Comparative determination of anthocyanins in marasca sour cherry juice using different methods

Antocijani su značajna skupina fenolnih spojeva koji su nosioci karakterističnih boja voća i povrća od crvenih do gotovo tamno ljubiĉastih. Zbog svoje kemijske strukture osjetljivi su na visoke koncentracije kisika, svijetlost, povišenu temperaturu, visoki pH itd. Antocijani su najstabilniji u kiselom području (pri nižim pH vrijednostima stabilnost otopine je veća, a samim time je veći i udio kationa). Za određivanje antocijana koriste se različite metode: pH - diferencijalna metoda, tankoslojna kromatografija, kapilarno-zonska elektroforeza (TLC), tekućinska kromatografija visoke djelotvornosti (HPLC) itd. U ovom radu provedeno je usporedno određivanje antocijana primjenom četiri metode: pH–diferencijalne metode 1 i 2, metode izbjeljivanja bisulfitom te simpl metode. Na temelju dobivenih rezultata može se zaključiti da koncentracija antocijana značajno ovisi o postupku ekstrakcije, ekstrakcijskim otapalima ali i o primjenjenoj metodi određivanja. Najveće koncentracija antocijana u soku višnje maraske određene su u ekstraktima kiselog etanola te primjenom pH diferencijalne metode 1.Anthocyanins are a significant group of phenolic compounds that are carriers of the characteristic colors of fruits and vegetables from dark red to almost purple. Because of there chemical structure they are sensitive to high concentrations of oxygen, light, high temperature, high pH, etc. Anthocyans are stable in the acidic pH range (at low pH, stability of the solution is higher, and thus the greater the proportion of cations). Different methods are used for determination of anthocyanins: pH - differential method , thin layer chromatography, capillary-zone electrophoresis (TLC), high performance liquid chromatography (HPLC), etc. In this paper, a comparative determination of anthocyanins was made by using four methods: pH-differential method 1 and 2, bisulfite bleaching method and simpl method. Based on the obtained results it can be concluded that the concentration of anthocyanins significantly depends on the process of extraction, solvents applied for extraction and extraction method for determination. The greatest concentration of anthocyanins in the sour cherry juice was determined in acidic ethanol extracts and the pH differential method 1 used for determination