Spice flavours information

Important flavour compounds found in culinary herbs and other spice plants are:

• eugenol (allspice, cinnamon, cassia, clove)
• piperine (black pepper)
• gingerol (ginger)
• myristicin (nutmeg)
• turmerone (turmeric)
• vanillin (vanilla)

The main flavour compounds found in the major herbs and spices used by the food industry are summarised in the tables below. In using spices to flavour foods, the aim should always be to arrive at a balanced overall odour and flavour effect, complementing and accentuating, rather than swamping, the flavour of the basic ingredients, and usually without any single spice predominating excessively. This culinary art needs experience and expertise and in–house training with the assistance of leading spice houses.

Spices can be added to foods in several forms: as whole spices, as ground spices, as essential oils, as oleoresins or as prepared and filtered vinegar infusions. A more recent alternative is spice extracts. These consist of the flavour components of a spice, dispersed on one of several types of base, the most suitable bases for pickle and sauce use, for example, being salt or dextrose. Natural materials used in flavour creations are still most often isolated from essential oils. Extraction of oils and oleoresins is accomplished using a range of methods including:

• steam distillation
• hydrocarbon extraction
• chlorinated solvent extraction
• enzymatic treatment and fermentation
• super critical carbon dioxide extraction

Carbon dioxide extraction from solid botanicals is now on a commercial scale. The advantages of the resulting essential oils are no solvent residue, less terpenes and enhanced black notes. Enzymatic treatment and fermentation of raw botanicals also result in greater yields and quality of essential oil. More recently, the use of genetic engineering and recombinant DNA on the bacteria and fungi used in fermentation has resulted in natural esters, ketones and other flavouring materials "made to order". Cloning and single cell culture techniques are of benefit to the flavourist, for example in cultivating flavour cells from black pepper, cardamom or thyme instead of growing the entire plant. In vitro synthesis of secondary metabolites may, in the future, lower market prices of traditionally–cultivated spices.

There have also been improvements in preservation technologies to ensure that raw spices in particular are free of microbial and other contamination and that their shelf–life is extended. Techniques include osmotic dehyration and storage within a medium such as high fructose corn syrup. With the banning of chemical treatments such as ethylene oxide in treating microbial contamination, irradiation has grown in popularity, with an estimated 25,000 tonnes of raw spices currently irradiated each year to counter both insect and microbial contamination. Countries with commercial–scale irradiation operations for herbs and spices include: the USA, Canada, The Netherlands, Belgium, France, Denmark, Finland, Israel, Iran, the Republic of Korea, Vietnam, South Africa and a number of Eastern European countries.