Determination of colour and aroma components in different qualties of Iranian saffron

Saffron which is the most expensive spice nowadays, has been used in different industries such as food, drug, cosmetic and paint industries from past to present and never lost the economic importance of trade in the world today. Due to saffron is an expensive spice, adulterations and tricks are applied as it used to be in the past and still today. However, despite the fact that there are no adulterations and tricks, there are different qualities of saffron and different prices depending on the qualities. For this reason, a standard published by the I.S.O. (International Standard Organization) classifies Saffron into 4 groups depending on the quality. In this thesis, Iranian saffron samples, sold under 5 different classes (All Red, PS, PI, PII and Bunch) in Iran, which ranks first in production and export of saffron, were categorized according to ISO standarts. The quality characteristics of saffron were determined by physical ( L, a, b colour, moisture), chemical (total phenolics and flavonoids content, antioxidant activity) and chromotographic ( colour, flavor and aroma compositions) analyses., saffron samples According to these results, total phenolics, total flavonoids contents and antioxidant activity of the saffron samples values varies between 14.07?34.04 mg GAE/g DM; 3.16-33.64 mg/g DM; 20.52-52.83 ?mol/g DM respectively and changed significantly (p?0.01) depending on the classification and extraction solvent. L, a, b analysis were performed on ground saffron samples, and the extracts obtained from these samples. L, a, b values of the ground saffron samples changed between 51.99-54.02; 18.69-22.76 14.00-19.67, respectively. In addition, of the extracts L, a, and b values varied between 37.00-37.67; 1.80-15.30 and 7.50-8.74 respectively. HPLC results showed that, the highest total crosin content was determined in All Red sample (37.37 mg/g) and the lowest total crosin content was in Bunch sample (33.05 mg/g). The results also showed that, picrocrosin content which is as a precursor of the bitterness, decreased significantly (p< 0.01) from All Red sample (5.21mg/g) to Bunch sample (4.11mg/g) according to the classification. Saffron volatile components were determined by SPME method in GC-MS. According to the relative quantification values (%) important aroma components were determined as safranal, 3,5,5-Trimethyl-2-cyclohexenone-1-one, 2,6,6-Trimethyl-2-cyclohexene-1,4-dione, acetic acid, limonen-10-ol, 2-(5H)-Furanone, eucarvone, ?-isophoron and 3,5,5-Trimethyl-1,4-cyclohexadione) in all saffron samples. Safranal which is the most important aroma component of saffron was determined the highest level in Bunch sample.