Application of high performance liquid chromatography with refractometric detection method for the identification and quantitative determination of inulin in food products for infants
The aim. Approbation of an inulin determination method on infant food products with a complex matrix without complicated preliminary sample preparation. Materials and methods. The work analyses 16 types of inulin-enriched food products for infants. In order to determine inulin levels, the amount of sugars in a sample was analyzed before and after enzymatic hydrolysis. To analyze the carbohydrate composition, an Agilent 1260 Series (Agilent Technologies, USA) liquid chromatograph equipped with a refractometric detector and a HPLC chromatography column Waters Sugar-Pak (300 mm x 6.5 mm x 10 pim) were used. The parameters of chromatographic separation of sugars: eluent - water with disodium EDTA (0.05 mg/ml); column temperature - 80 ± 5°C; flow rate - 0.5 ml/min; isocratic elution mode. Results. The issues related to the development of a new instrumental method for determining inulin (HPLC-RD) in infant food products are considered. The examined samples contain inulin in sufficient amounts and might serve as inulin sources in infant food products. Conclusion. Thus, the HPLC-RD method for the inulin determination after enzymatic hydrolysis with appropriate modifications is a promising technique for the analysis of polyfructosans in infant food products in the settings of modern test laboratories.