Food Hygiene and Safety Science最新文献

A simple and rapid analytical method was developed for simultaneous detection of fumigants in powdered infant formulas. The QuEChERS extraction technique (EN 15662:2018) combined with liquid chromatography-tandem mass spectrometry enabled the preparation of test solutions by simple dilution without the need for purification using a solid-phase column. As a result of concurrent recovery test, two analytes-metoxadiazone and cyphenothrin-for nine samples (four infant formulas, four follow-up milks, and one hydrolyzed milk) met the management criteria of the guideline for validity assessment by the Ministry of Health, Labour and Welfare in Japan. Thus, The developed method was demonstrated to be suitable for rapid and simultaneous determination of fumigants in powdered infant formulas.

In allergen testing of food products, external quality assessment (EQA) programs are essential to ensure high-precision detection and the reliability of results across testing laboratories. However, conventional spiked samples may not sufficiently reflect the nature of processed foods. Therefore, this study examined the applicability of EQA programs using actual food samples that reflect real-world conditions. Twenty-four commercially available food samples were screened using the ELISA method. A coleslaw dressing (CoD) containing 33.1 μg/g of egg-derived protein which is closest to the labeling reference value of 10 μg/g, was selected. The CoD was diluted with egg-free CoD, resulting in a mean concentration of 10.4±0.6 μg/g (RSD 5.3%).Based on this result, approximately 2 kg of an incurred sample (Sample 1) was prepared for a sample in the pilot study for the EQA program, targeting a concentration of 10 μg/g, and its homogeneity and stability were confirmed. A conventional spiked sample (Sample 2) was also prepared with equivalent quality. A pilot study for the EQA program was conducted with 22 institutions. By using two kinds of ELISA kits, the average concentration was 11.9 μg and 9.7 μg for Sample 1 and 8.6 μg/g and 9.3 μg/g for Sample 2. The performance evaluation using robust statistical methods indicated that nearly all measurement results from the institutions fell within the control limits, suggesting that the incurred sample is beneficial as a test material for the EQA program. These results suggest that EQA programs using incurred samples can contribute to improving the reliability of egg allergen testing in food safety management.

This study proposes a method to determine tylosin A in livestock products and tylosin A and B in honey using LC-MS/MS. The chilled samples were homogenized with a chilled mixture of ethanol and 20% (v/v) acetic acid (1 : 1, v/v),which were further cooled with ice until extraction was initiated. Acetone was used to extract analytes from the samples. These extracts were defatted using n-hexane (this step was omitted for honey) and purified with an octadecyl silylated silica gel cartridge column (Bond Elut C18).HPLC was performed on an Inertsil ODS-4 column using a gradient formed from 0.1% (v/v) formic acid in 5 mmol/L ammonium formate and 0.1% (v/v) formic acid in acetonitrile. Tylosin A and B were detected using tandem mass spectrometry with positive ion electrospray ionization. Recovery tests for tylosin A were performed in bovine muscle, fat, liver, milk, egg, and honey and those for tylosin B were performed in honey. The samples were fortified at the maximum residue limits for the analytes or at quantitative limits: 0.005 and 0.004 mg/kg for tylosin A and B, respectively. The trueness (n=5) of the analytes ranged from 83.1% to 94.9%, with the repeatability of from 0.7% to 7.1%.

We previously developed a real-time PCR-based analytical method to evaluate the thermal history of insects (cockroaches) found in processed foods by measuring the degree of genomic DNA fragmentation. However, in this study, we identified a challenge-postmortem enzymatic DNA degradation occurs in insect bodies, making it difficult to distinguish between heat-induced DNA fragmentation and enzymatic degradation. To address this issue, we developed another approach targeting mitochondrial DNA. The new method may be able to detect DNA fragmentation caused by heating even in the model sample by immersing Periplaneta fuliginosa in curry sauce products at 25℃ for three days, showing resistance to enzymatic degradation. Additionally, considering the limitation of available body parts in practical tests, we divided the bodies of model insects into nine different parts and analyzed them. The improved method showed smaller ΔΔCq values across all body parts, suggesting that the mitochondrial DNA is less prone to enzymatic DNA fragmentation than genomic DNA. The improved method enables the detection of DNA fragmentation at temperatures exceeding 100℃, making it particularly suitable for analyzing insect contaminants in retorted food products.

Food additives are essential for food preservation and quality; however, consumers often perceive them as a potential health risk. The aim of this study was to investigate how educational background and information sources affect perceptions of food additive safety among female students, and to examine the relationship between additive use and product prices. A questionnaire survey was administered to 274 junior high school students, 145 high school students, 96 university freshmen who had not attended specialized lectures, and 137 university students who had attended such lectures. Additionally, 76 pairs of commercial food products were analyzed to compare the prices between those with and without food additives. More than 80% of the respondents expressed interest in food safety, and awareness of food additives was high across all groups, particularly for sweeteners, colorants, and preservatives. Students who had attended food safety lectures were significantly more likely to perceive additives as safe. The main sources of information differed by educational background: school education was the primary source among students who had attended lectures, the internet and social media were most common among those without specialized lectures, and parents and television were the predominant sources of information for junior high and high school students. Products without additives were, on average, 1.6 times more expensive than those with additives, and no price differences were observed across additive types. These findings suggest that specialized food safety education reduces excessive concerns about food additives, whereas "additive-free" labeling contributes to higher product prices by enhancing their perceived value.

The ninhydrin test is a well-known amino acid identification test used in official specification monographs worldwide. Ruhemann's purple (RP) is considered a key product; however, its formation and the color used for identification can be affected by reaction conditions. Since the quality of various reagents used in the ninhydrin test has varied over time, the reaction efficiency can also be affected. In this study, ninhydrin tests for amino acids and related compounds, as specified in Japan's specifications and standards for food additives (JSFA), were performed using high-purity reagents. Results suggested that the colors of the reaction mixtures for several amino acids, including L-asparagine, L-cystine, and L-lysine salts, were not well-suited for their identification tests, potentially leading to misjudgments. To improve the accuracy of the judgment, optimal reaction conditions were investigated using an RP monitoring method via UHPLC/MS/MS. An analysis of the reaction mixtures of L-cystine by HPLC-PDA revealed that sufficient production of RP, relative to other brown-colored by-products, is important for achieving the desired purple coloration. Based on these findings, improved ninhydrin test conditions that can be adopted in JSFA in the future were established. This study provides valuable insights into the ninhydrin reaction based on theoretical and scientific results and contributes to the improvement of identification tests using the ninhydrin reaction specified by the JSFA.

The prevalence of Anisakis contamination in "ready-to-cook (RTC)" mackerel products distributed in Mie Prefecture, central area of Japan, was examined to assess the risk of anisakiasis. Of 136 mackerel fillets examined, 30 samples (22.1%) were positive for Anisakis larvae. The mackerels caught in the Sea of Japan were higher in frequency of Anisakis contamination (41.4%) compared with those from the Pacific Ocean (7.7%) (p<0.01). Number of Anisakis larvae isolated from RTC mackerel fillets was 169, of which 147 (87.0%) were still alive. Around a half of the Anisakis larvae in mackerel fillets were localized in the mid-part of the abdominal side. Two mackerel species were commonly distributed in Japan, however, Anisakis contamination was mainly observed in Scomber japonicus, but rare in S. australasicus. These findings suggest that the risk of anisakiasis transmitted through RTC mackerels might not be low, however, the risk seems to vary depending on the mackerel species, seasons, fishing grounds, and also distribution of fish products.

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 (RSD_r and RSD_R), 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.

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.

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.