Determination of phytic acid and iron in legumes

Fitinska kislina je naravna spojina, ki pri fizioloških pogojih tvori slabo topne komplekse s večkratno nabitimi kationi in tako zniža njihovo biodostopnost. Pomembno je poznati sestavo živil in vlogo posameznih sestavin za prilagoditev diete in morebitne modifikacije živil. Namen te magistrske naloge je razviti primerno metodo priprave vzorca za določitev vsebnosti fitinske kisline s potenciometrično titracijo. Priprava vzorca, različne vrste stročnic, je temeljila na obarjanju železovega fitata in nato kisanjem z ionsko izmenjevalno kolono. Poleg tega sem v stročnicah določila vsebnost železa z atomsko absorpcijsko spektroskopijo z metodo umeritvene premice in standardnega dodatka. Preverila sem tudi vpliv fitinske kisline na to določitev in ugotovila, da na določitev železa bolj vpliva pH, kot prisotnost fitinske kisline.Phytic acid is a natural occurring compound that forms insoluble complexes with many polyvalent cations and therefore lowers their bioavailability. The knowledge of foodstuff components and their role is essential for potential adjustments to the diet or modification of said foodstuff. The aim of this master thesis is to develop suitable sample preparation for determination of phytic acid content in legumes with potentiometric titration. The sample preparation is founded on precipitation of ferric/ferrous phytate and additional protonation by ionic exchange column. In addition to phytic acid determination, I also examined the influence of phytic acid on iron determination by atomic absorption spectroscopy and then analysed legumes for iron. I established that beside phytic acid, pH value is of the most importance when determining the iron content. I also compared results that I got using method of calibration curve and standard addition