Authors:Miuţa Filip, Mihaela Vlassa, Florina Copaciu and Virginia Coman
The profiles of anthocyanins and anthocyanidins present in berry fruits can be used as fingerprints for the evaluation of authenticity of raw materials, juices, fruit extracts, and food products. The aim of our work was to establish the authenticity of fruit juices from the market according to the label inscription. With this end in view, we used spectroscopic and TLC techniques for the preliminary identification of main groups of anthocyanins and to obtain a fingerprint of each berry fruit used in the preparation of juice. For the same purpose, we achieved a RP-HPLC method for the determination in detail of the composition of natural pigments, such as anthocyanins from alcoholic extracts of colored fruits and anthocyanidins from their hydrolyzed products. The RP-HPLC chromatographic fingerprints gave us the possibility to identify seventeen anthocyanins (glycosylated anthocyanidins) and five major anthocyanidins (delphinidin, cyanidin, petunidin, pelargonidin, and malvidin) from the extracts of colored fruits.The TLC separation was achieved on cellulose pre-coated plates developed with concentrated hydrochloric acid-glacial acetic acid-water as mobile phase followed by densitometric measurements in visible. The HPLC separation was carried out on ODS-2 Hypersil column by gradient elution and detection at 520 nm. The mobile phase was a mixture of acetonitrile and phosphoric acid buffer in different ratios.Our methods have been successfully applied to find the fingerprint of anthocyanins and anthocyanidins of eight berry fruits which we used as reference materials at the analysis of fruit juices from market in order to establish their authenticity and conformity with the label inscription.