ITDG 
Interdev Agroalimentaire  

Production of mixed fruit juice

	Type de fiche	Techniques/Technologies
	Mise en œuvre	ITDG(Royaume Uni)
	
	Zone géographique	Global; 
	Mots clés	JUS; PASTEURISATION; FILTRE; FRUIT; GRENADILLE; PULPE; ANANAS

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

Contexte
Passion fruit produces a juice with a very strong exotic flavour and a bright orange colour.  Pineapple produces a juice with a weaker flavour and colour.  The two complement each other very well and can be mixed to produce a very pleasant tasting juice. 

Fruit juices rely on a combination of acidity, pasteurisation and packaging in sealed containers for their preservation. They have to be drunk immediately after opening. If care is taken over the packaging, pasteurised juices can be stored in a cool dark place for up to a year.  It is normal for some sediment to form at the bottom of the bottle as it is left to stand, but if this is excessive, a finer filter can be used.

Problématique / Objectifs
Passion fruit juice is unusual in that it has to be made from fruits that have ripened and dropped to the ground.  If fruits are picked from the tree they will not have reached the correct stage of maturity and will lack the pleasant flavour associated with the fruit.  Care must be taken to ensure that old fruits that have been lying on the ground for several days are not used as these will have rotted and will spoil the flavour and quality of the juice.

Passion fruit juice has a pH of 2.6-3.0 and an unusually high starch content.  The yield of juice from passion fruit is approximately 30-35%.  The bigger fruits (more than 30g) are more suitable for processing as they have more juice and less rind.  There are two important commercial varieties - purple passion fruit (Passiflora edulis) and yellow passion fruit (Passiflora edulis forma flavicarpa).  The latter has larger fruits, a more acidic juice and a less preferred flavour.

Pineapple juice has a pH of 3.4-4.1 and gives a juice yield of about 30%.  The Mauritius variety has the best flavoured juice, but the Kewpine variety gives better yields.  Pineapple contains the enzyme bromelin, which breaks down protein.  Bromelin causes problems for peoples hands when they are in contact with the juice for long periods during handling.  Gloves should be worn during processing and washed each day.

The flavour of passion fruit is extremely sensitive to heat and susceptible to rapid oxidation.  It is a fine balance between ensuring that the product is fully pasteurised, while maintaining the delicate flavour.

Description/Mise en oeuvre
Production method

1. Wash whole passion fruits in clean water and discard any part of the fruit that is bad.

2. Cut the fruits in half with a stainless steel knife ad scoop out the pulp with at stainless steel spoon.

3. Extract the passion fruit juice from the pulp by liquidising the pulp at a very low speed for about 1 minute.  It is important to use a low speed to prevent chipping the seeds. Chipped seeds produce black specks in the juice that are very difficult to remove and look like dirt.  Tip the contents into a muslin cloth and squeeze out the juice, leaving the seeds behind. Liquidise the juice only, at high speed, to reduce the particle size.  This helps to reduce settling in the final product. 

4. Remove the stalks and tops from the pineapple fruit, cut off the outer cortex and pick out the eyes. Cut the fruit into small pieces, discarding any bad pieces.

5. Pulp the pineapple by liquidising or passing through a large sieve. Separate the juice from the pulp by squeezing through a muslin cloth.

6. Dissolve the sugar in the water and filter through a muslin cloth to remove any possible dirt and foreign bodies (this helps to produce a clearer, brighter juice). Heat the sugar and water to 95 C and then add the rest of the ingredients to the hot mixture.  This means that the fruit juice is heated up very quickly and so reduces the loss of the heat-sensitive flavour. Continue heating all the ingredients until the temperature reaches 90 C as quickly as possible. Hold at this temperature for 1 minute ad then start to fill into bottles.

7. Hot-fill the juice into hot, clean, sterile glass bottles.  The bottles should be heated to avoid them cracking when the hot juice is poured in.  The bottles should be filled as quickly as possible so that the remaining juice does not have to be held at this high temperature for a prolonged period and to avoid contamination as it cools down.  Wipe the lip of the bottle with clean tissue paper to ensure it is clean before the cap is placed on.  Lay the bottles on their side for 15 minutes to cool.  This is important to avoid contamination while the cap fits firmly onto the glass as the vacuum forms.

Résultats/Eléments chiffrés
Ingredients required to make mixed fruit juice

Passion fruit juice		3%
Pineapple juice			9%
Sugar				17%
Water				71%
Sodium benzoate		0.0188% (188ppm which gives 160ppm of benzoic acid)

The level of preservatives is controlled by legal limits, which vary from country to country.  Local regulations should be checked at the Bureau of Standards.

The following equipment is required;
  Bottles, crown corks and labels
  Crown corking machine
  Cooking facilities
  Stainless steel saucepan
  Thermometer
  Stainless steel cutting knife and spoon
  Wooden spoon for stirring
  Steam generator
  Cutting board
  Scales 
  Measuring cylinder
  Funnel 
  Liquidiser 
  Muslin cloth

Enseignements
  Only fresh, fully ripe fruit should be used; mouldy or insect damaged fruit should be thrown away.  All unwanted parts (dirt, skins, stones etc) should be removed.
  All equipment, surfaces and floors should be thoroughly cleaned after each day's production.
  Water quality is critical, if in doubt use boiled water or add one tablespoon of bleach to each gallon of water to sterilise it.  If water is cloudy, a water filter should be used.
  Pay particular attention to the quality of re-usable bottles, check for cracks, chips etc and wash thoroughly before using.  Always use new caps or lids.
  The concentration of preservative should be carefully controlled for correct preservation of squashes and cordials, and may be subject to local laws.  Check first and use accurate scales to measure the preservative.
  Chemical preservatives cannot be used to cover up for poor hygiene or in-sanitary conditions.  It is imperative that all equipment is thoroughly cleaned before and after use and the juices are filled into sterile containers.  Chemical preservatives are only meant to add extra protection after the products are opened when the juice may become contaminated.
  The temperature AND time of heating are critical for achieving both the correct shelf life of the drink and retaining a good colour and flavour.  A thermometer and clock are therefore needed.
  The correct weight should be filled into the bottles each time.

Auteur : Sue Azam Ali
Saisie le : 05/12/2001
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