[Secondary Contamination by Wheat Allergens across Cooking Bowls through the Use of Sponge Scourers].

After washing the cooking utensils used to prepare liquid batter, flour may remain in the scrubbing sponge. Secondary contamination of cooking devices with wheat allergens is a concern if such scrubbing sponges are used to clean other equipment. Therefore, in this study, bowl washing with detergent, using a scrubbing sponge was evaluated as a cleaning method following liquid batter cooking. Multiple trials revealed that wheat allergens were transferred from a bowl coated with 10 g of liquid batter to an unused bowl via sponge scrubbing with a positive rate of approximately 80%. Residual batter was observed in the scrubbing sponge after cleaning and rinsing procedures, with a residual rate of about 20%. Detailed observation of the residue revealed that proteins such as gluten were attached to the cell skeleton, and between the skeletons of the sponge, and starch granules were attached to the proteins. Even with sponge rinsing conditions added to the protocol, complete removal of wheat allergen was difficult. These studies indicate that particular scrubbing sponges for cleaning the residual wheat on cooking utensils should be dedicated exclusively in cooking facilities that prepare allergy-friendly-foods to avoid risk of allergen contamination.

Development of a Solid Phase Extraction-Based Method for the Quantitative Analysis of Methylmercury in Soil and Sediment.

A simple, universal method to quantify soil methylmercury (MeHg) is not available. Here, we developed a solid-phase extraction-based method using gas chromatography mass spectrometry. MeHg was purified from the soil matrix using an optimized solid-phase extraction method, which reduced the use of organic solvents and eliminated the requirement for harmful reagents. The sample limit of quantification was 7.5 ng/g. MeHg recovery in the reference samples was 96.2%-102.6%; the intra- and inter-assay coefficients of variation were 3.4%-7.1% and 4.3%-7.1%, respectively, indicating high validation performance. This analysis method is simple as it can be performed using general-purpose reagents and instruments; has a high degree of trueness and accuracy; could be useful for soil MeHg quantification with improved sensitivity; and can provide reliable data to prevent MeHg contamination and improve food safety.

The development of dual-function solid-phase method as extraction and a decomposition reaction media for the determination of a formaldehyde releaser, imidazolidinyl urea, in cosmetics.

In this study, we present a simple method to determine imidazolidinyl urea (IU) in cosmetics using a solid phase as both a decomposition field and an extraction phase. IU is difficult to quantify because it is a mixture of allantoin-formaldehyde condensation products that are easily decomposed to release formaldehyde. In our method, IU is decomposed to allantoin and 1-[4-(hydroxymethyl)-2,5-dioxoimidazolidin-4-yl]urea (4-HU) on an aminopropyl-bonded silica solid phase. Subsequent high-performance liquid chromatography enables quantification of the resulting allantoin and 4-HU. The quantified value was converted to the total allantoin amount on the basis of molecular weight, and the calculated value was compared with that of an IU reference standard to determine the contents. The calibration curves of the decomposed IU as allantoin and 4-HU were both linear over an IU solution concentration range from 0.05 to 0.65% (w/v). The recoveries from lotion, body soap, and conditioners, which contained 0.1%, 0.3%, and 0.6% (w/w) of IU, respectively, ranged from 88.2 to 107.5%. The relative standard deviation values for the recovery tests of six replicates ranged from 1.03 to 6.97%. The intra-laboratory precisions for the lotion and conditioner A containing 0.3% IU were 3.02 and 4.94%, respectively. This method was well validated and would be helpful in determining IU in cosmetic samples.

Comparison between mouse bioassay and HILIC-MS/MS for quantification of paralytic shellfish toxin in Japanese basket clams and mussels caught off coastal Osaka Bay in Japan.

The content and composition of paralytic shellfish toxins (PSTs) in Japanese basket clam (Corbicula japonica) and mussels (Mytilus galloprovincialis) from Osaka Bay, Japan, were investigated using a mouse bioassay (MBA) and hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS), and the association between toxicity values of MBA and HILIC-MS/MS was verified based on research data. The overall toxicity in Japanese basket clam was lower than that in the mussel. The PSTs of Japanese basket clam and mussel consisted mainly of C1, C2, and gonyautoxins 1-4 (GTX1-4) taking toxins compositional differences as mol%. When multiplying the content of different toxins by the toxic equivalent factor (TEF), C2 and GTX1-4 accounted for more than 90% of total toxicity (MU TEF/g) based on the MU TEF score converted by TEF for the two species. The total content of C2 and GTX1-4 converted to toxicity was significantly correlated with the toxicity determined by MBA for the two species (r2 > 0.983). This study provides a suitable and ethical monitoring method to investigate toxicity in bivalves contaminated with A. tamarense by analysis of only predominant toxins, along with reducing use of MBA.

Development of a liquid chromatography-tandem mass spectrometry method for simultaneous quantification of hen's egg white allergens Gal d 1-4 in fresh and processed eggs.

Hen's egg white allergens, namely Gal d 1-4, cause food allergies worldwide and their intake must be strictly controlled by allergic individuals. However, an efficient method for quantifying these allergens is currently unavailable. We aimed to develop an LC-MS/MS method for simultaneous Gal d 1-4 quantification. Purified Gal d 1-4 proteins were trypsin-digested and the resulting peptides used in LC-MS/MS analysis. The limits of quantification were 9.77-39.1 ng/mL. The Gal d 1-4 recovery in fresh and processed eggs was 68.3-121.3%, and intra- and interassay coefficients of variation were 1.5-15.7% and 2.4-38.1%, respectively, indicating high sensitivity, accuracy, and reproducibility. In addition, the high specificity of this method was confirmed by testing 27 other foods. This newly developed method could provide reliable information to the industrial food and clinical fields, facilitating improved quality of life for individuals with egg allergies.

[Reduction of Orange Allergen Cit s 2 Levels in Fresh Orange Juice with Pineapple Bromelain Enzymatic Treatment].

Oranges are consumed worldwide; however, they contain Cit s 2, a major profilin allergen. We aimed to reduce Cit s 2 levels by preparing mixed orange fresh juice with pineapple, as a convenient method for any kitchen. Cit s 2 levels in orange extracts digested with pineapple extract and its protease bromelain were evaluated with quantitative enzyme-linked immunosorbent assay. Cit s 2 levels decreased according to reaction temperature and time, which was inhibited by iodoacetic acid. Treatment with pineapple extract diluted 40-fold and 0.1 mg/mL of bromelain at 37℃ for 30 min contributed to reducing residual Cit s 2 levels below the cut-off of 15%, respectively. Since this condition can increase the proportion of orange juice and reduce the risk of ingesting the pineapple allergen bromelain, it is considered to be more practical. Broad utilization of proteases in hypoallergenic food products is expected following clinical studies for verification.

Concentrations of total mercury and methylmercury in red snow crabs (Chionoecetes japonicus) caught off the coast of Japan.

The total mercury (T-Hg) and methylmercury (MeHg) concentrations in red snow crabs (Chionoecetes japonicus) caught off the coast of Japan were analyzed. The T-Hg concentration ranged from 0.03 to 0.56 mg/kg (mean: 0.21 mg/kg) in the raw muscle, and 0.02 to 0.74 mg/kg (mean: 0.27 mg/kg) in the boiled muscle. The MeHg concentration ranged from 0.04 to 0.54 mg/kg (mean: 0.20 mg/kg) in the raw muscle. The mean ratio of MeHg to T-Hg was 0.88. The crab body weight was found to significantly correlate with the concentrations of T-Hg (r = 0.488) and MeHg (r = 0.490) (p ≤ 0.01). For the general population in Japan, the intake of MeHg from eating red snow crab was estimated to be lower than 0.013 mg/week, which was less than one-sixth of the tolerable MeHg intake (0.08 mg/week).

Characterization of a new illicit phosphodiesterase-type-5 inhibitor identified in the softgel shell of a dietary supplement.

A new sildenafil analog has been identified in the softgel shell of a dietary supplement. The compound was investigated by UV spectroscopy and high-resolution MS analysis, leading to the proposed structure 1-methyl-5-{5-[2-(4-methylpiperazin-1-yl)acetyl]-2-propoxyphenyl}-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one. A synthetic reference compound with the proposed structure was prepared, and the two sets of analytical data were compared, confirming the structure of the new compound. The compound was named propoxyphenyl noracetildenafil from its structure and similarity with the known compound.

ANALYSIS OF WHEAT ALLERGEN DISPERSED IN AIR BY THE ACTION OF THREE TYPES OF FLOUR SIFTER.

BACKGROUND: Since wheat flour, a cause of food allergy, tends to disperse rapidly in air, it can unintentionally mix other foods during the sieving process. Our aim was to analyze the dispersal of wheat flour dust in air in order to prevent unintentional mixing. METHODS: We measured particle size distribution of wheat flour, photographed the scattered flour for 60 seconds every 10 seconds after sieving through three types of flour sifter, constructed a velocity vector diagram of flour dust dispersal by each type of sifter, and measured the distance of wheat allergen dispersal over 20 minutes using a petri dish and immunochromatographic test. RESULTS: The particles were mainly 14.2µm and 60.4µm in diameter and settled at terminal velocities of about 8mm/s and 150mm/s, respectively. Wheat flour particles of more than 60µm (released in air by sifting) dropped mainly in the perpendicular direction, while particles of less than 30µm remained suspended and traveled 5m after sifting by all flour sifters. CONCLUSION: Our results suggested that wheat flour dust dispersed by sifting (regardless of sifter) could unintentionally mix other foods. To prevent contamination, it is necessary to control the flow of air or sift flour in a separate room.

Development of monoclonal antibody-based ELISA for the quantification of orange allergen Cit s 2 in fresh and processed oranges.

The aim of this study was to develop a monoclonal antibody (mAb)-based enzyme-linked immunosorbent assay (ELISA) for the quantification of a major allergen (Cit s 2) in fresh and processed oranges. Purified recombinant Cit s 2 (rCit s 2)-small ubiquitin-like modifier (SUMO) was used for the production of mAbs. In the optimized ELISA, the recovery of rCit s 2 from Navel oranges or orange juice was 107-132%, and the intra- and inter-assay coefficients of variation were 3.1-8.8% and 4.4-11%, respectively. The Cit s 2 content in fresh oranges was determined to be 1,800±430ng/g, while this content was much lower in the processed foods. The developed ELISA demonstrated high reproducibility, sensitivity, and accuracy, and this assay may help individuals with orange allergy by determining Cit s 2 quantities in food products and controlling their Cit s 2 intake.

[A Survey of School Lunch Provision for Elementary School Students with Food Allergy in Seven Cities of Osaka Prefecture].

The number of students with food allergy is currently increasing. Moreover, the unintentional mixing or accidental ingestion of allergy-causing food materials in school lunches has attracted great attention. The aim of this study was to verify the current status of elementary school lunch provision for students with food allergy. We investigated the elementary school lunch services in seven cities in Osaka prefecture. The egg elimination diet was provided in five of the seven cities. In four of these five cities, we did not detect the presence of egg residue either on the surface of various cookware used to prepare the egg elimination diet or in the food itself. In this investigation, the egg elimination diet was provided properly, but we observed differences among the cities in the manual preparation of foods for food allergy diets. To step up these efforts, our results suggest the necessity of preparing a manual to consider individual conditions of school lunch services.

[Allergy due to probable contamination of bread used for school meals with milk].

BACKGROUND: In May 2012, two schoolchildren developed allergic symptoms after eating a school meal of fried bread in Osaka, Japan. One specific raw material, milk, should not be present in fried bread. However, we suspected the unintentional mixing of milk in the bread manufacturing process. Our aim was to verify the reason if this was so. METHODS: We first manufactured bread that contained milk as one of its components. We then thoroughly cleaned the manufacturing line except for the dough divider and, as per the revised instruction manual, continuously manufactured bread that did not contain milk. In this manner, we tried to simulate the conditions at the time of the incident. Casein is a major milk protein. We, therefore, determined casein concentration in the milk-free bread, using casein enzyme-linked immunosorbent assay. RESULTS: We observed casein levels higher than 1000 ppm in the initial lots of breads, but lower levels in the later lots. Casein levels also decreased upon frying of bread. CONCLUSION: High casein levels, which were observed in the earlier lots of breads, were lower in the later lots. In the manufacturing line, the remnants of the bread dough that contained milk presumably got mixed with the dough used in the subsequent manufacture of milk-free bread.