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Accurate residual oxygen measurement is critical for success of Modified Atmospheric Packaging

In the old days various methods and technologies were applied to prolong the lifespan of foodstuff such as smoking, salt curing, pickling and freezing. This not only minimally increased shelf life, but also offered the consumer a slightly longer time frame within which to consume the food.

Sue Charlton | SJC Creative

Over the years various advancements in packaging have taken place from the use of preservatives, cling and vacuum wrapping to modified atmospheric packaging to enhance food longevity and freshness.

The advent of the hurried consumer who needs to pick up fresh, healthy and long-lasting produce and the retailer requiring larger stocks of fresh produce and foodstuffs are major drivers behind the need develop and embrace more innovative ways to ensure food shelf life is prolonged. Benefits to retailers come in the form of reduced wastage, increased retail life and the ability to stock large supplies of seasonal produce.

Modified Atmospheric Packaging (MAP)
The very first example of MAP occurred in 1821 when Professor Jacques Berard from France discovered that oxygen storage containers delayed the ripening of fresh fruits. Over the decades, advancements in technology has enabled the MAP concept to continually improve thereby enhancing the life-and-retail span of foodstuffs.

However, one element is critical to the successful application of MAP, that is the measurement of residual oxygen levels inside the packaging be it wrap-around sealing or insertion of foods into plastic packaging. Accurate and positive measurement from random sampling indicates that the sealing and packaging systems in place are functioning optimally.

Efficient, Precise and Accurate Solution
In addition to offering a residual oxygen measurement of a superior accuracy, Greisinger’s ResOx measurement system ensures that no damage to packaging occurs. Greisinger is part of the GHM Group of companies.

With ResOx, measurement takes place quickly and accurately by penetrating the membrane of the reinforcement sticker on the top of the package and introducing gas to the sensor by means of a pump for the measurement.

The sensor and the pump are protected from unintended penetration of the product due to its interchangeable filter. The special reinforcement sticker prevents tearing of the package and maintains a tight seal so that the penetration of environmental air is prevented, thereby eliminating a faulty measurement reading.

Jan Grobler, Managing Director of GHM Messtechnik South Africa said “With the optimised gas introduction and the special sampling pump, the necessary gas flow is minimised while the quickest possible measurement is guaranteed, which is important, in order to interfere with the product as little as possible. Particularly when packages are very small and rigid, this is the only way accurate measurement is ensured”.

A Successful Cheese sampling
Recently, Die Kӓsemacher an Austrian producer of cheese, cream cheese and a wide variety of other dairy products for the gourmet food segment applied the Greisinger ResOx measurement solution in random testing of their produce. The most common type of packaging used is film packaging in a protective gas atmosphere. The protective gas guarantees that the food lasts considerably longer and retains a higher quality.

In order to ensure safe production, random samples of the gas composition in the packaged product, for example, a package with sliced cheese must be taken at the end of the packaging process. Additionally, this test must not interfere with the closely timed cycle of 5 seconds between two finished products. Residual oxygen values are checked to ensure compliance with a defined limited value in order to ensure that the permissible residual oxygen values are not exceeded until the best before date is reached.

This is an important control step for fulfilment of the specifications for International Featured Standards Food (IFS) certification, as well as being able to certify a safe product and to gain access to sales markets with the widely recognised certification.

The measurement is also part of the Hazard Analysis and Critical Control Points (HCCP) concept with which hygienic risks can be recognised at an early stage and minimised.

Stefan Aigner, Quality Manager at Die Kӓsemacher commented “The ResOx residual oxygen measuring system from Greisinger satisfies all requirements for exact residual oxygen measurement. It has established a proven track record on a day-to-day basis in our operations. It’s low maintenance design and ease of maintenance, in particular, make this device a top choice. The downtimes experienced with comparable systems have become a thing of the past for Die Kasemacher” he said.

An additional benefit for manufacturers is the ease of adjustment of the ResOx. Inspectors can calibrate the device to the environmental air prior to each use, for example, at the beginning of a shift or batch. Therefore, the quality of the measurement is easily ensured directly on site: the oxygen concentration in the environmental air, which only deviates slightly from 20.9 vol % with adequate ventilation, is taken as a reference.

Enhanced Benefits
The ResOx residual oxygen measuring system can be applied across a vast range of foodstuffs such as breads, dried foods, seafood, fish, fruit, vegetables, bakery foods, dairy, prepared and catered foods, poultry and meats.

Benefits include:

·         Fast and reliable measurement within less than 20 seconds, which ensures a smooth production process

·         Safe food products: the control measuring device is a component of an HACCP concept and proof of product safety within the IFS scope

·         Simple on-site adjustment for daily functional testing of the device – guaranteeing reliable measurement readings

·         Simple documentation, processing and recording of adjustment data and measured data with integrated data buffer and PC software

·         Maintenance costs are minimal due to the exchange of flexible individual components

·         Customers are able to carry out maintenance themselves which ensures high availability of the device

 Overcoming Challenges through Precise Measurement
Food and produce manufacturers and retailers carry the ultimate responsibility of ensuring food safety throughout the food chain. Even the most advanced packaging and sealing systems need to conduct cheques and balances.

“The variety of prepacked foods on offer is continuing to grow, it is an ever-growing market which in its own right throws up health and safety issues in the quest to supply an economic best by date product for retailers and consumers” commented Grobler.

“The challenges that various fresh fruit and produce present varies according to commodity. Seafood and fish products have a natural water content and high-fat fish like mackerel, sardines and tuna are at increased risk if the oxidation of unsaturated fat rises above acceptable levels”.

Grobler continued “In fresh fruits and vegetables, normally the recommended oxygen in modified atmosphere packaging is between 1%-5% in order to reduce respiration rate in the produce. Fruits and vegetables will spoil very quickly if the oxygen levels are incorrect”.

“Every food line has its own unique chemical breakdown challenge. This is where our ResOx device is unrivalled in its ability to accurately and precisely measure residual oxygen levels without damage to the packaging or produce as it self-seals upon extraction. Additionally, the ResOx offers pressure compensated measurement which is particularly important for rigid packages. It also comes with an independent gas pump and has a data logger and interface” said Grobler.

The ResOx device is offered in two versions, the ResOx 5695-H residual oxygen measuring system suited for gases with elevated CO2 percentage, sensor GOEL 370, and the ResOx 5695-L residual oxygen measuring system suited for precise measuring in gases with more than 35 % vol.  or less than 0.3 % vol. O2, sensor GOEL 381. The devices and sensor are watertight (IP 65, IP 67), and offer protective armoring and backlighting.
Quick calibration is on air at the push of a button or 2-point/ 3-point calibration (air +0 % and 100 %).

“The demand for MAP is growing globally and it is no different in the Southern African market. The demand by consumers for fresh and healthily packaged food that does not expire before best by date or show evidence of deterioration or contamination is not negotiable. This is where our ResOx device makes the greatest impact in the supply chain. The measurement accuracy of the device is without question; the reliability and quality of the device is without question and the packaging after sampling returns to a ‘as before status’.  MAP is one of the most economical packaging methods available, so it would make economic sense to ensure the produce remains attractive and desirable for consumption” concluded Grobler.

Further information is available from: Jan Grobler, Managing Director, GHM Messtechnik South Africa Tel: 011 902 0158 email: [email protected]

Issued on behalf of GHM Messtechnik by: SJC Creative, Sue Charlton, Tel: 011 794 8170 Cell: 082 579 4263 email: [email protected]

Read more | Original article 

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