Evaluation of Aegys MI 600 Fourier Transform Infrared Milk Analyzer for Analysis of Fat, Protein, Lactose, and Solids Nonfat: A Compilation of Eight Independent Studies

Abstract

Abstract The Aegys Mi 600 Fourier transform-infrared milk analyzer was evaluated for performance in 8 independent laboratories in Europe, the United States, and Australia. This instrument, equipped with a mid-infrared source, a temperature-controlled transmission flow cell or cuvette, and detection device, uses interferometry for wavelength generation; multilinear regression was used to create calibration equations for measurement of fat, protein, lactose, and solids nonfat. Each instrument was tested independently for various performance criteria including but not limited to accuracy in calibration and validation, repeatability, and purge efficiency. Mean difference for accuracy and standard deviation of differences for accuracy observed in each laboratory were well within AOAC requirements (<0.05 and <0.06%, respectively) as were the mean of diffferences for repeatability and the standard deviation of differences for repeatability (<0.02 and <0.02%, respectively). Observed purge efficiency was better than 99.0%. In addition, zero stability, instrument reproducibility over 5 days without recalibration, and homogenization efficiency were successfully tested. On the basis of the results, each instrument tested was approved for use for milk payment and/or dairy herd improvement in the country in which it was tested. The results demonstrate that the Aegys Mi 600 meets the requirements of the AOAC Official Method 972.16. The midinfrared spectroscopic method for determination of fat, lactose, protein, and solids in milk has been modified and adopted revised first action by AOAC INTERNATIONAL.