ITDG 
Interdev Agroalimentaire  

Production of pectin

	Type de fiche	Techniques/Technologies
	Mise en œuvre	ITDG(Royaume Uni)
	
	Zone géographique	Global; 
	Mots clés	POMME; GRENADILLE; CONFITURE

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

Contexte
Pectin is a gelling agent used in jams and some sweets which is found to a greater or lesser extent in most fruits.  Pectin is extracted from citrus peel and apple pomace (the residue left after apple juice has been removed).  The amount of pectin varies with variety and with the maturity of the fruit.   Some other tropical fruits contain high levels of pectin, passion fruit being a notable example. The utilisation of the 'shells' remaining after pulp removal offers possibilities for pectin extraction. 

It is possible to produce pectin as a secondary product, utilising the waste products from other fruit processing operations.

Problématique / Objectifs
There are different types of pectin available - fast setting and slow setting types. The slow setting types are necessary for preserves that are left to cool and set in the jars.  Fast setting types are needed for larger containers or for preserves that contain suspended pieces of fruit or fruit peel. The concentration of pectin used for each varies from 0.2 to 0.7% depending upon the type of fruit being used. Pectin is usually supplied as 150 grade (or 150 SAG) which indicates the ratio of the weight of sugar to pectin needed to obtain a standard gel at 65% soluble solids.  

5 SAG is normally enough to produce a good gel, thus the 150 SAG pectin needs to be diluted 30 times to produce a 5 SAG strength.  Therefore, 3.3g 150 SAG pectin would be used for every 100g of sugar.

If commercial pectin is not available, it is possible to produce a pectin solution by boiling the sliced skins of passion fruit or citrus fruit in water for 20 to 30 minutes. The solution should be filtered before it is added to the fruit pulp. The amount needed depends on the type of fruit and the concentration of the pectin solution and can only be found by trial and error

Description/Mise en oeuvre
In essence the process of pectin extraction is not too complex.  The shredded fruit peel or de-juiced pulp is soaked in hot water (60-700C), or the hot water is re-circulated through the material, and the pectin is extracted into the water (along with sugars and other fruit components).  This is continued, often passing the same water through several batches of material, until the pectin concentration increases to around five per cent.
The pectin is then precipitated as a gel from the solution by adding one of a number of chemicals.  The most common are hexane or spirit alcohol which are then recovered by distillation and reused (the percentage of recovery and cost of this step are often the most critical in determining profitability).  It is also possible to use ammonium sulphate (a component of fertiliser) but this cannot be recovered and the higher cost therefore prevents its use commercially in large-scale operations.  The pectin gel is then washed and re-dissolved in water to produce a concentrated pectin solution.  It is at this stage that it is standardised or modified to give the specific properties required.  On a large-scale it is usually dried to a powder, but on a small-scale it is possible to add sodium benzoate preservative and sell the concentrated liquid in bottles.

Résultats/Eléments chiffrés
Pectin production requires a certain level of technical skill and knowledge of the process.

Enseignements
In most developing countries pectin is imported from Europe or USA and superficially at least there would seem to be a good market for supplying local fruit processors with pectin to substitute for imports.  However, there are major problems:

-  In countries where this has been tried, it has not been possible to produce pectin at a cost that is lower than the imported products.
-  It is difficult to produce pectin powder on a small-scale although liquid pectin is possible.
-  There is not one type of pectin but many types - each of which has specific properties that make it suitable for its intended application (eg jam that is to be used in baked goods requires a different type of pectin to normal jam sold in jars).

A detailed knowledge of pectin and its properties is needed to ensure that a producer is supplying the right product.While it is technically possible to produce pectin from fruit waste, there is no strong evidence to suggest that this is economically viable.  It is essential that full financial evaluation is carried out before attempting to produce pectin at the small-scale.

Production of pectin cannot be based on the availability of fruit wastes alone. It also requires the following: 
-  a good knowledge of the potential market for products and the quality standard required
-  a careful assessment of the economics of production
-  a certain amount of additional production knowledge
-  a certain amount of additional capital investment in equipment
-  a fairly large amount of waste to make utilisation worthw

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