ITDG 
Interdev Agroalimentaire  

Small-scale production of lime pickle

	Type de fiche	Techniques/Technologies
	Mise en œuvre	ITDG(Royaume Uni)
	
	Zone géographique	Global; 
	Mots clés	MANGUE; PICKLES; FERMENTATION

	Echelle d’action	Groupe; Famille/Exploitation familiale
	Public(s) cible(s)	Small- and medium-scale food processors

Contexte
Lime pickle is made from salted pieces of lime (Citrus aurantifolia) that is packed in a salty, spicy liquor, rather like a semi-solid gravy.  It is brownish red in colour and the lime peels are yellow or pale green with a sour and salty taste.

Lime pickle is eaten as a condiment with curries or other main meals.  If it is processed well, the product can keep for several months.

Other fermented products, including mango pickle, pickled cabbage (kimchi and saurkraut) and pickled cucumbers, can be made by a similar salting method.

Problématique / Objectifs
The limes are preserved by a combination of salt, increased acidity and lower moisture content, which inhibit the growth of many spoilage micro-organisms.

The addition of salt to the limes draws some water out of the limes by osmosis.  This process also removes some of the sugar present in the fruits.  The salty environment encourages the growth of bacteria that are salt-tolerant and which can ferment the limes. These are mainly the lactic acid producing bacteria.  When they ferment the limes, they produce lactic acid, which increases the acidity of the product, which contributes to the taste of the product and extends its shelf life.

Packaging prevents contamination of the pickle by dirts and moulds.

As with all food products, it is essential that proper hygienic procedures are followed.  It is important that the lactic acid bacteria proliferate and not the pathogenic bacteria, which will cause spoilage and be a potential source of food poisoning.  Adjusting the salt content to the desired level is crucial in controlling the type of bacterial growth. 

Description/Mise en oeuvre
A detailed production flow sheet is available (ref link).

The basic process is as follows:
  selection and preparation of raw material
  mix with salt
  dry
  addition of spices
  package
  fermentation
  repackaging
  storage

Selection and preparation of raw material
Only fully ripe, good quality limes should be used.  They should have dark yellow skins, without any infection or mould growth.  The skins are not removed in pickle making.  Over-ripe limes should not be used as they will have a poor flavour and the fermentation may not be successful.
Since the skins are not removed, the limes should be washed well in clean water, then dipped in hot water (60-65 C) for about 5 minutes.  This helps to soften the skin and make it easier to ferment.  The limes are then cut into four pieces (or may be cut into smaller uniform sized pieces). Cutting the limes exposes the interior and allows the salt to be absorbed more rapidly.

Mix with salt
The cut limes are dipped in a saturated salt solution for 20-30 minutes.  Alternatively, the cut lime pieces are packed in layers with the salt (1kg salt per 5kg limes). This causes the juice to run out of the limes. It is essential to make sure that the surface is covered in juice. The limes are left in the salt for up to 24 hours. If necessary, they may have to be held down under the brine, as the pieces start to rise to the surface after some time.

Dry
The salted limes are dried in the sun for 2-3 days or until the skin becomes brown and the pieces are soft and breakable.  Sometimes salt crystals are sprinkled on the lime while drying.

Addition of spices
The fenugreek seeds are dry roasted until they begin to 'splutter'.  All the seeds are finely ground to a powder and added to the fruit.

Package
The pickle mixture is packaged into clean, sterile glass jars and sealed.

Fermentation
The jars of pickle are stored in a cool place away from direct sunlight to allow fermentation to take place.  This takes about one month.

Repackaging
After fermenting, the pickle is re-packed in pre-sterilised jars or plastic bags, ensuring that there are no air bubbles trapped in the pickle.  A layer of vegetable oil is added to the top of the pickle to act as a seal, to keep out air and moisture.

Storage
The pickles are stored, in a cool place away from direct sunlight.  If they are properly processed, the pickle scan be stored for several months.  Although the pickles are salty and acidic and therefore not at serious risk from food poisoning, strict hygiene should be enforced since the pickles are not cooked before consumption.

Résultats/Eléments chiffrés
The following ingredients are used for one batch of pickle:
5kg limes
1kg salt
5g turmeric powder
150g chilli powder
100g fenugreek seeds
100g mustard seeds

The fruit should be fully mature and of good quality, without bruising or damage. The spices should be good quality and free of mould or adulteration.

The following equipment is required:
Scales
Heat sealer or jar capper
Filler
Stainless steel mixing pan

Enseignements
Fermentation takes place during the one month that the pickle is in storage. It is during this time that the lactic acid is produced and the distinctive flavours, texture and colour of the pickle are developed.  During fermentation, the jars should be kept in a cool place, away from direct sunlight.

In terms of food safety, salted lime pickle is a fairly safe product because of the level of salt and acid and the low levels of water in the product.  However, even though it is safe, strict attention should be paid to personal hygiene to prevent contamination of the product. 

Lime pickle is a good product for small-scale production.  However, as with all food products, the processor should carry out a market survey to determine the local demand before going into production.

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