were prepared, and recovery tests were performed using the protein wiping method. The measurement error was within ±0.03. Moreover, the recovery rate from swabs was observed as 78.2-94.4%. Recovery tests for eight specified allergenic food ingredients showed the ability to detect the ingredients when >10 μg of material was applied to the test surface. This study suggested that the protein wiping method is useful for cleanliness control to prevent cross-contact of allergens in the food manufacturing environment.