Naslov
Spektrofotometrijska studija sustava škrob- trijodid
(Spectrophotometric study of starch-triiodide system)

Autori
Karnaš, Maja

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, diplomski rad, preddiplomski

Fakultet
Odjel za kemiju

Mjesto
Osijek

Datum
20.09

Godina
2011

Stranica
36

Mentor
Sak-Bosnar, Milan

Neposredni voditelj
Sakač, Nikola

Ključne riječi
škrob; amiloza; trijodid; spektrofotometrija; botaničko porijeklo
(starch; amylose; triiodide; spectrophotometry; botanical origin)

Sažetak
Starch is a polysaccharide stored in plants as a food reserve. According to its chemical composition it is a mixture of two D- glucose polymers, amylose and amylopectin. When a solution of iodine in potassium iodide (triiodide solution I3- or Lugol solution) is added to a starch solution, intensive dark blue or, rarely, brown coloration appears. This coloration is a result of yielded starch-triiodide complex. Concentration of this complex and thus the concentration of starch can be determined spectrophotometricaly by measuring the absorbance of the given sample. Volume fraction of amylose and amylopectin varies depending on the starch type. Both starch components yield complex with triiodide, amylose yields strong dark blue and amylopectin weak brown complex. Therefore the absorption spectra of starch-triiodide complex can be taken as a parameter for determination of botanical origin of starch, as presented in this research. Noted differences between various starch types are in the intensity of coloration due to complex formation, maximum wavelength of absorbance and the shift of maximum wavelength of absorbance when compared to representative sample.

Izvorni jezik
Hrvatski

Znanstvena područja
Kemija

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