Saffron Laboratory Report
The compounds which are important in saffron are crocin (responsible for color), picrocrocin (source of flavor) and safranal (the aroma of the spice). The higher the amounts of these compounds the higher quality the saffron at hand will be. The ISO (International Organization for Standardization) has set a classification of saffron based on minimum requirements for each quality (color, flavor and aroma). According to the ISO, picrocrocin, safranal and crocin are expressed as a direct reading of the absorbance of 1% aqueous solution of dried saffron at 257, 330 and 440 nm of light, respectively.
With each saffron importation we demand a laboratory report for that particular shipment.
The most relevant information obtained from laboratory tests in relation to the purchase of saffron are:
- Moisture and Volatile Matter: The maximum percentage allowed is 12%. This is one of the most important characteristics for saffron, and the one that is most abused by packers and exporters, in relation to the coloring strength which is an overall indication for the quality of saffron.
- When the yellow part of the saffron stigma is left attached to the red part, moisture is trapped and the saffron becomes musty. This is why many writers describe the aroma of saffron as “musty”, a smell which is not the true aroma of saffron. You get aroma when you cut out the yellow: when no moisture remains.
- If the yellow, which has no culinary value, is left attached it increases the weight of the saffron by at least 25%, plus another 6% from the trapped moisture.
- Moisture decreases the flavor, the aroma and the shelf-life.
- The yellow part must be removed before saffron is dried. Sargol, in Farsi, means the “top of the flower”, “Coupé” in Spanish; the top detached from the yellow parts. Properly dried and cured saffron, like the all-red Sargol or Pushal, is brittle to the touch and can be crush between the fingers.
- Extraneous Matter: The maximum allowed for Category I is 0.1%.
- Picrocrocin: The flavor of the spice is attributed to the compound picrocrocin. For Category I the minimum value is 80.
- Safranal: Safranal gives saffron its aroma.
- Crocin: Saffron color derives from crocin. This is the most important value because a high degree of coloring strength can only be obtained by cutting out the yellow, thus making the saffron all-red. There is a general idea that the higher the coloring strength, the better the saffron.