LAUSR

BACKGROUND The BIOFISH 300 HIS method for the quantification of histamine in fish and fish products was validated by the AOAC Research Institute and granted Performance Tested MethodSM certification in 2016. The method is based on the use of an electrochemical reader (BIOFISH 300 device) together with disposable gold electrodes (Biotest) modified with a specific enzyme that oxidizes the histamine molecules and produces a detectable and quantifiable electric current signal. It was validated for raw fish (tuna, mackerel, sardine, and anchovy), cooked fish (tuna), canned fish (tuna in water, tuna in oil, mackerel in tomato sauce, and pickled sardine), and salted fish (canned salted anchovy). The validated ranges were 30-150 mg/kg histamine for canned salted anchovy and 10-200 mg/kg histamine for all other matrices. OBJECTIVE The objective of the present report is to validate some method modifications, namely the use of a new reader (BIOFISH 3000), the inclusion of new quantification ranges, new matrixes in the certified claims, a histamine reference solution (Verifying Solution) that will enable the user to perform a system verification, and also the inclusion of the kit ASC1-10 for the elimination of ascorbic acid from sample extract. METHOD New quantification ranges can be obtained by diluting the sample appropriately into the measurement cuvette, thereby adjusting the concentration to the internal calibration range of the device. New matrixes such as fish meal, preserved salted anchovy, and fish with added ascorbic acid were validated. The new digitalized reader enables new functionalities such as the use of an intuitive app and cloud storage of the results, with no changes in the data acquisition and processing. As the use of the new reader does not imply any change at the electrochemical readout level, all assays were performed using the BIOFISH 3000 device. RESULTS The method was shown to be linear in all the quantitation ranges configured. Accuracy and recovery studies over a wide range of matrices show that the method yields comparable results to the reference method used. Stability and product consistency testing of kit components demonstrated that the system produces accurate results when expiration dates from the manufacturer are met.