Ground SpicesSpices may be milled to a wide range of particle size depending on their nature and ultimate use; the finer the powder the more readily available the flavor. In view of the many problems associated with purchasing, storing and handling spices, these are generally handled by specialist processor who have the necessary plant and skills to ensure that the raw materials are of the correct quality, that the grinding rate and the heat generated, as well as the methods of the handling and packing the ground material, result in minimum volatile loss or degradation.
Spices, once ground, are liable to serious loss of volatile constituents with a consequent weakening of their flavoring power. These materials should always be stored in cool, dry conditions and turned over regularly. If these simple precautions are ignored, the resulting seasoning may produce an unacceptable flavor level in the end product. In certain instances, a significant degradation of flavor quality may also occur during storage. This may due to oxidation oil constituents or of any fixed oil present, or, in certain instances; it may be the result of enzymatic changes. One has only smell a sample 
of ground pepper as purchased from a supermarket against that of a freshly-ground sample from a hand pepper mill to appreciate the great difference in aromatic quality between the two. The pungency of the pepper will not have change but the odor most certainly has. With umbelliferous fruit (e.g. caraway, cumin, etc) the onset of rancidity is the main cause of off-odor notes. In the case of ground paprika, this may also be accompanied by a fall-off in tinctorial power.Ground Spices
