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KitchenTown & MULTIVAC: An overview on Modified Atmosphere Packaging (MAP)

KitchenTown & MULTIVAC: An overview on Modified Atmosphere Packaging (MAP)

There’s a huge variety of products being developed in our KitchenTown Development Area.  

Each Product has specific requirements and for each product we need to test several options- to reach the best possible solution in development, we as KitchenTown support with our knowledge as food-scientists and a development area to test and try out your newly developed recipes. The KitchenTown Development Area already has an assortment of equipment for the product development process, but some requirements are more special. At this point, we are happy to have great partners supporting with their specific knowledge and equipment.  

One great example is the support of MULTIVAC and AirProducts for our Member Krumbs.  

Krumbs describes themselves as the “Nespresso for the toaster”. Their mission is to bring the highest craftmanship home to their customers, by dedicating their work to the creation of a completely new product category in the field of baked goods and “convenient snacking”. They develop sustainable “clean label” products for home toasters and thus turn the most popular kitchen appliance into a home baking station. Their goal is to become the industry leader in premium quality combined with maximum sustainability. 

Especially in the category of baked goods, food waste is one of the major problems companies are facing. The longer we can store products, the less food-waste we will have to deal with. To develop long-lasting clean label products like the ones of Krumbs, we work with modified atmosphere. Modified Atmosphere is one option to extend shelf life. As we haven’t had the right equipment ourselves to make valid tests in this category, we got supported by MULTIVAC, by providing us with their C 200 to be able to start with the product development together with Krumbs. Air Products delivered a gas mixture of CO2 and N2 right the next day. 

We will try to give you a rough overview on options, that you have using MAP, how to deal with it and what’s possible and what not. Obviously, this is a huge topic. Many foods we eat on a daily basis are packed with modified atmosphere.  

Why modify the atmosphere? 

Regarding the shelf life we must deal with different intrinsic and extrinsic factors. Intrinsic factors might be pH, water activity, preservatives, contamination from through ingredients or processes. Extrinsic could be the storage temperature and package atmosphere.  

This packaging atmosphere, if not modified consists of approximately 21% oxygen, 78% nitrogen, less than 1% argon, small amounts of neon, helium, krypton and xenon, and less than 0.1% carbon dioxide, as well as aerosols such as water vapor. So, what we do modify is the composition of the gases, which get in contact with the packaged food product.  

Which gases are used and why?  

Oxygen:  The impact of oxygen- leading to altering of value-giving ingredients and results in quality losses such as loss of aroma substances and vitamins, formation of off-flavors, structural changes due to oxidation of proteins- is mostly negative. Due to that, in many food products, we actually want to get rid of any oxygen.  

But there’s an impact on microbes: Some will be inhibited in growth by higher amounts of O2- also, meat will look redder for longer, when packed in high O2 Packaging.  

Nitrogen:  Nitrogen is an inert gas. It can be used to displace atmospheric gas mix- also, it prevents the package from collapsing- which can happen, when too much CO2 is used as Nitrogen diffuses slower through the packaging.  

Carbon Dioxide: Carbon Dioxide is mainly used in Modified Atmosphere Packaging, it can inhibit some bacterial spoilage, even the bacteriostatic effect is still quiet unknown. This gas is soluble in water and lipids and through this acidify your product with a direct antimicrobial effect- this might not be wanted in every product, as it can reason a bitter sour taste. Especially in high fat products.  

Other: Also used in Packaging are Argon and Nitrous Oxide Also, Sulfur Dioxide, Carbon Monoxide or Choline Oxide might be used in amounts below 1% - for the moment more in research, as these aren’t allowed for foods in EU countries.  

How to find the right mixture 

There is data about the mixes of gas used for different purposes. AirProducts provide some of the common mixtures for several product on their website: and also our partner mulitvac can provide Information. 

But if we develop innovative products, this is often not enough. We must double check on ingredients and potential spoilage. For most spoilage microorganisms, we know, in which raw material they appear. Depending on the process, pH-value and so on, we know, what kind of microorganisms we must deal with after processing and packing.  

For example, after baking a bread: In bakery products this will mainly be molds, as the products are being contaminated while cooling down or being packed. Most molds can’t grow under 0,1% oxygen. In industrial production, we won’t reach that point, unless we add O2 absorber. But regarding MAP, CO2 can inhibit growth of mold, as it’s over 50% of the mixture.  

Bacillus subtilits from flour might still occur, if the product is baked to weak the spores are still in the product. This can be controlled by using sourdough and have a low pH in product. Also, these can be inhibited by CO2 

This information is based on the majority observations in a variety of studies. Depending on storage temperature, packaging materials and specific product matrix, these can differ. You will be able to find studies, where scientists observed enhanced growth of different kind of yeasts or molds.  

 Anything else?  

Yesss, there are many more things, to take care of depending on the individual product, let’s get some on the table here:  

  • CO2 will be soluble high fat or high moisture foods- what we don’t want, is any H2CO3 – off flavour (Sour/bitter/metal) in our foods.  
  • The solubility of CO2 increases with decreasing temperature, which is why temperature has a major influence on the effectiveness of MAP over the storage period for packages containing CO2. 
  • This, and also the faster permeating CO2 compared to the from outside to inside permeating O2 leads to collapse of the packaging, as there is less CO2 in the free space. This is why adding N2 is necessary 
  • The packaging should be designed so that the gas can circulate well to the product surface, and a ratio of product volume to packaging atmosphere volume of 1:1.5-2 is also recommended 
  • When we work with MAP in processes, we will not get rid of all of the oxygen. This might not be needed, as discussed before, CO2 can also inhibit growth. If needed, there are active packaging solutions, that contain O2 absorbers or similar, that can be useful in the case you need less than 1% CO2.  

And most important: MAP on its own is not the solution:  

MAP can only inhibit growth of microbes on a product: Whenever a highly contaminated product is packed, maybe because staff might not be trained well, it might not help a lot. There can also occur mistakes in packaging and sealing, gas mixture and so on, which might lead to some products being not stable in their atmosphere.  

As stated in the beginning MAP can only be one of the hurdles to prevent spoilage- keep the other ones in mind: storage temperature, pH, moisture and water activity, heat-, pressure-, radiation-treatments and so on.  

And now: How to pack that?  

Regarding Packaging Solutions that can keep a gas barrier, there is still a lot to do regarding a better recyclability. The commonly used material that is available is PET/PE/ EVOH- but producers are coming up with new solutions and mono materials for improved recyclability. Also, a quite often used option is less usage of material for example by using trays made from carton, that gives the customer the opportunity to use less plastic and separate for recycling. If you interested to have a closer look at this topic- check the sustainability solutions MULTIVAC can provide, be it usage of less packaging material at all, paper solutions, recyclable plastics/ mono material packagings.  

The less packaging material the better, but keep in mind: the actual sense of packaging is to keep the product stable. Usually- as there are no blank statements possible here, the negative impact of wasted food is much higher, than using a recyclable (or even reusable) packaging solution to keep food fresh longer.  

There are different ways of packing in MAP. One is gas-flushing: In the continuous gas purging method, a stream of gas is introduced into the package, and the package is sealed as soon as a large part of the gas has been exchanged. 

In the compensation vacuum process, the air is extracted first, and only then is the desired gas mixture added. The process is two-stage, which requires more time than the gas flushing method, but the efficiency in terms of residual oxygen is higher. With our C 200 that is provided by MULTIVAC we test this product- but nevertheless- for our start-ups scaling up MULTIVAC provides all varieties and sizes of MAP Machines.  

Validation & Storage Tests 

Also, we now tried to find the best solution, via research, we still need to check. Some points studies are still not perfectly clear regarding inhabitation of spoilage.  We need to make tests. And we need to measure:  

  •  sensory, microbial growth, pH development, moisture transfer and so on. Storage tests are needed to guarantee, that your product will be received by the customer, the same state, as your company stands for.  

We need to improve again and again- this might be packaging, storage conditions but also recipe and process, as we do in any new product development.  

Want to know more about MULTIVAC’s applications in the sector of alt-proteins? Click here!

Ready to scale?  

And whenever you are ready to get your product upscaled MULTIVAC has several solutions- from a small tabletop version to industry solutions.  

MULTIVAC Deutschland GmbH & Co. KG Bahnhofstraße 4 87787 Wolfertschwenden 
Tel.: +49 8334 601-0 Fax: +49 8334 601-199 

This short article can’t represent all aspects of modified atmosphere packaging- but maybe it’s a good overview, what you need to think about and: Who wants to read boring papers about microbiology? This is, what we at KitchenTown are here for: If you need more deep dive support on this topic, questions regarding specific product categories, or if you have any feedback or new insights on this article please reach out to:  

  • Buchner, N. Verpackung von Lebensmitteln. Berlin, Heidelberg, New York : Springer, 1999. 
  • Blakistone, B. Introduction. Principles and Applications of Modified Atmosphere Packaging of Foods. Gaithersburg : Aspen Publishers, 1999,  
  • Smith, J.P. and Simpson, B.K. Modified Atmosphere Packaging of Bakery and Pasta Products. [book auth.] J.M. Farber and K. Dodds. Packaging, Principles of Modified-Atmosphere and Sous Vide Product. Lancaster Basel : Technomic, 1995. 
  • Weber, H. Mikrobiologische Aspekte bei der Verpackung von Lebensmitteln. Mikrobiologie der Lebensmittel Band 1. Hamburg : Behr's Verlag, 2010, pp. 486-495. 
  • Sängerlaub, S. Active Packaging zum Schutz von Lebensmitteln. bdvi Seminar Verpackung. Nürnberg : Fraunhofer IVV, 2009. 
  • Ooraikul, B and Stiles, E.M. Introduction: A review of the development of modified atmosphere packaging. [book auth.] B Ooraikul. Modified Atmosphere Packaging of Food. London : Ellis Horwood Limited, 1991, pp. 1-13. 
  • Recent Application of Modified Atmosphere. Zhang et al. 31, s.l. : Taylor & Francis Group, 2015, Food Reviews International, pp. 172-193. 
  • Modified Atmosphere Packaging of foods Principles and Applications, Dong Sun Lee; Wiley, Sussex,  2021