Food Hygiene and Safety Science最新文献

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.

Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli) can colonize the gastrointestinal tracts of broilers, and poultry meat is contaminated with these organisms during slaughter in poultry processing plants. We investigated the relationship between Campylobacter counts in cecal contents of broilers and those in chicken meat at eight chicken processing plants. Ceca and their breast products derived from broilers from 51 flocks were collected. Campylobacter were isolated from cecal contents of 40 (78.4%) flocks. The average number of Campylobacter in the ceca of the Campylobacter-positive flocks was 7.6 1og₁₀ CFU/g. Of 51 chicken breast products, 35 (68.6%) were contaminated with Campylobacter and the average number of Campylobacter was 1.7 1og₁₀ CFU/g. All the Campylobacter-positive products were derived from Campylobacter-positive flocks. The results of this study indicate that there is a weak positive correlation (R=0.37) between the number of Campylobacter in the ceca of broiler flocks and the number of Campylobacter in chicken meat. Of the 14 products with C. jejuni/C. coli counts of 2.0 log₁₀ CFU/g or more, nine (64.2%) were from groups with high Campylobacter (≥ 8.4 log₁₀ CFU/g) in the ceca. The Campylobacter prevalence of products from chicken flocks with C. jejuni/C. coli counts of 6.2 log₁₀ CFU/g or less in the cecal contents have a C. jejuni/C coli contamination rate of 50% (3/6) with a maximum Campylobacter count of 1.4 log₁₀ CFU/g.

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.

The study aimed to evaluate the effect of peracetic acid formulation (PAA) in the cut salads as a model food with different treatment conditions and observed their effect on the shelf life. This study revealed that at 80 ppm PAA, the standard for use on vegetables, showed a temporary and weak bactericidal effect. Additionally, there was no improvement in the shelf life of the cut salad. In contrast, PAA treatment at 240 ppm significantly reduced and suppressed the growth of hygiene indicator bacteria for 7 days. Moreover, no injured bacteria were produced due to proper sterilization. Based on these findings, it is believed that 240 ppm of PAA is suitable for washing cut salads and effective to improve their shelf life.

LC-MS/MS was used to develop a qualitative analytical method for milk, egg, buckwheat, and peanut allergens. The measurement conditions and extraction and trypsin digestion process for protein pretreatment were optimized. A sample spiked with each allergen was analyzed to evaluate the performance of the analytical method, including the extraction process. Repeatability and intralaboratory precision met the target values for all allergens, confirming the stability of the analytical method. Furthermore, the S/N ratio, retention time, and peptide ratio demonstrated the usefulness of the method as a qualitative test. Moreover, for milk and egg allergens, the equivalence of the quantitative values calculated using the developed method to those of ELISA was confirmed; however, this equivalence could not be confirmed for commercially available processed foods and some quality control samples. For buckwheat and peanut allergens, the equivalence of the quantitative values to those of ELISA could not be confirmed in the spiked sample. These findings demonstrate that this analytical method is useful as a rapid and simple qualitative test. It is also an excellent alternative to ELISA as it produces less waste and reduces environmental burden.

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.

Chloropropanols and related substances have received a great deal of attention in the world. Regulation values have already been established in the EU for infant formula. There are several validated analytical methods for these substances, such as the AOAC official method. However, no analytical official method has been established for infant formula in Japan. In this study, the AOAC official method was improved to a more versatile splitless injection method in order to make it feasible for many laboratories. The results of the validation data for the improved method with optimized injection conditions were as follows. The limit of quantification was 10 μg/kg, the recovery rate ranged from 81.6 to 114.5%, and the intermediate precision ranged from 1.6 to 7.6%. These results were adapt to AOAC and EU requirement and demonstrated the good validity of the improved method.

A method for the determination of two kinds of cyanide, namely cyanide ion and cyanogen chloride, in various mineral waters (MWs) has been developed and validated. MWs are varying in the degree of hardness and carbonation. The results of two carbonated MWs obtained through the validated official method for cyanide analysis in tap water did not meet the criteria of the validation guideline for MW in Japan. Furthermore, in the pH adjustment during pretreatment, some MWs did not reach approximately pH 2.4, the level assumed in tap water quality tests. After five-fold dilution of the samples with phosphate buffer, the specified pH value of 2.4 was achieved, leading to the improvements in trueness. The validation tests of the method with the additional dilution step showed the trueness from 93.0 to 103.8%, RSDs of repeatability and within-laboratory reproducibility below 3.83% and 4.68%, respectively. These values fulfill the criteria on both analytes. The developed method indicated the potential applicability for accurate determination of cyanide ion and cyanogen chloride in a range of commercially available MW products.