Gas Analysis – Inspection of Modified Atmosphere Packaging (MAP)

Manufacturers of sensitive and perishable products face the key challenge of ensuring maximum product quality throughout the entire product lifecycle. Modified Atmosphere Packaging preserves freshness, flavor, and texture and significantly extends shelf life.

In the food and beverage industry, Modified Atmosphere Packaging (MAP) has long been established as the gold standard.

The KRÜSS Optronic MAT Series gas analysers are designed to measure various gas mixtures containing N2, CO2, and O2.

To select the best possible measurement device, it is important to know the specific protective gases and applications.

Contents

Info on N2 Nitrogen Modified Atmosphere Packaging (MAP)

Protective gas: Nitrogen (N2)

Nitrogen makes up about 78% of the air. It is an inert gas and therefore does not react directly with the food. As a packing gas, it is used primarily to displace oxygen from the air. This indirectly prevents the oxidation of food and inhibits the growth of oxygen-dependent (aerobic) microorganisms.

Modified Atmosphere Packaging: CO2 protective gas function

Protective gas: Carbon Dioxide (CO2)

Carbon dioxide is a key protective gas: It lowers the pH of the product environment, reduces mold and bacterial growth, and affects the permeability of cell membranes. However, the concentration must be chosen precisely, as too much CO2 alters the taste. Furthermore, because it is highly soluble in both fat and water, the print on the packaging may fade.

Modified Atmosphere Packaging: Protective Gas and O2 Information

Protective gas: Oxygen (O2)

Oxygen makes up about 21 % of the air and enables the growth of aerobic microorganisms—at the same time, it accelerates oxidative spoilage. In modified atmospheres, O2 is therefore significantly reduced or completely removed. Fresh red meat is an exception: In this case, the oxygen content is deliberately increased to preserve or intensify the red color.

How does Modified Atmosphere Packaging (MAP) work?

Replacement of the ambient air inside the package

In Modified Atmosphere Packaging (MAP), various gas mixtures consisting of nitrogen (N2), carbon dioxide (CO2), and oxygen (O2) are used. These protective gases also occur naturally as components of air.

Modified Atmosphere Packaging: Simply put, the natural ambient air inside the package is replaced with a modified gas mixture. The concentrations of the protective gases N2, CO2, and O2 are applied in different proportions, depending on the requirements and the product.

These modified gas mixtures are subject to constant monitoring, both on the packaging line and in the laboratory or during distribution. Quality assurance is carried out using gas analysers.

Modified Atmosphere Packaging requires absolute measurement accuracy, which is why our MAT series relies on modern, high-performance sensor technology. The models use electrochemical O2 cells (EC), non-dispersive infrared sensors (NDIR), and even zirconium dioxide sensors (ZrO2) for measurement. All versions operate with extreme precision and require only minimal sample volumes of 3–7 ml.

The MAT1400 and MAT1500 models combine NDIR technology with a highly sensitive ZrO2 sensor it is ideal for demanding measurement tasks.

How it works, using a (ZrO2) sensor as an example: A yttrium-doped ZrO2 membrane heated to 750°C separates the measured gas from the ambient air. Oxygen ions migrate toward the side with the lower O2 concentration. A platinum film on both sides detects the resulting voltage difference. Electrodes are used to measure the voltage between the two sides of the membrane in order to calculate the oxygen concentration.

Sensor Technology: Gas Analysers

To ensure optimal adaptation to the specific application, various models with different sensor technologies are available as options. For each specific application and process, the appropriate, proven sensor technology should be selected. The range of available sensors allows for optimal customization in terms of measurement range and accuracy:

Electrochemical cell (EC) for O2 measurement
Zirconium dioxide (ZrO2) cell for O2 measurement
Non-dispersive infrared sensor (NDIR) for CO2 measurement

The following table provides an initial overview. We’d be happy to discuss which device models are best suited to your specific needs during a personal consultation.

Please feel free to contact us if you need further assistance.

Gas Analyser	MAT1100 Model	MAT1200 Model	MAT 1400 Model	MAT1500 Model
Area of application	Sporadic O2 random sample inspection	Combined O2 and CO2 Measurement	High sample volume or high O2 concentration	High sample volume or high O2 concentration + Combined O2/CO2 measurement
Advantage of the model variant	Cost-effective option, quick to deploy, low drift	Cost-effective option, low drift, environmentally compensated CO2 measurement	Long service life, fast measurement, high precision even at the lowest O2 concentrations, wide measurement range, drift-free	Long service life, fast measurement, high precision at extremely low O2 concentrations, wide measurement range, ZrO2: drift-free, NDIR: drift-free, environmentally compensated CO2 measurement
O2 Sensor Technology	Electrochemical oxygen cell (EC)	Electrochemical oxygen cell (EC)	Zirconium dioxide sensor (ZrO2)	Zirconium dioxide sensor (ZrO2)
CO2 Sensor Technology	– – –	Non-dispersive infrared (NIR) sensor	– – –	Non-dispersive infrared (NIR) sensor
N2 Sensor Technology	– – –	Arithmetic Calculation	– – –	Arithmetic Calculation

Modified Atmosphere Testing – Examples

Modified atmosphere packaging prevents oxidation in spices, snacks, nuts, and coffee

MAT1100 ensures freshness

Snacks, nuts, spices, and coffee stay fresh longer when their high fat content is protected from oxidation. That is exactly what a package in a pure nitrogen atmosphere does: it displaces oxygen and prevents rancidity. The modified atmosphere provides quick, economical control. MAT1100 is the ideal choice and a compact gas analyser for reliable quality assurance.

Modified Atmosphere Packaging Ensures the Quality of Baby Food

Exactly. Quick. MAT1400.

To ensure the shelf life of powdered milk—especially delicate baby formula—oxygen is systematically removed from the package. In practice, bottling is usually carried out under pure nitrogen with minimal residual oxygen. To ensure the highly reliable monitoring required here, the quality assurance department relies on the MAT1400 gas analyser.

Sustainability of Modified Atmosphere Packaging for Organic Meat

MAT1500 in application range No. 1

Fresh organic meat products benefit from Modified Atmosphere Packaging, which doubles or triples their shelf life without compromising quality—thereby reducing waste and packaging materials. For precise monitoring, the industry relies on the MAT1500, which is ideal for fresh meat with 70–80 % O2 and 20–30 % CO2 thanks to its ZrO2 and NDIR sensors.

Modified Atmosphere Packaging (MAP) Profiles & Industries

Every industry uses its own specific inert gas mixtures: In addition to the food industry, gas analysers are also used in quality assurance in the electronics, pharmaceutical, and cosmetics industries.

Each industry uses different mixtures for its respective protective gas. Depending on the intended use, different concentrations are therefore used.

For example, there are pure nitrogen flushing methods or equilibrium modified atmospheres (EMA) for packaged fruits and vegetables that have been prepared or cut. Below is an overview of possible gas mixtures used in various industries.

Overview of Modified Atmosphere Packaging (MAP) Gases & Industries

Overview of Applications

Gas analysers are indispensable devices in modern packaging processes: Here’s where these analysers are used:

Random measurements on the production line during the packaging process
Inspection following a revision: Change in film or packaging materials
Modification to the packaging machine: Sealing seams, welded seams
Retained samples, quality assurance in the laboratory
Inspections during transit

Below is a comprehensive overview of sectors and industries that use gas analysis. You’ll also learn which MAT model is suitable for which application.

Overview of Applications & Models

Calibration and Adjustment

https://youtu.be/s-8BJMf8o4U

Test results for Modified Atmosphere Packaging must be traceable. Traceability refers to the verifiable and seamless verification of measurement results through comparison with a recognized standard.

In our gas analysers, this is achieved using high-quality reference materials such as test and calibration gas mixtures. This ensures that a measurement device is ready for use without any deviation from the standard.

You can also use our maintenance service for technical inspections of components, adjustment of gas analysers, and subsequent audit-compliant calibration. This ensures that your device will continue to deliver measurement results over a long period of use, with documented traceability and in accordance with recognized standards.