Packaging can be the single most expensive cost, particularly with non-returnable containers made of wood or cardboard. The benefits of packaging must clearly justify the investment. A great variety of materials are used for the packing of perishable commodities.

They include wood, bamboo, rigid and foam plastic, solid cardboard and corrugated fibre board. The kind of material or structure adopted depends on the method of perforation, the distance to its destination, the value of the product and the requirement of the market.

CFBC Boxes

Corrugated fiberboard is the most widely used material for fruit & vegetable packages because of the following characteristics:

Light in weight
Reasonably strong
Flexibility of shape and size
Easy to store and use
Good pointing capability vi .Economical

Wooden Boxes

Materials used for manufacture of wooden boxes include natural wood and industrially manufactured wood based sheet materials.

Sacks

Sacks are traditionally made from jute fibre or similar natural materials. Most jute sacks are provided in a plain weave. For one ton transportation of vegetables, materials of 250 grams per square meter or less are used.

Natural fibre sacks have in many cases been replaced by sacks made of synthetic materials and paper due to cost factors, appearance, mechanical properties and risk of infestation and spreading of insects.

Sacks made of polypropylene of type plain weave are extensively used for root vegetables. The most common fabric weight is 70-80 grams per square meter.

Palletisation

Pallets are widely used for the transport of fruit and vegetable packages in developed countries.

The advantages of handling packages on pallets are:

Labour cost in handling is greatly reduced
Transport cost is reduced.
Goods are protected and damage reduced.
Mechanized handling is very rapid.
Through high stacking, storage space can be more efficiently used.
Pallets encourage the introduction of standard package sizes.

Packaging Films

The packaging industry has become increasingly responsive to the specific gas requirements of fresh produce and is now providing films tailored to the requirements of given types of fresh produce.

Films are available for commodities having low, medium and high respiration rates. The oxygen transmission rates of the films are matched to the minimum level of O₂ required for the produce to retain its quality.

Modified Atmosphere Packaging Films

Modified atmosphere packaging (MAP) employs packaging films to manipulate the respiration rates of fresh produce and thereby extend shelf life.

MAP makes use of the carbon dioxide produced by respiration and oxygen consumed during the respiration process, for the production of an environment within the package that slows the metabolic activity of the produce.

The goal of MAP is to create an equilibrium atmosphere, such that the oxygen concentration is adequately low and the carbon dioxide concentration is adequately high, to be beneficial and not injurious to the produce.

Packaging films such as low density polyethylene, which can be easily sealed and offer good permeability to O₂ and CO₂, are durable at low temperatures and which have good tearing resistance, are appropriate in use for MAP.

MAP films can be impregnated with minerals in order to absorb and remove ethylene produced in the storage environment around the bagged produce.

Impregnated MAP films are particularly suitable for transporting bulk fresh fruit and vegetables to distant markets or between farmers and consumers at supermarkets and retail outlets.

Produce contained in MAP must be maintained under appropriate temperature conditions and must be properly handled and packaged prior to transport if freshness is to be maintained, shelf life extended and safety assured.

Neither low temperature nor MAP can act alone to deliver full value to the consumer, the reason being that both factors work together to slow the metabolism and aging of the produce thereby extending the shelf life and maintaining the quality.

Key Considerations when Selecting Packaging Materials Suitable for Fresh Produce

Container dimensions – Containers must be of the appropriate weight and measurements. They can be altered to suit the needs of the handler and the produce item.

For example, tomato boxes must be 39cm long and 25cm wide, with 3.5cm raised corners such as triangular corner supports to increase the strength of the carton.

Ventilation – Fresh-air exchange helps prevent unwanted ripening and the accumulation of odours, and ensures longer shelf life for many perishables.

Holes within the packaging facilitate both horizontal and vertical airflow, thereby facilitating cooling of the produce. Temperature management can be difficult if packing materials block ventilation holes

Ease of handling – The weight and size of boxes must facilitate easy handling.

Compliance with standard design and marketing demand – The specific packaging requirements of buyers must be taken into account during the selection of packaging materials. Many supermarket chains differentiate themselves from others through uniquepacking or branding.

Chemicals that are banned in certain importing countries may not be used in packaging. In fact, a number of importing countries now stipulate that packaging must be recyclable and must clearly identify the product and its origin so that it can be traced back to its source.

Packaging Material Design must include Holes (5 per cent) for Ventilation

Packaging Materials and Modified Atmosphere Packaging Films

Ease of palletisation – cartons are the primary form of outer packaging used for the international export of fruit. Pallets provide a strong base for transporting and storing cartons that weigh up to 1 ton.

The stacking pattern of palletised cartons is dependent on the height of the carton and the positioning of the ventilation holes. Pallets must be constructed from environmentally friendly materials and must comply with the standards of the exporting and importing countries.

Effective as of 2005, all packaging material made of wood must be either heat- or chemically-treated to comply with international standards.

The following basic care must be taken during palletisation:

– Surface finish – the surface of the package must be smooth in order to prevent damage to the produce

– Easy of cleaning – packaging must be easily cleaned if it is to be re-used

Packaging materials for produce destined for local markets

Woven plastic packaging provide the following advantages;

Withstands impact;
Provides protection against insects if closely woven;
Is somewhat effective in preventing contamination; and
Does not absorb moisture.

Advantage of fibreboard is;

Provision of some protection against insects.

Advantages of plastic crates are;

Withstand impact during transportation;
Can be easily be stacked and palletized;
Offer some protection against contamination.

Jute bags have the following advantages;

Provide good protection against impact damage;
Do not absorb moisture;
Are biodegradable; and
Retain produce odour.

Corrugated Cardboard Boxes

Withstand impact forces and localise the produce;
If they are waxed, provide protection against moisture and humid environments;
Contribute to prevention of produce contamination; and
Are stackable and can be palletised during transportation.

Packaging materials for produce destined for long-distance and export markets

Bulk Bins

Bulk bins (1000 x 1200mm), which are capable of carrying 300kg of fruit, are used for the export of produce items such as oranges for juicing.

Bulk bins can be stacked on top of each other and fastened with securing strips. The combined weight of the bins must be less than 100 kg

Cartons

Fruit cartons made from corrugated cardboard, polystyrene and polypropylene are used for the export of fresh produce. The packaging container must comply with standards set by the exporting and importing country.

Cartons must be strong enough to bear the weight of the produce, must either be waxed or should not absorb moisture easily and should be adequately ventilated so as to allow horizontal and vertical airflow.

The number of cartons stacked on a pallet is dependent on the size and depth of the cartons.

For example, a total of 75 cartons measuring 600 x 400 x 120mm can be stacked on a 2.1m pallet, while 260 cartons measuring 400 x 300 x 70 mm can be accommodated on a pallet stacked to a similar height.

Each carton may contain fruit packaged in small units or secondary packaging units such as fruit wrappers, plastic bags, nettings or punnets. Nets offer the advantage of allowing the fruit to breathe freely.

Read Also : 5 Types of Produce Packages and Packing Techniques

Punnets are generally made of polypropylene or polyethylene and are used for the packaging of small fruits such as plums, apricots and grapes. Some buyers require that grapes be packed in polycot, carry or zip lock‘ bags.

Labeling

Labeling helps handlers to keep track of the produce as it moves through the horticultural supply chain.

Labeling assists the wholesale agents and retailers in using proper practices. Labels are pre-printed or glued, stamped or stenciled on to the packaging container.

The label must mention the following:

Count, cultivar, class type or size;
Weight;
Producer‘s code;
Pack house code;
Name and address of the exporting packer;
Country of origin;
Any special treatment given e.g. SO₂ fumigation or type of approved wax or pesticides used etc.; and
Recommended storage temperature and special handling instructions