Herbs and SpicesHerbs and spices are what make our food enjoyable. They are essentially all plant products, and mostly all get their flavor from plant secondary chemicals. Spices come mostly from tropical regions, herbs are more from temperate areas. The herbs’ flavor generally comes from aromatic leaves. The aroma comes from volatile oils.

Further, many are essential oils built from a basic unit that is a terpene:

A diterpene phosphate, the carbon backbone is C10H16

The basic unit for these terpenes is C5H8 , but multiples of this unit are what we find as the essential oils.

Wikipedia lists more than 30 herbs used in cooking of various international cuisines. We can’t begin to consider all of them. Among the more important ones are:

From the mint family (Lamiaceae): peppermint, spearmint, marjoram, oregano, rosemary, thyme, sage, savory and basil

peppermint oregano sweet basil

From the parsley family (Apiaceae): parsley, dill, caraway

From the mustard family (Brassicaceae): mustard, horseradish (in the mustards the flavour is released by a reaction between an enzyme, myrosin, and sinigrin (in stronger black mustards) or sinalbin (in milder white mustards).

parsleycaraway

The reaction releases volatile essential oils. Preparation with acid (vinegar) causes the reaction (and the flavour) to last much longer.

mustard

wasabi

horseradish

From the lily family (Liliaceae): onion, garlic, leek, shallot, and chives (all contain closely related sulphurous compounds; the one in garlic is called allicin since onions, garlic, etc. are all in the genus Allium. All these species seem to originate in central Asia. The individual species are:Onions – Allium cepaGarlic – A. sativumLeeks – A. porrumShallots – A. ascalonicumChives – A. schoenoprasum

garlic in flower

If you need an excuse to eat onions and garlic, here’s what allicin is believed to do:

1. inhibits pathogenic bacteria by blocking enzymes they use to penetrate healthy cells2. inhibits the formation of blood clots (that should lower the probability of heart attacks and strokes)3. inhibits cholesterol synthesis (lowering LDL and probably triglycerides in circulation)

The only problem with consumption of onions, garlic, etc. is that the sulfurous compounds directly consumed and modified into others enzymatically enter the circulation from the digestive tract, are circulated to the lungs, and diffuse into the gases of the lungs. When you exhale, you smell of the sulfur compounds.

Many herbs were used for centuries as natural dyes. Some are also used as spices (note the sneaky transition). Among them:

Tumeric (or turmeric; Curcuma longa, in the same family as ginger) – a bright yellow rhizome. The active ingredient as a spice is curcumin. It is actually not a very good dye for cloth, because it fades readily in light.

However, it is a widely used food dye. It is the reason mustard and Indian curry powder are yellow.It also has uses in medicine: It inhibits the plaques that characterize Alzheimer’s, it helps with STDs chlamydia and gonorrhea, and has been suggested as an anti-cancer drug.

Indigo was an herbal dye obtained from Indigofera tinctoria. Aztecs used indigo to dye cloth, and its use continued into the 20th century before replacement by a synthetic dye.

It’s indigo dye that colours our bluejeans. The Celts went into battle having stained their faces and bodies using a temperate plant (Isatis tinctoria) that has the same chemical (indigotin) in the leaves. Think of Mel Gibson playing William Wallace in Braveheart.

There are closely related species, with flowers that are ‘electric’ blue in midwestern prairies.

Herbal blue dyes were rare; so were herbal red dyes. The one that was used for centuries was the madder plant (Rubia tinctorum). This is the plant the British army used to dye the red coats they were famous for at the time of the American Revolution. The plant is in the same family as coffee (remember those red fruits?)

Another red dye plant, of great importance in science, was a bean known to the Aztecs for its dye quality, and later used as a stain in cellular microscopy, Haematoxylium spp.

The dye system used in microscopy combined hematoxylin (red) with eosin (blue) that stained different parts of tissues and cells. Hematoxylin has not been replaced with a synthetic dye.

This is a picture of lung tissue from someone with emphysema

Table 17B in the text lists a number of other plants used as dyes and the colours they produce. Among the more common:Black walnut (Juglans nigra) – the pulp surrounding the walnut is used as a dark brown dye.

Various Coreopsis species’ flower heads (basically petals) are used to produce an orange dye.

The outer, dry layers of yellow onion (Allium cepa) were used to make a dye to colour cloth burnt orange.

Lastly, what seems like an unlikely colour from the colour of the plant tissue extracted: a blue or lavender dye extracted from the outer leaves of red cabbage (Brassica oleracea).

Spices

Definition (Oxford English Dictionary) One or other of various strongly flavored or aromatic substances of vegetable origin, obtained from tropical plants, commonly used as condiments.

Spices are typically of tropical origin. They are aromatic plants parts – leaves, twigs, bark, flowers or other plant parts.

The search for spices was one of the driving forces in world exploration. Going back to the heyday of the Egyptian pharaohs, herbs and spices were in common use. There was, even then, an established spice trade between the Mid-East and Southeast Asia and China.

Arab traders were the agents by the time of the Golden Age of Greece. Alexander the Great built Alexandria as the key trade center between Asia and Europe, and the key product in this trade was spices.

Marco Polo traveled throughout much of China, but also visited (and later wrote about) Java and India. The spices he described included pepper, cinnamon and ginger.

Overland trade was slow, inefficient, and subject to seizure along the route. The exploration of navigators like Vasco de Gama, Christopher Columbus and others was a search for a sea route from Europe to Southeast Asia, China and India.

It was Ferdinand Magellan who discovered a route to the Spice Islands, where cloves, nutmeg and mace were native, in the course of his round-the-world voyage.

Much more recently, a voyage by Alfred Russell Wallace was duplicated to show English schoolchildren the Spice Islands. Apparently it is a tricky and dangerous sailing trip, and Wallace’s accounts tell much about his travails.

Originally, most spices came from the Old World. More recently a number of New World spices have been added to our gustatory spectrum.

Old World spices:

Cinnamon – there are two plant sources, one more properly called cassia (Cinnamomum cassia) from southeast Asia, and the other the higher quality cinnamon (Cinnamomum zeylandicum or aromatica) native to India and Sri Lanka.

The spice we use is the inner bark of the tree for cinnamon or the whole bark for cassia. That inner bark curls as it dries and forms what we call cinnamon sticks. Broken pieces are ground into cinnamon powder.

Pepper – here we need to be careful, there are two very different kinds of plants described as peppers. The black and white pepper you grind comes from Piper nigrum, and are the dried berries of a climbing vine native to India and the East Indies.

Black pepper comes from picking these green berries and allowing them to dry, blacken and shrivel.

White pepper comes from allowing the berries to ripen on the vine, then removing the hull, leaving the whitish seed kernel within.

New World peppers are completely separate. They are in the genus Capsicum, of which there are 5 major species, but probably thousands of varieties. All are in the same family (Solanaceae) as tomatoes, eggplants, and tobacco. To separate them, sometimes New World peppers are called chili peppers. They have been in cultivation in the Americas for at least 9,000 years.

“Heat” among these peppers is measured on a scale called Scoville units. It comes from alkaloids primarily in the ribs that seeds are attached to within the pepper and the seeds themselves. The most important is capsaicin. Capsaicin is the active ingredient in pepper spray. Heat is not necessarily evident from what species a capsicum pepper is in. For example, both ordinary bell peppers and cayenne peppers are varieties of Capsicum annuum (Scoville units <1 to ~40,000).

The hottest peppers are the habanero or Scotch bonnet peppers (Capsicum baccatum) with a Scoville rating of 100,000 – 300,000. All these peppers originate in southern Mexico and Central America.

Scoville units: 100,000 – 350,000

Thai peppers: 50,000 – 100,000

Jalapenos: 2,500 - 8000 Green pepper: 0

As a comparison, police pepper spray has a Scoville rating of 500,000 – 5,300,000.Other old world spices:Cloves – the unopened flower buds of Eugenia aromaticum

Nutmeg and Mace - from Myristica fragrans native to the Spice Islands. The species is dioecious (separate male and female plants). Mace comes from a netlike aril within the fruit. The dried seed within is nutmeg.

Saffron – comes from the stigmas of the flowers of the autumn crocus, Crocus sativus. It is native to the eastern Mediterranean and southwest Asia (sometimes called Asia Minor). You can grow it locally! However, it takes 800,000 stigmas to make up one kilogram, and there are only 3 per flower. It was used as a yellow dye, and is still used in cooking both for flavor and to give a yellow colour, for example in the rice of Spanish paella.

Lastly, vanilla. It comes from the ‘fruit’ pods of the vanilla orchid, Vanilla planifolia. This is a tropical, perennial vining orchid originally from southern Mexico and Central America. Today, the largest producer is Madagascar.

vanillin

To maximize fruit production, flowers are hand-pollinated. The pods are picked green and allowed to ferment for weeks to several months, alternately heating and cooling them. During this process they blacken. During the curing there is a chemical change, and the pods produce vanilla as crystals on the pods. The extraction process percolates 35% alcohol over the cured pods, which extracts both the vanillin and other chemicals that contribute to the flavor.

Imitation vanilla is now produced (synthesized) from clove oil, lignin, or coal tar. Now you know why the real stuff tastes better.