AOAC 133rd Annual Meeting - Final Program

Poster Abstracts | Monday

Presenter: Reiko Adachi, National Institute of Health Sciences, Kawasaki, Japan, Email: akasaka@nihs.go.jp P-M-069 Masayoshi Tomiki , Kenichi Aburatani , Hirotoshi Doi , Kazuhiko Kuroda , Morinaga Institute of Biological Science, Inc., Yokohama, Japan Validation Study of the Crustacean ELISA Kit in Highly Processed Foods Crustacean is widely used in processed foods and it is one of the more common allergic ingredients. In 1999, the Joint FAO/ WHO Codex Alimentary Commission agreed to label eight kinds of foods that contain ingredients known to be allergens that included crustacean. According to the recommendation, in many countries including the United States, European Union (EU), Canada, and Australia/New Zealand, crustacean labeling has been mandatory. Also, in Japan, the ministry ordinance has been mandatory that crustacean would be appropriately labeled. Despite the labeling precautions, crustacean remains quite dangerous, as they are often present in commercial foods as a hidden allergen due to cross-contamination during food process- ing. In most factories, many different products are manufactured with various ingredients, as they sometimes even run on the same production line. In addition, heat-treated protein of crustacean is normally difficult to detect by antibody by denaturing target protein. Therefore we developed a reliable ELISA kit to detect crustacean protein in processed foods exactly by combining special extraction buffer and antibody. We validated limit of detection, limit of quantification, recovery of incurred and spiking matrices of the crustacean ELISA in various processed foods. Presenter: Masayoshi Tomiki, Morinaga Institute of Biological Science, Inc., Yokohama, Japan, Email: m-tomiki-aj@morinaga.co.jp P-M-070 Katherine Ivens , Chung Cho , Eric Garber , U.S. Food and Drug Administration, College Park, MD, USA Cross-Reactivity of Chili Peppers Using the xMAP ® Food Allergen Detection Assay (xMAP ® FADA) The xMAP ® Food Allergen Detection Assay (xMAP ® FADA) is a unique and powerful analytical method for simultaneous detec- tion of crustacean, egg, gluten, milk, peanut, sesame, soy, and 9 tree nuts. Except for crustacean, the use of multiple antibod- ies for each allergen permits the calculation of complimentary antibody ratios, allowing positive results to be distinguished from cross-reactivity with homologous proteins. The xMAP ® FADA was used to analyze common botanical ingredients in dietary supplements and spices. These commodities often contain homol- ogous proteins that cross-react with the antibodies and in ELISAs, potentially generating false positives. The assay’s combination of high sensitivity, ability to distinguish between cross-reactive homologues, and ability to quantify the presence of any of the 16 targeted analytes develops a detailed picture regarding the possible presence of food allergens in these botanicals. Analyses were conducted of 27 chili peppers, and intrinsic cross-reactivity was observed with Brazil nut, cashew, hazelnut, pistachio, and walnut antibodies. Laboratory-ground chilis exhibited lower

detection of fish to protect sensitized consumers. Immunoassay detects specific protein through antigen-antibody interaction and can be converted to a simple lateral-flow assay. Because of sheer diversity of fish species and diverse processing conditions, the major difficulty of fish immunoassay development is a lack of marker protein to indicate the presence of fish. The objec- tives of the study are therefore to investigate the effects of food processing on fish muscle proteins and identify a suitable marker protein. The muscle samples from 28 saltwater and freshwater fish species were heated by boiling for observing thermal-stable muscle proteins. To investigate the effect of food processing, muscle cubes were treated with different food processing meth- ods, including boiling, baking, and frying. The muscle proteins were extracted and then separated by gel electrophoresis. The major thermal-stable proteins among 28 fish species were identified as tropomyosin (38-36 kDa), collagen (180 kDa) and myosin (25-10 kDa) by using LC-MS/MS. The 38-36 kDa protein abundantly appeared in the samples of 28 fish species and showed the resistance to the food processing. Based on the thermal-stability and abundance, the identified 38-36 kDa protein (fish tropomyosin) can be a marker protein for the detec- tion of fish. Presenter: Yi-Tien Chen, Taipei Medical University, Taipei City, Taiwan, Email: ychen35@gmail.com P-M-068 Reiko Adachi , Norimasa Tamehiro , Kazunari Kondo , National Institute of Health Sciences, Kawasaki, Japan; Akiko Miyazaki , Satoshi Watanabe , Takashi Hirao , House Foods Group Inc., Yotsukaido, Japan Interlaboratory Validation of Real-Time PCR Methods for the Detection of Wheat, Buckwheat, and Peanuts in Processed Foods In Japan, the labeling of foods containing wheat, buckwheat, and peanuts is mandatory. According to the official Japanese methods for detecting food allergens in processed foods, ELISA methods are used for quantitative screening, while PCR methods are further used as qualitative confirmation tests for positive ELISA results. However, these PCR methods are occasionally unable to detect allergens in some highly processed foods. Therefore, we developed extremely sensitive qualitative real-time PCR methods to detect the presence of wheat, buckwheat, and peanuts in processed foods, which we reported at the AOAC Annual Meeting in 2018. In this study, an interlaboratory valida- tion involving 11 Japanese laboratories was performed to verify these real-time PCR methods. We prepared six model processed foods (rice gruel, mixed juice, instant miso soup, tomato pasta sauce, freeze-dried vegetable soup, and chicken meatballs with vegetables) either containing wheat, buckwheat, and peanut powder at each protein concentration of 10 μg/g (the thresh- old level for allergen labeling in Japan) or not containing the allergen powder. Genomic DNA was then extracted from each food. For all three allergens, the real-time PCR method resulted in a correct decision rate of 100% for both positive and nega- tive samples. This suggests that these real-time PCR methods are reliable for detecting the presence of wheat, buckwheat, and peanuts in processed foods.

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