PINEAPPLE PROCESSING OPPORTUNITIES

PINEAPPLE PROCESSING OPPORTUNITIES1. Dehydrated

2. Vacuum packed

3. Juice

4. Fruit in syrup

5. Sweet n Sour

6. Wine

7. Vinegar

8. Jam/Marmalade

9. Crystallised

10. Bars

Protocols for dehydrated & vacuum packed finalised

Other under finalisation

Dehydrated

Introduction

Dehydrated pineapples are dried slices of pineapple fruits, which may be used as snacks or incorporated in other food preparations. They have a semi-hard and feathery texture and a sweet taste with the characteristic flavour and colour of the fruit. Dehydration preserves most of the nutritive value, compared to other processed pineapple products such as jam, jelly, marmalade or candied/crystallised fruit. The sugar content is also much less compared to the latter products.

Principles of preservation

Preservation relies on the removal of moisture by soaking in a sucrose solution, followed by drying. A sulphiting process may be used to reduce the number of micro-organisms and to prevent browning of fruits during drying and storage, thus retaining the natural colour of the fruit.

Materials required

1.6-1.8 kg of fresh pineapples (yielding (1.0 kg sliced fresh pineapple rings)

600 ml water (boiled and cooled)

240 g white sugar

0.6 g sodium metabisulphite

0.2 g citric acid

Preparation

Harvest pineapples at correct stage of maturity (80% yellow colouration) early morning and keep the fruits in shade. Transport fruits in crates, protected from the direct sun. Avoid piling fruits on the ground or in vehicles and handle the fruits with care to avoid mechanical damage.

Grade pineapples to uniform size and maturity (80% yellow coloration).

Dry wash using an air brush. Chop the top leaves, leaving part of the crown for easy handling. Remove bottom end (tail) and peel using a sharp, short and pointed knife. Carve pineapples using a sharp knife alongside the longest line of eyes.

Wash under running tap water to remove any debris. Strict personal hygiene needs to be observed now onwards.

Slice the fruit uniformly using a sharp knife or a slicer board (6-8 mm thickness)

Dip slices in chlorinated water (1 tablespoonful Eau de Javel in 3 L of water) for 3-5 minutes to reduce microbial load. Rinse under running tap water to remove excess chlorinated water

Prepare a sucrose solution using 240 g of cane sugar and 600 ml of boiled-and-cooled water. Then add 0.6 g of sodium metabisulphite and 0.2 g of citric acid to the sucrose solution. Soak the fruit slices in the sucrose solution for 18-20 hours. This process will remove almost half of the moisture, thus reducing energy cost during drying.

Remove the fruit slices, rinse under running water, and blot dry with a lint free kitchen cloth.

Arrange slices on a stainless steel plate and allow to dry at 55-60C in a ventilated oven for 18-20 hours, overturning slices after 1 2 hours of drying

Process control

The thickness of the fruit slices affects the time needed for pre-treatments such as sulphiting and sucrose dip and time needed for drying. Slices should have uniform thickness; otherwise the fruit slices will not dry uniformly to the same final moisture content. Concentration of metabisulphite solution is very important and this is controlled by the local Food Act. Temperature and duration of drying are important parameters to be monitored to get a stable and properly dried fruit.

Yield

From 1 kg of fresh pineapples, around 100 g of dehydrated slices may be obtained

Packaging and storage

Vacuum pack (73% vacuum level) in laminated bags or store in hermetic jars in a cool, dry place, away from direct light. Moisture-proof packages (such as HDPE pouches of 60( thickness) may also be used.

Shelf life

Without any preservative, a shelf life of 4 months was obtained. The use of sodium metabisulphite and citric acid increase the shelf life beyond 12 months.

Additional notes

Dried fruits may also be made from mango, banana, pawpaw, strawberry, litchi, star fruit and a range of temperate fruits like pear, peach, apricot, apple and the like. However, the drying temperate, duration of drying, concentration of sucrose solution, type of preservative and concentration of the preservative used would differ from fruit to fruit.

Dried fruits may also be mixed with crystallised/candied fruits and/or salted nuts and sold as snacks

Juice

Procedure Harvest pineapples at correct stage of maturity (80 % yellow colouration) early morning and keep the fruits in shade. Transport fruits in crates, protected from direct sun light. Avoid piling fruits on the ground or in vehicles ad handle the fruit with care to avoid bruising and mechanical damage

Grade pineapples to uniform size and maturity (80 % yellow colouration)

Dry wash using a vacuum cleaner

Chop the top leaves, leaving part of the crown for easy handling. Remove bottom end (tail) and peel using a sharp, short and pointed knife.

Carve pineapples using a sharp knife alongside the longest line of eyes

Wash under running water to remove any debris, wearing hygienic gloves

Peel and cut fruits into pieces

Extract juice using a juicer and centrifuge the mixture to collect clear juice or blend pulp and filter it through a muslin cloth to collect clear juice

Boil the juice for about 10 minutes

Fill the juice in pre-sterilised bottles (food grade plastic bottles or glass bottles)

Pasteurise the juice at 850C for 5 minutes

Seal bottles and allow to cool (do not place bottle under cold water immediately after pasteurisation since the bottles may crack) Store in a cool and dry place, away from direct light

Yield:

1kg of pineapples yield around 450-500mL of pure undiluted juice

Shelf-life:

4 months

Note:

Through the use of an acid regulator (citric acid) and preservative (sodium benzoate), a shelf-life of 1 year may be obtained.

Sweet n sour

To make 1kg of pickleIngredients: 1kg (2lb) fresh pineapple

20g cloves

20g stick cinnamon

5g fresh ginger-root

750g brown sugar

300ml white vinegar

Procedure:

1. Tie the cloves, cinnamon and ginger in a piece of muslin cloth to make a spice bag

2. Boil the sugar in the vinegar with the spice bag for 10 minutes or until a syrup is formed

3. Pour the syrup over the fruit and let stand overnight

4. Drain off the syrup

5. Boil the syrup for 10 minutes

6. Add the fruits to it and cook, uncovered until just tender

7. Seal in hot, sterilised jars

8. Pasteurise the product for at least 15 minutes in boiling water (83(C). Shelf life:1 year

Fruit in syrup

Ingredients for one 250 ml jar 15g sugar

140-160 g pineapple dices

Water

Procedure Harvest pineapples at correct stage of maturity (80% yellow colouration) early morning and keep the fruits in shade. Transport fruits in crates, protected from the direct sun. Avoid piling fruits on the ground or in vehicles and handle the fruits with care to avoid bruising and mechanical damage.

Grade pineapples to uniform size and maturity (80% yellow coloration).

Dry wash using a vacuum cleaner. Chop the top leaves, leaving part of the crown for easy handling. Remove bottom end (tail) and peel using a sharp, short and pointed knife. Carve pineapples using a sharp knife alongside the longest line of eyes.

Wash under running tap water to remove any debris, wearing hygienic gloves.

Cut uniformly into 25mm x 15mm x 15mm dices

Dip dices in chlorinated water (200 ppm) solution for 3-5 minutes to reduce microbial load. Rinse under running tap water to remove any surface chlorinated water.

Put the dices in a presterilised jar

Add 15g of white sugar to a 250 ml jar filled with pineapple dices. Cover the dices with water which has been boiled and then cooled. Do not mix so as to allow the sugar to dissolve gradually and allow the pineapple to keep its natural taste.

Cover the jars with their lids and seal (do not seal tightly, however)

Pasteurise the product by submerging the jars in a container which is filled with cold water and allow them to boil on medium heat.

As soon as the water in the container starts boiling, leave the jars for another 8-10 minutes

Remove the jars from the container and seal them completely

Turn the jars upside down and leave them for 24 hours

Store in a cool dry place away from direct light.

200 ppm ~ 6 ml of % active chlorine solution in 1 litre of water (please add 0.3 g of citric acid per litre of water to make the chlorinated water more effective against microbes)Shelf lifeOne yearWine

Procedure

Grade the pineapples

Select good quality pineapples

Cut into small pieces

Dip in chlorinated water for 3 to 5 minutes

Wash under running tap water

Blend pulp and peel using an electric blender

Mix pulp with boiled and cooled water in the ratio 1:2.5

Adjust pH (if necessary) to 4.0 using NaHCO3 Adjust Brix to 18-20o Activate yeast separately (Add 2.7 g of yeast to 50 ml of boiled and cooled water and then add 0.14 g of NH4NO3)**

Pasteurise pineapple juice (at least 5 minutes at 85oC)

Inoculate 950 ml juice with yeast from ** above

Allow to ferment anaerobically for 7-9 days until no bubbles of CO2 is seen Mature wine in Bois de Chene barrels preferably or in plastic/glass containers (low temperature and high relative humidity). An alternative way of maturation is to put the wine in glassware containing oak wood chips (wood of size 10 x 10 x 30 mm). Two wood chips may be added per 300g jar of wine.

Shelf life

Under investigation VINEGAR

Procedure Grade the pineapples

Select good quality pineapples

Cut into small pieces

Dip in chlorinated water for 3 to 5 minutes

Wash under running tap water

Blend pulp and peel using an electric blender

Mix pulp with boiled and cooled water in the ratio 1:2.5

Adjust pH (if necessary) to 4.0 using NaHCO3 Adjust Brix to 18-20o Activate yeast separately (Add 2.7 g of yeast to 50 ml of boiled and cooled water and then add 0.14 g of NH4NO3)**

Pasteurise pineapple juice (at least 5 minutes at 85oC)

Inoculate 950 ml juice with yeast from ** above

Allow to ferment anaerobically for 7-9 days until no bubbles of CO2 is seen. Dilute pineapple wine to 8o alcohol

Add 150 ml inoculant (Acetobacter sp. ) to 750 ml of diluted wine

Add 0.14g of ammonium sulphate per litre of wine

Allow to ferment aerobically for 9-15 days

Filter through activated charcoal on filter paper

Fill in pre-sterilised bottles

Flash-pasteurise at 60oC

Yield:From 1 kg of Victoria pineapple, around 450 ml of pure pineapple vinegar can be obtained. To render pineapple vinegar-making more economically viable, dilution with water can be done (dilution factor of 2). Thus, almost 900 ml of vinegar could be produced from 1 kg of pineapple. However, sugar needs to be added to bring % sucrose of diluted solution to 18-20% before alcoholic fermentation starts.Shelf-life:Under investigation

FRUIT BAR

Procedure

Harvest pineapples at correct stage of maturity (60- 80% yellow colouration) early morning and keep the fruits in shade. Transport fruits in crates, protected from direct sun light.

Grade pineapples to uniform size and maturity (80 % yellow colouration)

Dry wash using a vacuum cleaner

Chop the top leaves, leaving part of the crown for easy handling. Remove bottom end (tail) and peel using a sharp, short and pointed knife.

Carve pineapples using a sharp knife alongside the longest line of eyes

Wash under running water to remove any debris, wearing hygienic gloves

Peel and cut fruits into pieces

Blend pineapple pulp to a fine paste.

Cook pulp on low heat till paste thickens (for 20 minutes at 80C)

Add of the sugar required (65% w/w basis) to the pulp and continue cooking for further 10 minutes.

In a separate container, mix pectin (4% w/w basis) with the remaining sugar

Add the mixture gradually to the paste and cook for further 40-50 minutes until it thickens

Mould the paste in a stainless steel plate

Put the plate in a ventilated oven at 55 oC for 28 hours

Cut the paste into cubes

Coat the product with finely ground cane sugar

Pack in hermetic jars

Shelf-life8 months