Geographical differentiation of saffron according to amino acids and ammonium content
Amino acids play an important role in human nutrition and also affect the sensory traits of products . However, they have never been analyzed in saffron. Therefore, this study developed a method for extraction of amino acids and ammonium from saffron and they were derivatized using diethyl ethoxymethylenemalonate (DEFMM) and analyzed by HPLC . For optimization of the extraction method it was probed the time (15, 30, 60, 120 and 240 minutes) and extractive solvent (water, HCl 0.1 N, HCl 0.5 N and HCl 1 N). The best results for the amino acids and ammonium extraction were obtained using HCl 0.1 N during 60 minutes. Using this method, 20 saffron samples from different countries (Spain, Italy, Greece and Iran), 5 samples from each one, were analyzed. Alanine, proline, and aspartic acid were the majority amino acids in all the samples. Greek and Iranian saffron presented the highest amino acids content. The mean total content of amino acids and ammonium in saffron represented the 25% of the total nitrogen, which corresponds with the 2.02% of the dry mass of saffron . Furthermore, the amino acids profile allowed classifying the samples depending on the country.
References: 1. Belitz, H.D., Grosch, W. (1999) Food Chemistry. Springer. Berlin.
2. Gómez-Alonso, S. et al. (2007)J Agric Food Chem 55: 608–613.
3. Carmona M., Zalacaín A., Alonso G. L. (2006) El color, sabor y aroma del azafrán especia. Altabán. Albacete