Which foods and beverages are suitable for MAP?
Read on to discover some of the most popular foodstuffs packaged in modified atmospheres.
Modified Atmosphere Packaging (MAP) is suitable and beneficial for a wide range of foods and beverages. Already a popular process, MAP is becoming increasingly common due to the rising popularity of convenience products and ready meals.
Coffee, as a dried product, is resistant to microbial spoilage so MAP is not required to inhibit microbial growth. However, coffee contains fatty acids which can oxidise, turning it rancid. For this reason, oxygen must be displaced from coffee packaging which is why a modified atmosphere of pure nitrogen is often used is coffee capsules and sachets.
One dairy product which typically benefits from MAP is cheese. Cheese is susceptible to microbial growth (such as mould) and to turning rancid, but these can both be prevented with MAP. Carbon dioxide is the gas typically used with cheese for this purpose but there is a particular risk of CO2 being absorbed by soft cheese which can lead to packaging collapse. Therefore, different concentrations of CO2 are used depending on the robustness of the cheese being packaged.
With other milk products such as yogurt and cream a lower CO2 concentration should also be used as these products can absorb too much CO2, causing them to become sour. To avoid this altogether, nitrogen can be used in packaging for yoghurts, mousses and powered milk, as well as soft, grated and sliced cheese.
Snacks such as nuts and crisps typically have a high fat content and this puts them at risk of being affected by oxidation, which makes them rancid and stale. To prolong their shelf life oxygen must be eliminated from their packaging. To achieve this crisps, nuts and similar snacks are typically packaged in food grade nitrogen, which not only prevents oxidation, but also protects the product from damage by providing an air cushion. A packet of crisps is a good example of this protective effect.
The shelf life of baked products such as bread and cake is predominantly affected by mould. Often these products are packaged with CO2 to displace oxygen and prevent microbial growth. However, CO2 is easily absorbed by the product which can lead to packaging collapse, so nitrogen is often also used as a supporting gas to prevent packaging collapse The mix commonly used is 50% nitrogen and 50% carbon dioxide but there is a movement towards using a greater quantity of nitrogen as this is more cost-effective but doesn’t compromise the benefits of MAP.
Sausage and meat products (especially raw meat) are extremely vulnerable to spoilage caused by microbial growth. This is because these products have high nutrient and moisture contents. To prevent microbial growth CO2 is used but in the case of red meat oxygen is also used to prevent the meat from losing its appealing red colour. With cooked meats and sausage style products sometimes a mix of CO2 and nitrogen is used where the percentage of nitrogen will usually be greater than the percentage of CO2.
After harvest, fruit and vegetables continue to breathe, so their packaging must allow for this by providing an oxygen content, albeit it a low one. Commonly fruits and vegetables are packaged in mix of CO2, nitrogen and oxygen which is referred to as EMA (Equilibrium Modified Atmosphere). EMA gas is adapted individually for its corresponding product to provide the ideal atmosphere for that product.
Gases, such as food grade nitrogen and argon, are used in the wine production process to protect product quality. Their main purpose is to eliminate oxygen, preventing oxidation from occurring and affecting the wine’s taste. Argon and nitrogen are somewhat interchangeable when it comes to wine making but argon is not as readily available or cost-effective as nitrogen, which can generated on demand. In the winemaking process nitrogen has a variety of uses as it can be used for nitrogen flushing, sparging and blanketing, all of which help keep oxygen out of the wine during its production.
Ready-made meals are more complex than other foods when it comes to MAP. This is because they contain a variety of different foods which all have varying shelf lives and vulnerabilities to spoilage. It is common for a mix of CO2 and nitrogen to be used in ready meal packaging and their concentrations will depend on what is being packagedFor example, if the food being packaged could absorb enough CO2 to risk packaging collapse, a higher concentration of nitrogen will be required. Typically, a 70%-30% mix of nitrogen to carbon dioxide is used.
Detailed above are some of the most common foodstuffs which benefit from Modified Atmosphere Packaging and the majority of them are packaged using nitrogen gas, either on it’s own or as part of a gas mix. If you are considering nitrogen for MAP or are already using nitrogen packaging and would like to control your costs, click here to discover our i-Flow nitrogen generator. i-Flow provides food grade nitrogen ideally suited to MAP.
MAP is often used with ready meals
Factors which impact the effectiveness of Modified Atmosphere Packaging for foodPosted in all news on November 13 2019
If you use or are considering using Modified Atmosphere Packaging (MAP) to prolong food shelf-life,…Read More
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