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

Validation and verification of cleaning and inspection methods are essential in order to prevent the spread of allergens via cross-contact. Among the hygiene monitoring tests used onsite, the ATP test is rapid and provides quantifiable results. Nevertheless, since a wide variety of food contains 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 to those of the other on-site used hygiene monitoring tests: the conventional ATP test with similar sensitivity for ATP, the protein swab test that detects as little as 50 mg protein, and the lateral flow immunoassay (LFI). The A3 test demonstrated lower detection limits than those of 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 stainless steel model in fish and meat revealed that the A3 test is efficient in verifying the levels of remaining food debris. LFI displayed the best sensitivities for 10 of 14 foods; however, for some specific allergens, is not commercially available, but 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 processed grains except for wheat flour and buckwheat. Undoubtedly, a field study in a food processing plant demonstrated that the amount of both A3 and milk protein (ELISA) considerably decreased as the cleaning steps progressed. Therefore, the A3 test is effective in detecting the risk for allergen cross-contact after inadequate cleaning.