Annex White book.pdf

A4.1.2.9 UV-Vis SpectrophotometryThis method enables the determination of the main features of saffronregarding picrocrocine, safranol and crocine content. Greek andSpanish producers and enterprises use the method described in section14 of the technical specification ISO/TS 3632-2:2003. The Spanishgovernment (inspection authority SOIVRE) uses the SOIVRE methodto determine the coloring ability of saffron destined for export to nonEuropean Community countries.Technical Specification ISO / TS 3632-2:2003, section 14The following procedure is applied: 500 mg of saffron are weighed ina precision scale (variation ± 1 mg). The sample is placed in a 1000 mlvolumetric bottle and 900 ml of distilled water are added. The solutionis agitated with a magnetic agitator (1000 rounds / minute) for an hourwhile it is protected from light exposure. Water up to 1000 ml is thenadded and the solution is homogenized through agitation. 20 ml of thesolution are decanted to a 200 ml volumetric bottle and water is added.The solution is homogenized through agitation. The solution is filteredthrough water absorbent polytetrafluoroethylene filter (PTFE) with a 0,45mm pore diameter. The solution is placed in quartz tube and a transmissionoptical density between 200 and 700 nm is measured usingwater as reference fluid. The ISO shows an example of a characteristicspectrum for this solution measured between the above two wavelengths(picture 1). Alterations to this spectrum reveal the existence of adulterationusing significant amounts of exogenous dye material.152