Food Hygiene and Safety Science最新文献

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.

Standard curves are used to estimate the concentration of a target substance in food samples and the curves are generally made with the least square method. The least square method is allowed to apply only under the condition that the measurements follow the normal distribution with a constant variance. Actually, however, it is thought that as the measurements of samples are higher, the scattering of the measurements would be also larger. In this study, thus, the effect of the scattering of measured values of samples on the concentration estimation was studied with two normal distribution models with a constant variance and a variance changing to measured values. Measurement data analyzed here were random samples from the normal distributions with various variance. As a result, in the case that the concentrations of the target substance and the measurements were linear, the latter model with the changing variance was statistically more appropriate for the data whose scattering increased with it. However, no remarkable differences were observed between the two models in the standard curves and the estimates from those curves for the measurement sets studied. In the case that the concentrations and the measurements were nonlinear being concave downward and upward, the same results were also observed. These results showed that the model with the changing variance would be more appropriate than the one with the constant variance for various measurement data, while both models could also successfully estimate the concentration of unknown samples.

A quantitative method for determining resorcylic acid lactones (zeranol, taleranol, zearalanone, and zearalenone) in bovine urine using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and evaluated for use in the monitoring of Japanese beef exports to the European Union. This method involves the hydrolysis of conjugates by ß-glucuronidase/aryl sulfatase, clean-up with an immunoaffinity cartridge, and analysis using LC-MS/MS. The developed method was evaluated for zeranol, taleranol, zearalanone, and zearalenone in bovine urine at concentrations of 1 and 2 μg/L. The trueness ranged from 92 to 101%, with intra-day precision of <9% and inter-day precision of <13%. No interfering peaks were observed in the chromatogram near the analyte retention times. This analytical method is valuable for monitoring taleranol, zearalanone, and zearalenone in beef exports to the European Union. The proposed method is also applicable for screening whether zeranol was illegally administered or ingested via feed contaminated with Fusarium toxins, particularly in cases in which taleranol was detected.

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.

An LC-MS/MS method for the simultaneous determination of chloroacetic acid, dichloroacetic acid and trichloroacetic acid (chloroacetic acids) in mineral water (MW) products was developed by modifying the Japanese official method to determine chloroacetic acids. To prevent ion suppression or enhancement caused by sample matrix in LC-MS/MS analysis, the Japanese official method comprises the cleanup step of analytes using cation exchange resin column. The step is time-consuming and costly, and thus the modified method adopted small-volume injection instead of it to prevent matrix effects on ionization, which enabled rapid analysis at low cost. A validation study was performed on the method using MW products which vary in the degree of hardness and contents of carbonate. The trueness, repeatability and reproducibility of the method were estimated to be within the ranges of 95.3 to 104.3%, 1.1 to 2.9% and 2.4 to 6.4%, respectively. The values of every performance parameter met the criteria in the guidelines announced by the Ministry of Health, Labour and Welfare of Japan. A recovery study was performed on 30 kinds of MW products to examine the applicability of the method, and the recovery rate of all target substances ranged from 91 to 108%. Therefore, the modified method is considered to be suitable for the determination of chloroacetic acids in MW products.

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 Codex Standard for Honey adopts diastase activity as an indicator of honey freshness and as a measure to detect overheating during the manufacturing process. However, in some cases a foreign amylase is added to honey to increase its diastase activity. In our previous study, we developed a simple and sensitive method for screening foreign amylases using native polyacrylamide gel electrophoresis followed by activity staining. In this study, to confirm the effectiveness of this method, a collaborative study involving 12 laboratories was conducted in accordance with the AOAC guidelines for qualitative analysis, targeting amylases derived from the Aspergillus and Geobacillus, which were frequently detected in Japan. From the probability of detection (POD) curve confirmed in the preliminary test, three concentrations (low, medium, and high) calculated as diastase numbers were set, and eight samples of each concentration (total of 24 samples) were distributed in a blind manner and evaluated. The results showed that while the POD at the middle level was higher than expected, the method demonstrated sufficient performance to determine the presence or absence of foreign amylase.

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.

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.

We isolated Phytolaccasaponins B, E and G, which are toxic components of Phytolacca americana. Highly purified products were extracted from Phytolacca americana root extract using silica gel, ODS, diol column chromatography. Using these components as analytical standards, we optimized the LC-MS/MS conditions and established 3 components simultaneous analysis method. In recovery tests, the average recovery ranged from 74 to 119%, with a repeatability of 1.0 to 7.1% RSD. Analyses of a 2018 food poisoning specimen indicated 3 toxic components in the leaves and 2 toxic components in the roots. Those findings suggest that the simultaneous analysis method was useful for a food poisoning specimen. These results show that this method is required for identifying food poisoning caused by Phytolacca americana, even when leftovers are unrecognizable or when the poisoning is caused by plant parts other than the roots.