Part 52. Spices

Part 52. Spices are aromatic substances derived from hard or hardened parts of plants and used commonly in a pulverized state. For example, cloves (Fig. 122) are flower buds hardened by drying; allspice (Fig. 123), black pepper (Fig. 124), and red pepper (Figs. 125, 126) are dried berry-like fruits; mustard (Figs. 127, 128) is a seed; nutmeg (Fig. 129) is also a seed, and mace the fleshy network (dried) which surrounds it; cinnamon (Fig. 130) is the young bark of a tree; while ginger (Fig. 131) is a root-like stem which grows under ground.

The peculiar aroma of a spice is in general due to the presence of a volatile oil. Volatile oils bear a certain resemblance to the fixed oils, but differ from them in that they evaporate when exposed to the air, leave no greasy stain on paper, and all dissolve readily in cold alcohol. On account of the volatile nature of their flavoring constituent spices lose aroma when exposed to the air, especially after they have been ground.

Advantage is often taken of the ready evaporation of volatile oils to separate them by distillation. This process is essentially as follows. The material to be distilled-say some clove spice-is heated in a vessel tightly closed except that from the top comes off a long tube which passes finally through cold water. The volatile oil, after being driven off as vapor by the heat, is changed back to a liquid upon being chilled. Sometimes the substance to be distilled is mixed with water, and in that case the volatile oil passes off with the steam. Both are condensed together, and flow from the chilled tube as a mixture of oil and water. These two substances readily separate, however, since neither will dissolve the other more than slightly, and the oil will either sink (as oil of cloves and a few others) or float.

Most volatile oils form films of peculiar form and often beautiful color when a single drop is let fall upon a broad surface of perfectly clean water. The curious shapes assumed by the films are called cohesion figures.

The amount of volatile oil present in a spice is often exceedingly small, even when the aroma is strong. Ginger and black pepper have each about 1-2%; allspice 3-4.5%; nutmeg 2-8%. Cloves are remarkable in having 18% of volatile oil.

Oil of cloves is well known as a powerful drug, as is also the volatile oil of cinnamon. If taken in considerable quantities they act as poisons. The volatile oil of nutmeg is similarly poisonous if taken in more than small amounts. It is reported that the excessive use of this spice in India has resulted in dangerous, almost fatal consequences. In the small amounts necessary to give a mild and pleasant flavor to food all the spices in common use are not only wholesome to most persons but may be aids to digestion. Highly spiced food or strongly flavored confectionery, on the contrary, is apt to be unwholesome if much be eaten, and for young people positively injurious.

It is a curious fact that the volatile oil to which mixed mustard owes its aroma and pungency does not exist in the seed itself, but is formed, during the process of mixing, from a tasteless substance through the action of an enzyme. Like diastase this enzyme acts only in the presence of moisture, and is destroyed by a temperature of 100° C. Hence, if dry mustard be sifted into boiling water no pungency is developed.

Certain of the spices contain in addition to their volatile oil a considerable amount of fixed oil which may be readily expressed from them. Black mustard seeds contain 15-25% of fixed oil, white mustard 25-35%, and nutmeg 25-30%. In the manufacture of table mustard the fixed oil is commonly removed from the ground seeds by pressure. It resembles olive-oil, and is used in much the same ways.

While, as we have seen, the peculiar aroma of ginger and of black pepper is due to the volatile oils they contain, the hot biting taste of these spices depends to a considerable extent upon certain resinous substances which are present in small amount. A somewhat similar substance, of even greater power, causes the fiery taste of red pepper.

Spices have been of singular importance in the history of the world. In ancient times the spices of the East were among the most valued articles of commerce that were brought to the peoples about the Mediterranean. During the Middle Ages cloves, cinnamon, ginger, nutmeg, mace, and black pepper were considered to be as fitting presents for kings as gold and precious stones. Spices together with silk and jewels formed the principal merchandise of the caravans which at that time served as the chief means of communication between the nations of Asia and Europe. The great desire of European navigators to reach the Spice Islands of the East was the motive which led to many of the daring voyages of the 15th century, and impelled Columbus to brave the Western route that brought him unwittingly to the New World.

Fig. 122.-Clove (Jambosa Caryophyllus, Myrtle Family, Myrtaceoe). A, branch bearing leaves, flower buds, and expanded flowers. B, a flower bud (such as "form when dried the "cloves" of commerce) cut lengthwise to show the inner floral parts and the minute cavities near the surface containing the volatile "oil of cloves." C, petal showing oil cavities. D, stamen, a, front; b, back; c, side. E, pollen grain, a and b, different views, much magnified. E, fruit. G, seed cut across. H, embryo removed, side view. J, same with one seed-leaf removed, to show the seed-stem within. (Niedenzu.)-The plant is an exceptionally beautiful evergreen tree of pyramidal form 9-12 m. tall, with smooth grayish bark, thick glossy leaves containing numerous cavities like those of the flower, and filled with a similar fragrant oil which perfumes the air around; flowers and flower-buds rosy red, highly fragrant, produced through the year; fruit fleshy, grayish brown. Native home, Molucca Islands. In use from ancient times in the East.