Comparison of cITP and 31 P NMR Methods for Determination of Polyphosphates in Meat Product and Sea Fruits

Phosphates are widely used as additives in different kinds of food, including meat, poultry and seafood. These ions work synergistically with salt and allow meat processors to achieve equivalent water-holding capacity with reduced amounts of salt. Polyphosphates added to meat and seafood products hydrolysed quickly to phosphates and it is difficult to estimation of these compounds (Davis et al. 2004; Sheard & Tali 2004; Jastrzębska et al. 2008). In our work we compared capillary isotachophoresis (cITP) and nuclear magnetic resonance (31P NMR) methods for phosphate ions determination in food samples. Furthermore, the usefulness of the studied methods to monitoring of poly- and pyrophosphates hydrolysis in meat and sea fruits was discussed. The meat products and sea fruit samples purchased from a local market and acquired polyphosphates in composition were used for analyses. The food were minced, homogenised and extracted with redistilled water using an orbital shaker for 45 minutes. The extracts were separated using centrifuge at 9000 rpm for 30 min, followed by double filtration. All extracts were transferred into a 50 ml volumetric flask, made up to the mark and analysed with one-dimensional cITP and 31 P NMR methods. The obtained results for two proposed methods were discussed in respect of the accuracy, precision and compared by F-test and t--test. In concluded, cITP method was simpler, lower time consuming, uncomplicated and economical than 31 P NMR technique. Moreover, permitted on expiration date control by qualitative determination of polyphosphates.