Vacuum packing

Main concerns for food producers

From the moment of harvest or the production of a food product, the race begins against time, the main cause of quality degradation. Consumers expect healthy and minimally processed food, preferably without any artificial additives or preservatives. This forces the food producers to undertake actions that maximize the potential to protect the product’s qualities, such as taste, aroma, crunchiness and shelf life.

Food is a biologically active good. Its freshness and suitability for consumption is affected by such internal conditions as: presence of microorganisms, water activity, pH value, cellular respiration, composition, as well as external conditions: storage temperature, hygiene conditions, processing methods and gas atmosphere.

One of key elements affecting product degradation is temperature. It has a direct effect on micro-organism growth, with the greatest growth levels occurring at a temperature of 20-30 degrees Celsius. At low temperatures these harmful processes are much slower, but they cannot be eliminated (for instance in case of Pseudomonas bacteria).

Apart from low storage temperature, a popular measure for preserving quality and increasing shelf life is modified atmosphere packaging (MAP) and vacuum packaging.

Why are vacuum and modified atmosphere packaging so popular?

MAP can be defined as enclosing food in high barrier packaging, one in which the atmosphere has been modified or replaced in order to achieve an appropriate gas composition that allows the shelf life to be extended and preserves the product qualities.

This method is in general use, especially in relation to consumer packaging – which is the last stage in product manufacturing.

Paktainer packaging, bulk bags or inserts allow the technology to be employed during the resource stage, semi-finished product stage or for finished products prior to being packaged into large outer packaging, even those exceeding 2000 l. This helps to streamline the production process, conserving resources, simplifying the logistical processes and, most importantly, delivering the highest quality product to the client.

The atmosphere inside the packaging can be modified using naturally occurring gasses found in atmospheric air:

CO2 – carbon dioxide is a popular choice for modified atmosphere technology. Insects commonly found in food resources and most microorganisms, such as moulds, fungi or aerobic bacteria, are very susceptible to high concentrations of this natural gas (atmospheric air contains only 0.04% of CO2)

N – nitrogen is a neutral and stabilising gas, usually used in MAP for the removal of the oxygen inside the packaging. The process is popularly referred to as nitrogen flushing and involves a significant reduction in the oxygen content in the packaging, from 21% to 2%, for example. The nitrogen is pumped in, reducing the oxygen content.

O2 – oxygen is an undesirable gas in most cases. Oxidation causes the decomposition of vitamins or fats, for example. Unsaturated fats become rancid due to oxidation. Oxygen also allows aerobic bacteria to grow. This makes some foods turn brown, including fresh fruit. On the other hand, it helps preserve the desirable red colour of fresh meat.

Vacuum packaging is just as popular.

This involves reducing the pressure inside the packaging from 1000 hPa (atmospheric pressure) to 300-400 hPa. Of course, it is possible to generate a higher vacuum, even below 100 hPa; however, at such low pressures the forces created affect both the packaging and the packaged product, and so is rarely encountered in practice.

For those products with sharp edges, such as almonds and pistachios, or those with hard elements like plant stems, then a strong vacuum poses an increased risk of puncturing the packaging, leading to a loss of sealing and vacuum. For certain products a change in physical structure is undesirable, e.g. the breaking and fragmentation of the product which can be observed in cashews.

A vacuum allows the oxygen content to be reduced by decreasing the volume of air in the packaging.

However, even with a strong vacuum of approx. 300 hPa, the packaging still contains approx. 6% of oxygen. Values close to 2% oxygen content are practically impossible with the use of vacuum packaging. When a client requests such conditions, it is necessary to modify the atmosphere with nitrogen.

On the other hand, creating a vacuum is a cheaper process because it does not require additional gasses, and for products with a large volume it is possible to significantly decrease the size of the product and the packaging, which optimises the costs of storage and transport.

Advantages of vacuum and MAP packaging

  • Reduced micro-organism growth
  • Lowered metabolism of intact plant tissue and metabolism of post-slaughter animal tissue
  • Disrupted destructive chemical reactions, including enzymatically catalysed oxidation browning, lipid oxidation, chemical changes involving colour degradation, fish autolysis and general loss of nutritional value of food
  • Blocked moisture loss (thanks to the barrier properties of the packaging)
  • Even several times longer shelf life
  • Lowered economic loss thanks to the longer storage time
  • Decreased distribution costs, increased range of distribution and fewer deliveries required
  • Little to no chemical preservatives and fumigation agents required

Paktainer packaging with vacuum and MAP functions

Depending on the packaged product and our goals, Paktainer employs multi-layer barrier films based on EVOH and ALU based laminates.

Films with EVOH layers and PA (nylon) have low permeability to gasses such as oxygen or carbon dioxide, and are resistant to puncturing.

ALU based laminates offer a strong barrier not just to gasses but also moisture, odours and light.

Paktainer offers both bulk bags equipped with valve inserts, and the inserts themselves – which can become internal packaging for octabin, pallet boxes, or special hoods as outer packaging for already packaged products.

The packaging process in 3 easy steps

After the packaging is filled with product or the packaged product is placed in an outer packaging system such as a hood, the top of the insert has to be hermetically heat fused. This is crucial because even a small leak can lead to a loss of vacuum. The final stage involves attaching a special pump to a two-way valve attached to each package.

The special pump offers a choice between several operating protocols, and each protocol can be saved by the user.

There are generally 3 variants – generation of a specific level of vacuum, gas flushing (nitrogen or carbon dioxide) and finishing with a vacuum or gas flushing, or finishing with atmospheric pressure so that the pressures inside and outside the packaging are equal.

What does Paktainer packaging offer in terms of vacuum and modified atmosphere functions? It is not just about food products

Some examples of products which can be vacuum or MAP packaged are:

  • pistachios, peanuts, hazelnuts, cashews and dried fruit
  • herbs such as mint, sage, valerian, hemp, tea, coffee and cocoa
  • spices such as chilli, dried vegetables like garlic and onion
  • pumpkin, chia and sunflower seeds, rice and groats
  • non-food products whose volume can be reduced with the use of a vacuum
  • products from which insects are to be removed by introducing carbon dioxide
  • automotive products such as engines and other parts susceptible to corrosion, where nitrogen flushing can be used to surround sensitive components with an atmosphere nearly devoid of oxygen

Contact our sales department in order to learn more about the methods we can use to protect your products

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