title: Determination of Labeled Fatty Acids Content in Milk Products, Infant Formula and Adult/Pediatric Nutritional Formula by Capillary Gas Chromatography: First Action 2012.13.
abstract: The method described below is intended for the quantification of all fatty acids, including commercially important groups of fatty acids used for labeling reasons (i.e., TFA, SFA, MUFA, PUFA, omega-3, omega-6, omega-9) and/or individual fatty acids (i.e., LA, ALA, ARA, EPA, DHA) in milk products, infant formula and adult/pediatric nutritional formula. These products often contain milk fat and/or vegetable oils, and are supplemented or not supplemented with oils rich in long chain polyunsaturated fatty acids (LC-PUFA). The determination is performed by direct transesterification of ready-to-feed liquid concentrate or powder products, without prior fat extraction. The single laboratory validation (SLV) data was submitted to the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) Expert Review Panel (ERP) for review at the AOAC INTERNATIONAL annual meeting held September 30 to October 3, 2012 in Las Vegas, Nevada. The ERP determined that the data reviewed met the Standard Method Performance Requirements (SMPR 2012.11) set by SPIFAN and was approved as an AOAC Official First Action. The analytical range for SPIFAN samples was between 0.001-7.94 g/100 g reconstituted product, or ready-to-feed liquid. The quantitation limit was estimated as 0.001 g/100 g, while repeatability and intermediate precision were both less than 1.8 % RSD above 0.05 g/100 g, and <3.5% RSD at 0.00 5g/100 g, respectively. Recovery values based on spiking experiments at two different levels of linoleic and linolenic acids ranged from 100.0% to 102.9% for 3 different SPIFAN products. All the parameters evaluated during the SLV were well within the values defined in SMPR 2012.011 (September 2012).