No abstract

No abstract

No abstract

Shared equipment in industrial food manufacture has repeatedly been described as a potential source of unlabeled food allergens, i.e., hidden allergens. However, the impact of shared equipment on allergen cross-contamination is basically unknown. Therefore, we sought to investigate systematically the extent of hazelnut cross-contamination in fine bakery wares as a model. A product change from cookies with 10% hazelnut to cookies without hazelnuts was simulated on pilot plant equipment. The extent of hazelnut cross-contamination (HNCC) was analyzed by enzyme-linked immunosorbent assay (ELISA) for each production device (kneaders, rotary molder, wire cutting machine, and steel band oven) and various cleaning procedures used between products. The experiments were performed repeatedly with finely ground hazelnuts and with roughly chopped hazelnut kernels. Cross-contamination from chopped kernels was distributed statistically but not homogeneously, and sampling and analysis with the ELISA was therefore not reproducible. Further analysis concentrated on homogenously distributed HNCC from ground hazelnut. Apart from product changes without intermediate cleaning, the highest HNCC was found after mechanical scraping: Up to 100 mg/kg hazelnut protein was found in the follow-up product after processing by one machine. After additional cleaning with hot water, the HNCC decreased regardless of the processing device to levels at or below 1 mg/kg hazelnut protein. In our pilot plant study, the application of an appropriate wet cleaning procedure in combination with quantitative monitoring of the cleaning efficiency reduced the hazelnut protein cross-contamination to a level at which severe hazelnut-related allergic reactions are unlikely to occur.

No abstract

No abstract

Lateral flow devices (LFDs) are qualitative immunochromatographic tests for the rapid and specific detection of target analytes. We investigated commercially available LFDs for their ability to detect potentially allergenic peanut and hazelnut in raw cookie dough and chocolate, two important food matrices in the industrial production of cookies. Each three commercial LFDs for the detection of hazelnut and peanut were performed according to the manufacturers' instructions. All LFDs had comparably satisfactory specificity that was investigated with a variety of characteristic foods and food ingredients used in the production of cookies. In concordance with hazelnut-specific enzyme-linked immunosorbent assays (ELISAs), walnut was the most cross-reactive food for hazelnut-specific LFD. The sensitivity was verified in raw cookie doughs and chocolates that were either spiked with peanut or hazelnut between 1 and 25 mg/kg, respectively. Two hazelnut-specific LFDs detected hazelnut at a level of 3.5 mg/kg in both matrices, whereas the third LFD detected hazelnut at a level of 3.9 mg/kg in dough and 12.5 mg/kg in chocolate. Two peanut-specific LFDs detected peanut at a level of 1 mg/kg in both matrices. The third LFD detected peanut at a level of 14.2 mg/kg in chocolate and 4 mg/kg in dough. In conclusion, specific and sensitive LFD were identified for each hazelnut and peanut, having a level of sensitivity that is comparable to commercial ELISA for the investigated matrices. Such sensitive, specific, and rapid tests are useful analytical tools for allergen screening and sanitation in the industrial manufacture of foods.

Food-allergic individuals have to strictly avoid the offending food because no causative immunotherapies are available. Thus, reliable labelling of allergenic ingredients or precautionary labelling of cross-contacts with potential allergens is of major importance. Verification of compliance with labelling requirements and identification of cross-contacts demand test methods that enable the specific and sensitive detection of the analyte. Brazil nut (Bertholletia excelsa) is such a food commodity with allergenic potential. We describe the development of a novel qualitative real-time polymerase chain reaction (PCR) specific for Brazil nut DNA and its comparison with a qualitative commercially available lateral flow device (LFD) that detects Brazil nut protein. Specificity was investigated with 58 foods, and no false-positive reactions were observed in real-time PCR. The sensitivity was investigated with spiked chocolate and incurred dough samples as well as cookies baked thereof. The simultaneous spiking of matrices with identical amounts of Brazil nut and peanut between 5 and 100,000 mg/kg allowed the verification of the spike quality with two peanut-specific enzyme-linked immunosorbent assay. The real-time PCR detected Brazil nut in all three matrices down to the lowest investigated spike level of 5 mg/kg. The real-time PCR results from the analysis of 15 retail samples were confirmed by LFD results and were in concordance with the labelling of products. The real-time PCR showed unparalleled specificity, and primary data indicated potentially quantitative features in spiked and retail samples. Because of entirely reproducible chemistry of this real-time PCR, this is the first generally available Brazil nut-specific detection method with an appropriate sensitivity to help avoid severe allergic reactions for Brazil nut-allergic individuals.