Fruit and Vegetable Juice Processing In Kenya

Fruits and vegetables can be categorised into soft pulpy e.g papaya, mango, peaches, avocado, tomato and hard e.g apples, pears, carrots, beetroot . Whilst most hard fruits/veg can be processed into both clarified “clear” juices as well as “nectar” pulp juices, soft pulpy fruits/veg are not so easy to produce clarified juices and are more commonly processed into fruit/veg nectars. Almost all juices can be turned into concentrates.

Selection of fruit/veg to use for juice is very important. They must be mature, clean and free from any mould, bruising or rot, they must also not contain any chemical or other contaminant residues.

Processing facility

It is important to select a clean working space to process fruit and vegetables. This space may be in the form of a small kitchen, a small production facility or a larger processing facility.
The facility must ensure the following:
  • A potable water supply including hot water. 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.
  • Preferably electricity
  • Screened windows and doors to reduce insects
  • No horizontal ledges, window sills, or rafters where dust, insects and bird droppings can collect.
  • Clean hard surface preferably steel working surfaces
  • Separate storage area for chemicals, packaging materials and cleaning materials
  • Sloping concrete floor
  • Proper drainage for washing down each day
The processing area must be set up logically to ensure there is no risk of cross contamination within the processing space and operations.

Juicing step-by-step

1. Pre sorting – Fruit/veg arrives into a processing area by many means and in many packaging forms. Pre sorting ensures rotten and poor quality products are removed in the very early initial stages of processing. It is wise that this process of pre sorting happens outside of the hygienic confines of the production area to ensure there is no risk of cross contamination. Pre sorting personnel must also be subject to the hygienic regulations of the facility and must ensure that they do not create cross contamination via unwashed hands, dirty overalls or clothing and footware.

 2. Washing – Washing of fruit/veg is carried out to remove all external debris and contamination. This is commonly the initial process carried out within the confines of the production facility and often food grade sanitising chemicals are used as sterilising agents.

 3. Sorting – A final sorting is done to ensure there are no internal contaminants e;g worms or other bugs. For optimum efficiency this operation is carried out on sorting tables or moving inspection conveyor belts within the production facility.

 4. Peeling and Seed removal – Depending on the scale of production, some fruits/veg require skins and seeds to be removed before processing: e.g. Mangoes, peaches, papaya, pineapples, avocado.

 5. Cutting – Depending on the scale of production and machinery used for processing, some fruit/veg require cutting into optimal sizes for machinery or process used: e.g. mango, carrot, beetroot.

Manual Juice Making

This is a basic form of making juice without the help of any electrical machinery. The process is labour intensive and sometimes a less efficient extraction method.

After steps 1 – 5 above, the following processes are carried out, depending on the fruit/veg type.

1. Squeezing or pressing

Fruit/veg are squeezed or pressed using manual appliances. This system is efficient for very small scale restaurant production where volumes required are not very high. In the case of citrus, skins are not removed.

2. Sieving/Pulping

This manual system is used for fruit/veg with small seeds e.g passion fruits.

Small scale fruit/vegetable juice production using electric appliances

Steps 1 – 5 are followed as above before fruit/veg are subject to crushing, grinding or disintegration using various electrical appliances.

1. Disintegration through process of blending 

Soft fruits/veg may be blended using commercial blenders resulting more often in “nectars” where the pulp remains in the final product. Fruits/veg processed like this often include mango, pineapple, papaya,tomato, avocado etc and also many combinations of these creating fruit “mixes” or “smoothies”.

2. Crushing Juicy fruits with small seeds are often put through a process of crushing where the seeds, skins and unwanted pulp are removed from the final process.

3. Grinding Juices of fruits such as apples and pears are extracted through the process of grinding.

4. Centrifugation Centrifugation achieves a separation of particles in suspension in the juice. Many electric juices use this principle where fruit mass is spun at speeds of 6000 to 6500 RPM (rotations per minute) through a sieve that retains the seeds and unwanted pulp mass. Centrifugation can be considered as a pre-clarifying step.

Commercial juicers crushes, grinds and centrifuges – especially good for pineapples and passion fruit. Fruit is pushed through the feeding mouth of the machine and is pulverised on a rotating disc before the pulp is spun against a very fine filter, thus fruits normally needing grinding and crushing can be juiced. The seeds and pulp are expelled from the side shute on the machine.

N.B Citrus fruit are normally juiced using special citrus juicers as their skins contain oils that will create the juice to taste bitter. There are many types of electric citrus juicers on the market ranging from domestic use to commercial.

Domestic citrus juicer good for limes, lemons, oranges, tangerines etc.
When buying juicing machinery, be sure to look for models that produce a good yield of juice. The efficiencies of machines can have a huge impact on yield and thus potential income.

For further information on machinery and utensils click here

Maximising on fruit extraction efficiency, colour, clarification and taste

1. Enzyme treatment -To improve extraction yield , taste and colour fix of some juices, enzyme treatment with 2 – 8% pectolitic enzymes is used at 50oC for 30 minutes.
However, for fruit which is naturally rich in pectic substances e.g citrus, this treatment makes the resulting “exhausted” material useless for industrial pectin production.
2. Heating of crushed fruit mass before juice extraction is an optional step used for some fruit in order to facilitate pressing and colour fixing; at same time, protein coagulation takes place.
3. Juice Clarification – can be performed by centrifugation or by enzyme treatment. Centrifugation achieves a separation of particles in suspension in the juice and can be considered as a pre-clarifying step. This operation is carried out in centrifugal separators with a speed of 6000 to 6500 RPM.
4. Enzyme clarifying is based on pectic substance hydrolysis; this will decrease the juices’ viscosity and facilitate their filtration. The treatment is the addition of pectolitic enzyme preparations in a quantity of 0.5 to 2 g/l and will last 2 to 6 hours at room temperature, or less than 2 hours at 50deg C, a temperature that must not be exceeded.
The control of this operation is done by checking the decrease in juice viscosity. Sometimes, the enzyme clarifying is completed with the step called “sticking” by the addition of 5 – 8 g/hl of food grade gelatine which generates a flocculation of particles in suspension by the action of tannins.
5. Filtration of clarified juice can be carried out with kieselgur and bentonite as filtration additive in press-filters (equipment).
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