Chemistry - Particular odors and smells are due to compounds known as essential oils, usually from class of hydrocarbon compounds known as terpenes but can also be aldehydes, esters, ketones, alcohols and phenol-based compounds.

Ecology - Volatile compounds used to attract pollinators and repel herbivores. Some compounds are washed into soil and prevent the growth of other plants via inhibition of germination and poisoning of competitors (allelopathy).

Herbs and Spices

Not a clear distinction between herbs and spices, botanically, a herb is a nonwoody plant but herbs have a more specialized meaning in the horticultural industry. Spices can come from all types of plants and parts of plants, herbs generally refer to leaf material (herbage). Some herbs are spices but not all spices come from herbs.

Spices were at one time extremely valuable, were used to help in food preservation, make spoiled palatable, flavoring, embalming.

Romans used spices in wine, lamp oils, perfumes, incense and food. Mohammed, founder of Islam, was a spice trader in his youth.

Europe had no source of spices, with few exceptions, during Dark Ages 641-1096. Crusades opened up spice trade, Venice and Genoa became centers of trade between Europe and Near and Far East. Columbus was from Genoa and was looking for a route to the East when he discovered America. Vasco de Gama reached India by sailing around Africa, Portugal dominated spice trade initially, then Dutch controlled it for 200 years and was supplanted by the British which developed the largest navy in the world.


Plants of the Mediterranean Region

Many of the plants that are referred to as herbs are members of the Lamiaceae - Mint family and are the dominant species along the Mediterranean sea coast. These plants have fragrant leaves; the compounds that are responsible for the fragrances probably serve as feeding deterrents.

Rosemary - Rosmarinus officinalis - tea, perfume, cooking

Thyme - Thymus vulgaris - mouth washes, cough drops (Thymol), cooking

Oregano - Origanum vulgare - Italian food

Marjoram - Origanum majorana - milder flavor than oregano

Basil - Ocimum basilicum - basil - pasta sauces

Sage - Salvia officinalis - Used medicinally by Greeks through Middle Ages but modern testing indicates sage has no medicinal properties. Used to flavor poultry and other meats, especially sausage.

Spearmint - Mentha spicata

Peppermint - Mentha peperita - most frequently used mint - jelly, candy, medicines, obnoxious gum commercials, etc.

The Apiaceae - carrot family are second to the Lamiaceae in terms of the number of taxa which are used as spices and herbs.

Herbage

Parsley - Petroselinum crispum - garnish

Chervil - Anthriscus cerefolium

Dill - Anethum graveolens - pickling

Cilantro - Coriandrum sativum - Mexican, Indian dishes

Dried fruits (Spices) - fruit is composed of pericarp and seed, oils are in fruit wall

Fennel - Foeniculum vulgare - Italian sausage

Cumin - Cuminum cyminum - Indian and Mexican foods

Anise - Pimpinella anisum - Licorice flavor

Celery seed - Apium sativum

Caraway seed - Carum carvi -rye breads, sauerkraut


Brassicaceae

Black mustard - Brassica nigra - native to Europe

White mustard - Brassica alba

Horseradish- Armoracia rusticana - grated roots

Odds and ends

Tarragon - Artemisia dracunculus - used in vinegar in S. Russia

Bay leaves - Laurus nobilis - from Meditteranean

Saffron - Crocus sativus - Iridaceae (Iris family), most costly spice, comes from stigmas, requires 150,000 flowers/kg

Spices from Old World Tropics

"True" cinnamon - Cinnamomum zeylandica

"Common" cinnamon - Cinnamomum cassia
Both cinnamons are from SE Asia and are obtained from the bark

Cloves - Syzygium aromaticum - from Spice Islands or Indonesia, harvested as immature flower buds, used in Indonesian cigars, clove oil, but oil can be synthetically produced.

Nutmet and mace - Myristica fragrans - nutmeg is the dried endosperm of seed, not a true nut, toxic in large quantities, put on egg nog; mace is netlike aril around seed

Cardamon - Elettaria cardamomum - oils originally used in medicine, now used in Indian cooking and Danish pastry

Ginger - Zingiber officinale - rhizome

Pepper - Piper nigrum - drupes, most important spice in terms of quantities, can make raw drupes into black or white pepper depending on processing

New World Spices

Allspice - Pimenta dioica - mostly grown in Jamaica, combination of flavors of cinnamon, cloves and netmeg

Bell peppers, chiltecpin (tiny and hot) - Capsicum annuum - paprika is made from dried, powdered members of this species

Other pungent peppers - Capsicum fructescens - tabasco sauce
Compound responsible for hot flavor is capsaicin, which is contained in the placenta

Vanilla - Vanilla planifolia - only crop from Orchidaceae - over 20,000 species in this family, fruit is called a bean but is a false berry from an inferior ovary, vanilla is the 2nd most expensive spice due to laborious cultivation and processing requirements, vanilla can be made synthetically but taste is inferior to natural vanilla

PERFUMES
Used for at least 5000 years. Egyptians, Hebrews, Chinese, Japanese, Greeks, Romans all used perfumes but Europeans did not use them until the Crusades. French are current leaders in perfume production but U.S. companies are strong challengers.

Perfumes were originally extracted from plants and animals and placed in a base which could be applied to the skin. Many of the compounds used in perfumery are hydrophobic and must be extracted with organic solvents, then fixatives are added to prevent loss of volatile compounds.

The basic ingredients are odorants:
1. concretes - first extraction with hydrocarbon solvent
2. absolutes - produced by extracting concrete with alcohol; waxes and glycerides are left behind, alcohol is evaporated, most perfumes are mixtures of absolutes.
3. distilled and fractionally distilled oils - involves steam extraction and fractionation. Oils are skimmed off condensed water, is inexpensive and rapid but destroys some fragrances.
4. expressing oils - oils are pressed out of tissue - citrus rinds
5. tinctures - substances are heated in alcohol, used mainly for animal substances

Many compounds used in perfumes are synthesized

Blending of fragrances is an art and producing a new scent can cost $2-$3 million, mostly for advertising.

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