Isolation and Characterization of Starch from Different Potato Varieties

U ovom diplomskom radu provedena je izolacija i karakterizacija škroba iz različitih sorti krumpira. Najprije je uzorcima krumpira određen osnovni kemijski sastav, a zatim se u laboratorijskim uvjetima napravila izolacija. Izolirani škrobovi su osušeni, a zatim usitnjeni i prosijani kroz sito otvora 400 μm. Dobivenim uzorcima određeno je sljedeće: osnovni kemijski sastav, boja, termofizikalna svojstva, kapacitet bubrenja i indeks topljivosti. Rezultati su pokazali da je najmanji sadržaj škroba imala sorta krumpira SL 13-25, a najveći sadržaj škroba sorta Stilleto. Sadržaj proteina, masti, pepela i sirovih vlakana je relativno nizak, što ukazuje na visoku čistoću svih izoliranih škrobova. Vrijednosti L* parametra za sve škrobove su blizu 100, što označava jako bijelu boju, a razlike između tih vrijednosti su male, pa je i razlika u boji škrobova teško uočljiva. Prijelazne temperature i entalpije retrogradacije su niže u odnosu na temperature i entalpije želatinizacije. Povišenjem temperature raste kapacitet bubrenja kao i indeks topljivosti kod svih uzoraka.In this graduate thesis, the isolation and characterization of starch from different potato varieties was carried out. First, the basic chemical composition of potato samples was determined, and then the isolation was done in laboratory conditions. The isolated starches were air-dried, then crushed and sieved through a 400 μm sieve. The basic chemical composition, color, thermophysical properties, swelling power and solubility index were determined in the obtained samples. The results showed that the potato variety SL 13-25 had the lowest starch content, and the Stilleto variety had the highest starch content. The content of protein, fat, ash and crude fiber is relatively low, which indicates the high purity of all isolated starches. The values of the L* parameter for all starches are close to 100, which indicates a very white color, and the differences between these values are small, so the difference in the color of the starches is hardly noticeable. The transition temperatures and enthalpies of retrogradation are lower compared to the temperatures and enthalpies of gelatinization. Increasing the temperature increases the swelling capacity as well as the solubility index of all samples