ITDG 
Interdev Agroalimentaire  

Small-scale processing of cloves (Eugenia aromatica)

	Type de fiche	Techniques/Technologies
	Mise en œuvre	ITDG(Royaume Uni)
	
	Zone géographique	Global; 
	Mots clés	EPICE; GIROFLE; SECHAGE

	Echelle d’action	Groupe
	Public(s) cible(s)	Small- and medium-scale food processors

Contexte
Cloves are the dried flower buds of the plant Eugenia aromatica. They are golden brown to black in colour, about 1.7-2.5cm in length, rubbery or crisp to the bite and with a strong characteristic taste on the tongue and a strong aroma.  They are used as a flavouring in many traditional dishes. The oil of cloves has a strong aroma and flavour and has medicinal and antiseptic properties. It is used in the flavourings and perfumery industries.

The clove buds are preserved by drying. The low moisture content prevents the growth of micro-organisms.  When the spice is carefully dried and packed in moisture- and air-proof containers, it has a shelf life of more than a year.

Problématique / Objectifs
  The buds should be detached from the stem by taking a cluster in one hand and pressing this cluster against the palm of the other hand and twisting. The buds will then drop off. The buds and the stems should be separated by hand and dried separately.
  The buds and stems should be dried as soon as possible or they will start fermenting.  If they start to ferment, the final colour is pale and dull.
  Drying is very important and must be carried out quickly under controlled conditions to avoid mould growth and loss of flavour. 
  The final moisture content of the product is important. Drying must continue until the final moisture content is below 12%. This may be achieved in 3-5 days with about 8 hours sun drying per day.  In rainy conditions, this will take longer, which can result in an inferior quality dried product.
  An experienced processor will know when the cloves are dry enough. As a quick test, the dried clove can be bent over a thumbnail. When it is dry enough, the clove snaps; if it bends, it is not dry enough. Also, when a handful of dry cloves are picked up and grasped, it hurts.  If the cloves do not hurt the inside of the hand, they are too soft and need further drying.

Description/Mise en oeuvre
The processing of cloves follows these basic steps:

  Harvest
  Sorting
  Drying
  Winnowing
  Packaging and storage

A process flow sheet is available (ref link)
Harvest
The flower buds are picked when they are a greenish yellow colour. Immature green buds should not be collected as they contain less essential flavour. They should be left on the bush to mature and processed later. Some buds fall off the inflorescence and can be picked off the ground and washed if they are not damaged or rotten.
The buds are detached from the stem by twisting the cluster of buds against the palm of the hand.

Sorting
The stems are removed from the buds and leaves and other unwanted material is removed from the buds and discarded.

Drying
The buds are placed on mats or woven containers in the shade for several days until they reach a final moisture content of 12%. Direct sunlight should be avoided as this can cause undesirable breakdown of the flavour components.  

Winnowing
Dust, dirt and other foreign matter is removed by winnowing the dried seed.

Packaging and storage
The dried cloves are packaged in polypropylene as this protects the product from air and moisture.  Polythene is not suitable as it allows the volatile components to pass through. The packets should be stored in a cool, dry place, where they can be kept for up a year or more.

Résultats/Eléments chiffrés
The following equipment is required:

Mats for drying or drier
Winnower 
Packaging material
Heat sealer
Weighing scale

Enseignements
  Processors should pay strict attention to hygiene.  During drying (if sun-dried) the cloves should be protected from dust and dirt. Animals, rodents and birds should be kept away from the cloves during drying as they are a potential source of contamination. 
  During the rainy season, or to speed up the drying process, cloves can be dried in a mechanical drier.  The choice of drier will depend on local availability, price and scale of operation. 
  With proper processing, packaging and storage, dried cloves can be stored for over one year.  However, after some time the flavour components begin to decrease.

Auteur : Sue Azam Ali
Saisie le : 06/12/2001
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