Comparison of Detection Limits for Allergenic Foods between Total Adenylate (ATP+ADP+AMP) Hygiene Monitoring Test and Several Hygiene Monitoring Approaches

Abstract

Validation and verification of cleaning and inspection methods are essential to prevent the spread of allergens via cross-contact. Among the hygiene monitoring tests used on-site, the ATP test is rapid and provides quantifiable results. Nevertheless, because a wide variety of foods contain significant amount of ADP and/or AMP due to the degradation of ATP, the ATP+ADP+AMP (A3) test is preferred for detecting food debris. Hence, the A3 test may be valuable in screening food debris that may contain residual allergens. In this study, the detection limits of the A3 test for 40 foods that are regulated in several countries as allergenic were compared with those of the other hygiene monitoring tests used on-site: the conventional ATP test with similar sensitivity for ATP, the protein swab test that detects as little as 50 μg of protein, and the lateral flow immunoassay (LFI). The A3 test demonstrated lower detection limits than did the ATP test. The detection sensitivity of the A3 test was greater than that of the protein swab test except for its use on gelatin (extracted protein). The cleaning validation performance using a stainless steel model in fish and meat revealed that the A3 test is efficient in verifying the levels of remaining food debris. Although LFI displayed the best sensitivities for 10 of 14 foods, it is not commercially available for some specific allergens; however, the A3 test can detect such food debris. Moreover, the detection limits of the A3 test were preferable or comparable to those of LFI for crustacean shellfish and for processed grains, with the exception of wheat flour and buckwheat. A field study in a food processing plant demonstrated that the amount of both A3 and milk protein (enzyme-linked immunosorbent assay) considerably decreased as the cleaning steps progressed. Therefore, the A3 test is effective in detecting the risk for allergen cross-contact after inadequate cleaning.