Food Hygiene and Safety Science最新文献

We have developed a rapid genus identification method for poisonous plants. The real-time PCR using the TaqMan^® probe method was employed for detection, with the amplified targets being the "trnL (UAA)-intron" or "trnL-trnF intergenic spacer" regions of chloroplast DNA. The targeted plants were selected six genera (Aconitum, Colchicum, Veratrum, Brugmansia, Scopolia and Narcissus), which have been implicated in many instances of food poisoning in Japan. A tissue lysis solution was used for DNA extraction, which can be completed within approximate 30 min. A master mix corresponding to the tissue lysis solution was used for real-time PCR reagents. As a result, we were able to complete the entire process from DNA extraction to genus identification in 4 to 5 hr. The detection sensitivity was estimated at approximately 1 pg of DNA for all six plant genera. Remarkably, an amplification plot was discerned even with the crude cell lysates of all samples. It was also possible to obtain amplification curves for three plant samples that had been subjected to simulated cooking (boiling). This study suggests that the developed method can rapidly identify six genera of poisonous plants.

Nicotinic acetylcholine receptors (nAChRs) are neurotransmitter receptors found in the nervous system of many organisms, including humans. Neonicotinoid pesticides act as nAChRs modulators that affect neurotransmission. Due to toxicity effects, their use has been restricted. However, a new class of modulators (nAChRMs) have been developed, but analytical methods for the detection of residues of these new pesticides in agricultural crops have not been established. Therefore, this study aimed to develop and validate an accurate determination method for novel nAChRMs, such as sulfoxaflor, flupyradifurone, flupyrimin, and triflumezopyrim in brown rice using liquid chromatography with tandem mass spectrometry (LC-MS/MS). The method was applied to commercially available brown rice samples from Tokyo, Japan. Target analytes were extracted with acetonitrile, cleaned with GC/PSA, and then cleaned again with MonoSpin PBA. In accordance with the method validation guidelines for residual pesticides in foods, the performance characteristics were evaluated, with trueness ranging from 86.3% to 98.2%, repeatability of less than 6.5% relative standard deviation (RSD), and within-laboratory reproducibility of less than 6.5% RSD. These results indicate that the developed method can be applied to residue surveillance of target analytes using solvent standard calibration curves. By applying the developed method to 53 brown rice samples commercially available in Tokyo, sulfoxaflor residues were found in two samples at concentrations of 3.7 and 21.9 ng/g. This is the first report of the detection of sulfoxaflor residues in domestic agricultural products.

A method for analyzing tetrodotoxin (TTX) in miso soup samples was proposed. The samples were purified using strong cation exchange solid-phase extraction and analyzed by liquid chromatography-tandem mass spectrometry. The recovery of TTX was considerably influenced by the salt concentration in the loading solution during purification. It was observed that diluting the loading solution to reduce the salt concentration helped to maintain the recovery rate during the washing step. However, during the loading step, the benefit of dilution in improving recovery was not evident, as the enhanced retention on the solid phase caused by dilution was counteracted by losing TTX with the increased volume of the loading solution, which led to enhanced elution. This suggests that the volume of extraction solution used in the loading process is crucial in determining the recovery rate. Additionally, the use of volatile ammonium acetate as the elution solvent was explored to optimize conditions for effective recovery. Testing this method on miso soup samples with varying miso types, salt concentrations, and TTX levels resulted in consistently high recovery rates of>80%.

Thiouracil (2-thiouracil) is a thyrostat used to promote weight gain in cattle. However, its use is prohibited within the European Union (EU), necessitating the monitoring of its presence in bovine urine for beef exports to the EU. In this study, we present the development and validation of a quantitative method for the determination of 2-thiouracil, 4-thiouracil, and 6-methyl-2-thiouracil in bovine urine using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This method involves stabilizing the analytes by adding hydrochloric acid and ethylenediaminetetraacetic acid to the sample, followed by derivatization with 3-iodobenzyl bromide, cleanup with a divinylbenzene-N-vinylpyrrolidone copolymer cartridge, and subsequent LC-MS/MS analysis. The developed method was validated for determination of 2-thiouracil, 4-thiouracil, and 6-methyl-2-thiouracil in bovine urine at a concentration of 10 μg/L. The trueness ranged from 94 to 97%, with intra-day precisions below 5% and inter-day precisions below 8%. No chromatographic interference was observed near the analytes' retention times. This analytical method is particularly valuable because it can determine whether 2-thiouracil was illicitly administered or ingested via feed containing plants of the Brassicaceae family, by confirming the presence of 6-methyl-2-thiouracil or 4-thiouracil alongside 2-thiouracil in bovine urine.

We conducted a comprehensive survey of Foods with Function Claims (FFC) submitted from April to August 2022 to examine the scientific reliability of the systematic review (SR), which is the basis for functional claims. The results of the review of 611 functional claims for 398 products showed that there were 121 functionally active substances and 87 health claims (Hc) that were labeled, with some functionally active substances having multiple functions. SRs, meta-analyses, and clinical studies were submitted as the basis of functionality for 87%, 10%, and 3% of the reports, respectively. Of these SRs, 39% of the SRs included a single paper. In 67% of the SRs with a single paper included, some of the authors of the included paper and the person who conducted the SR had the same affiliation, which raises concerns about conflicts of interest. The median of clinical trial participants in papers included for SR was relatively small, 38, and the smallest total number of SRs was 6. Thus, it was shown that there are many SRs for FFC that are based on only a single paper or a small-scale clinical trial and that lack reliability as scientific evidence.

Processed foods containing soybean or maize are subject to labeling regulations pertinent to genetically modified (GM) foods in Japan. To confirm the reliability of the labeling procedure of GM foods, the Japanese standard analytical methods (standard methods) using real-time PCR technique have been established. Although certain DNA extraction protocols are stipulated as standard in these methods, the use of other protocols confirmed to be equivalent to the existing ones was permitted. In this study, the equivalence testing of the techniques employed for DNA extraction from processed foods containing soybean or corn was conducted. In this study, the equivalence testing of the techniques employed for DNA extraction from processed foods containing soybean or maize was conducted. The silica membrane-based DNA extraction kits, GM quicker 4 and DNeasy Plant Maxi Kit (Maxi Kit), as an existing method were compared. GM quicker 4 was considered to be equivalent to or better than Maxi Kit.

We developed a simultaneous determination method for the environmentally persistent organochlorine pesticides aldrin/dieldrin, γ-BHC, DDT, endrin, and heptachlor in beef products. In the method, we adopted incremental reduction for sample collection in order to improve the uniformity of the samples. In incremental reduction, a sample was ground and spread to an even thickness, divided into sections, and collected in an equal amount from each section. After extraction with an acetonitrile/ethanol mixture (1 : 1 v/v), sample clean-up was performed by refrigerated centrifu-gation and solid-phase extraction. This process was easy and did not require gel permeation chromatography. The sample was analyzed by GC-MS. A validation study of the development method showed that the tested pesticides met the target values indicated in the validity evaluation guideline.

Some microorganisms, including lactic acid bacteria (LAB), can bind to mycotoxins. Its binding ability is useful for mycotoxin mitigation. Conventionally, the binding assay for this ability of microorganisms to mycotoxins has been performed by the so-called in vitro assay. We previously reported that Lactococcus lactis isolated from cucumber had the ability to bind to aflatoxins using the in vitro assay., However, this is an indirect method by which binding ability is estimated from the mycotoxin residue in supernatant after some processes such as mix, incubation, and centrifugation and it takes time. In the present study, we developed a direct and rapid assay to assess their binding ability using a surface plasmon resonance imaging (SPRi) instrument. It could observe the binding ability as a visual image in real time. The efficacy of this SPRi assay was compared with the in vitro assay. Aflatoxin M₁-bovine serum albumin conjugate (AFM₁-BSA) and deoxynivalenol-BSA conjugate (DON-BSA) were immobilized on the surface of the sensor prism in SPRi assay. The above L. lactis was used to prove the binding ability to the aflatoxin. In vitro assay showed that the binding ratio to AFM₁ was higher than that to DON in both live bacterial cells and heated cells. In the SPRi assay, the binding of live cells to AFM₁ was confirmed by % of the refractivity change (%ΔR) and visual imaging in real-time. The %ΔR of DON was poor, and no visual image was recognized. On the other hand, the heated cells did not bind to any mycotoxins. The results indicate that the SPRi assay can monitor the binding ability of live cells more rapidly and simpler than in vitro assay. It would be a useful tool for the selection of beneficial mycotoxin-detoxifying LAB.

Mysids are small crustaceans that are closely related to shrimp/prawns and crabs but not subject to food allergen labeling requirements for raw materials. In the past, a processed food that contained Japanese smelt (wakasagi) was suspected of producing a false-positive result in shrimp/prawn and crab allergen test because of the presence of consumed mysids. However, there was no reported methods to confirm mysid presence. Therefore, we developed a PCR method to detect mysids. The developed PCR method had high specificity for a mysid species, with no amplification observed from samples of shrimp, crab, krill, mantis shrimp, or the meat of Japanese smelt. In addition, DNA extracted from the internal organs of Japanese smelt was amplified by this PCR method, and sequencing revealed mysid DNA. This confirmed that mysids remained in the internal organs of Japanese smelt following consumption. This PCR method for mysid detection even amplified Japanese smelt-containing processed food samples that were suspected to have produced a false-positive result in shrimp/prawn and crab ELISA. Thus, this PCR method would enable to detect such false positives are caused by mysid contamination.

For Omphalotus japonicus, the coloring molecule was found and characterized using a simple method of identification with a color reaction. The compound that chang color under basic conditions was isolated from a methanolic extract of O. japonicus by liquid-liquid extraction. That compound was identified as thelephoric acid by various spectrum analyses. Color reaction by a beam reagent (5 w/v% potassium hydroxide ethanolic solution) and UV-Vis absorption of an ethanolic solution of thelephoric acid coincided with those of an ethanolic extract of O. japonicus. We conducted LC-MS/MS analyses of all four mushroom species (O. japonicus, Sarcomyxa serotina, Pleurotus ostreatus, and Lentinula edodes). Results demonstrated that thelephoric acid was detected only in O. japonicus. These findings indicate thelephoric acid as a coloring molecule for the identification method described above. This method is useful for distinguishing O. japonicus among other edible mushrooms having similar appearance.