References:

On Food and Cooking: 204-214; 560-574.

Plants and Society: 272-288.
 

What are herbs?
What are spices?
What is smell?
What is taste?
Why do we use herbs and spices?
Which plants are spices?
Which plants are herbs?

Essential oils contain organic molecules that react with receptor molecules cells in our tongue and nose and stimulate a response from our nervous system, either taste or smell.  Most essential oils are organic compounds called TERPENES, although there are other kinds of organic molecules that function as essential oils. In plants, essential oils in flowers may attract pollinators. In fruits and seeds, essential oils may be anti-herbivore defenses. In some cases, the essential oils produced by plants inhibit the growth of other plants, and thus act as a defense against competitors.

We sense taste with modified epithelial cells on our tongue. Epithelial cells line the surfaces of our respiratory and digestive systems, as well as the surface of blood vessels. The cells that sense "taste" are found on bumps on the tongue called PAPILLAE. Papillae may or may not have small clumps of cells called TASTE BUDS.  The sensory cells in taste buds have thin projections on their outer surface called MICROVILLI. Microvilli increase the surface area on the outer part of the sensory cell. The microvilli contain receptors molecules, molecules that react with specific molecules or specific classes of molecules. If a receptor molecule reacts with some molecule that comes into the mouth, The signal will be transmitted to the brain along nerve fibers attached to the sensory cells, and we will "taste" the molecule that comes into the mouth.

We sense smell with nerve cells. These specialized nerve cells. called OLFACTORY CELLS, have threadlike projections called CILIA on their upper surface. Cilia are complex cell structures usually used for locomotion. Secretory cells secrete mucous to keep the upper surfaces of the olfactory cells, including the cilia, moist. The receptor molecules of the olfactory cells are on the cilia, and they too react with specific molecules and classes of molecules that are dissolved in the mucous layer. Since the olfactory cell is itself a nerve cell, the reaction of a molecule from the environment with a receptor molecule on the olfactory cell stimulates a nerve impulse directly, and that impulse is transmitted to the brain, and we "smell" the molecule from the environment.

Spices and herbs are thus simply plants that contain molecules that react strongly (and in a pleasing manner!) with taste bud sensory cells and olfactory cells. Such plants have been sought after as a means of increasing the pleasure associated with eating. Spices are mentioned in The Bible as wealth in particular, and have been a major source of wealth. The use of spice and the development of a spice trade has required the development of a degree of civilization. Spices used in western Europe, for example, were derived from the traders in the middle east. Much of the wealth of the Roman Empire went towards the purchase of spice, particularly cinnamon and pepper. After the fall of the western Roman Empire, spices more or less disappeared from western Europe. Venice and the eastern Roman Empire (The Byzantine Empire) were the major sources of spice for Europe as it emerged from the dark ages. The Doge of Venice arranged for the destruction of the eastern Roman Empire by the crusaders, following which Muslim traders became the main competitors of the Venetians, eventually more or less destroying them.

One of the reasons western European nations began exploration of the earth was as a means of breaking the Muslim monopoly on the spice trade. Columbus was seeking a route to the spice producing regions of Asia when he "discovered" the new world. The major spice producing regions were dominated first by the Portugese, then by the Dutch, both of whom enslaved local residents in spice producing regions for the purposes of spice production. However, as others, most notably the British, began to cultivate spice producing plants in other regions, the importance of regions where spices were native declined. Spices are mass produced in many regions today, and while a certain amount of wealth is generated via the spice trade, it is nowhere near as great a source of wealth as it once was.

The Spices.

The spices are the plants that were highly sought after in the "old world", and were the major commodity sought after in western European explorations.

Cinnamomum zeylanicum is an evergreen tree in the Laurel family (Lauraceae) native to India and Sri Lanka.

Cinnamon is made from the bark of the tree.

Cassia.

Cinnamomum cassia is a small tree native to southeast Asia.

Cassia is made from the bark of the tree.

Cinnamon and cassia are very similar spices, and much of what we purchase in a store as cinnamon is actually cassia.

Black and white pepper are both derived from the dried fruit (berries), called peppercorns, of the climbing vine Piper nigrum, a species in the pepper family (Piperaceae), which is native to India and the East Indies. Black pepper is produced by picking the berries just before ripening. White pepper is produced by picking the berries after ripening. The berries contain more of the volatile oils before ripening, and thus black pepper is stronger than white pepper.

Cloves are native to the Spice Islands (Indonesia). Cloves are unopened flower buds picked from the small evergreen tree Eugenia caryophyllata, which is in the Myrtle family (Myrtaceae).

Nutmeg and mace are both derived from Myristica fragrans, a plant in the nutmeg family (Myristicaceae), which is native to the Spice Islands. Both nutmeg and mace are derived from the fruits of these trees. The fruit is a drupe, like a peach. This drupe, however, has a netlike fleshy red mesocarp surrounding the pit. This netlike mesocarp is called an ARIL. The aril is removed, dried and ground to produce mace. The pit consists of a stony endocarp and the seed. The pit is allowed to dry until the seed separates from the endocarp. The seed is then removed, and the seed is the nutmeg. Fake wooden nutmeg was produced and sold by Yankee traders in the 19th century, and the name Connecticut, the nutmeg state, is derived this scam.

Saffron is the world's most expensive spice. Saffron is derived from the stigmas of a Crocus species (in the Iris family, Iridaceae), Crocus sativus, the autumn crocus, which is native to the eastern mediterranean region. Since it takes so many flowers to produce saffron (100,000 flowers for 1 pound of saffron), many merchant will grind up petals of other plants and add it to the saffron. Saffron is derived from the Arabic word zafaran, which means yellow. Thus saffron can be mixed with ground up yellow petals to increase "yield".

Ginger (Zingiber officinale), Cardamon (Electtaria cardamomum) , and Tumeric (Curcuma longa) are species in the ginger family (Zingiberaceae). The species from which these spices are derived are herbaceous plants.

Ginger and tumeric spices are derived from the root of the plant, which can be sold fresh, or dried and ground. Cardamon seeds are used as a spice.

A variety of peppers in this plant genus (Capsicum) are used as spices. Capsicum peppers are derived from herbaceous plants in the Solanaceae, the nightshade family, that includes plants like tomatoes, tobacco and potatoes. Capsicum peppers are native to the new world.

We thing of these mainly a chili peppers, hot peppers, sweet peppers, and green peppers. Anyone familiar with the hot peppers, which are the spicy peppers, knows that the spicy chemicals, which are alkaloids, activate receptors in the mouth, eyes, skin, etc., that cause us to sense a burning sensation. Alkaloids are one of the more common defense compounds present in flowering plants. The alkaloid most prevalent in Capsicum peppers is CAPSAICIN. Capsaicin is found mainly in the seeds and placental regions of the fruit (the fruit is what we would call a pepper). Hot peppers are known to relieve pain, and it is thought that the active ingredients relieve pain by destroying nerve endings.

Vanilla, Vanilla planifolia, is a plant in the orchid family (Orchidaceae) native to the new world tropics. Vanilla is a vine that produces long pods from which the spice is derived. Pods are picked green, and must go through a long curing process during which the characteristic flavor of vanilla develops. The flavor of vanilla is due to a chemical called VANILLIN. When pods are properly cured, crystals of vanillin form on the surface of the pods. Vanillin is one of the spices that must be stored in an alcohol solution to remain active.

Fake vanilla, called imitation vanilla, is synthesized from a variety of compounds such as clove oil, lignin and coal tar. Fake vanilla does not have a real vanilla taste, and in some cases, such as when fake vanilla is made from extracts of tonka beans (Dipteryx odorata), the fake vanilla can be harmful, as tonka beans contain the chemical coumarin, a blood thinner that can cause internal hemorrhaging.

Allspice (Pimenta dioica) is another evergreen tree in the myrtle family, but allspice is native to the new world. The spice is derived from the berries, which are dried and ground. Allspice is named because its flavor is similar to that of a combination of cloves, nutmeg and cinnamon.. Unlike many other spices, allspice is difficult to cultivate outside of its native region.

Herbs are plants that are generally more common than spices, and thus are not considered as exotic. In modern cuisine's, however, most of our spices are herbs. We will look at 4 plant families that contain herbs (we have to be aware that botanically speaking, all green plants are herbs, but in the spice sense, herbs are spice plants where the essential oils are in green leafy tissues). Mints are characterized by having square stems and having glands on the outer surfaces of the plants that contain the essential oils.

Lamiaceae, or the mint family, contains many common herbs. Species in the genus Mentha, such as peppermint (Mentha spicata) or spearmint (Mentha piperita) are widely used as flavorings in a variety of products. We even use MENTHOL in cigarettes!

Other species of mint, such as those in the genus Origanum (Oregano) are used mainly in cooking and medicine. The two species in Origanum that we use, Marjoram (Origanum marjorana) and Oregano (Origanum vulgare) are most well known as the main flavorings of spaghetti and pizza sauce.

Another mint, Basil (Ocimum basilicum), gets it's name from the Greek "basileus", which means "king", and is called "the spice of kings". Basil is native to India, and is a sacred plant in the Hindu religion.

We mainly use basil to flavor tomato dishes.

Apiaceae, the parsley, or carrot family, are characterized by having an inflorescence called and UMBEL. In an umbel. all of the flower stalks radiate out from a single stem. forming an umbrella like inflorescence.
The most common spice in the Apiaceae is Parsley (Petroselenium crispum). Other spices in the Apiaceae include Celantro (Coriandrum sativum), Dill (Anethum graveolens), Caraway (Carum carvi, we use the seeds of this "herb" rather than the green parts as the spice), Celery (Apium graveolens), and Coriander (Coriandrum sativum) as well as many other spices.

The Brassicaeae, the mustard or cabbage family, includes many vegetables, like brussels sprouts, cabbage, turnips and radishes. It also includes a few spices, like Mustard (Brassica nigra or Brassica alba), where the essential oils are derived from the seeds. Brassica alba is the white mustard and Brassica nigra is the black mustard. The yellow color of prepared mustard is due to the presence of tumeric in the preparation. The tanginess of mustard comes from the interaction of the essential oils sinigrin in black mustard and sinalbin in white mustard. There are, of course, a number of mustard preparations, one major one being horseradish mustard.

Horseradish (Amoracia rusticana), contains the essential oils sinagrin and myrosin, which give it its biting taste. The essetial oils are concentrated in the root, and thus we prepare horseradish from the root of the plant.

Many of our most widely used herbs are in the lily family, including Garlic (Allium sativum), Onion, (Allium cepa), Leeks (Allium porrum), Shallots (Allium ascalonicum), and Chives (Allium schoenoprasum). These plants produce bulbs (such as the onion) or bulblets (such as in garlic), have long, thin leaves, and lily like flowers typical of monocots. The flavor and scent of Allium species is due to the presence of sulfurous volatile oils. The main volatile oil in onion is called the lacrimony factor, and the main volatile oil in garlic is allicin. These molecules can easily change into other compounds with a variety of biological effects. Changes are caused by enzyme activity (the enzyme allinase, for example).