CO2's critical role in extending shelf life

Dry ice has been used in the cold chain with great success but the other variations of carbon dioxide, liquid, and gas, also provide viable cold chain applications. Adam McCleery discovered.

The applications for Carbon Dioxide (CO2) across the food and beverage industry are numerous, particularly because the chemical compound can be used in its three forms, solid, gas, or liquid.

When it comes to the cold chain, the flexible nature of CO2 makes it an ideal application for storage and transportation.

Supagas, a supplier of LPG, Industrial, Medical, Specialty and Hospitality gases, supplies CO2 specific to the food and beverage industry for various uses.

David Petroff, Supagas’ National Industrial Bulk Manager, expressed the use of CO2 as a cooling tool, whether as dry ice or otherwise, was already successfully used within the food and beverage sector, particular in terms of food preservation.

The concept around the use of CO2 and dry ice for cold chain supply and storage is about extending shelf life, which in turn gives the product greater chance of sale before spoiling, mitigating the risks of recall and reducing the threat of food waste.

Food waste is of key focus and major issue in the food and beverage industry, on a global scale as it costs the economy billions of dollars a year, so a strong cold chain is a critical factor in helping to reduce those figures.

“For example, some of the cold chain uses of dry ice include meat processing manufacturers who take big meat carcasses and bone them,” said Petroff.

“When they move on to somewhere else that uses this meat, they cut the meat up and put it into containers and layer it with meat and snow. The CO2 snow comes from an on-site cryogenic liquid tank, that is usually outside the plant building that is piped into the boning rooms with equipment converting liquid CO2 into snow”, Petroff highlighted.

“It’s basically uncompressed dry ice and it provides affordable mobile refrigeration for their meat cuts, so nothing spoils during or waiting for transit.”

As another example, the use of CO2 in the cold chain is also a factor in huge food chains, such as the meat patties of many burger franchises, the CO2 is used help create the uniform meat patties which are well known throughout the fast-food industry.

It’s a big selling point for food chains to provide consistently uniform product no matter the location, this in turn aided by the temperature control of the mince, and it becomes easier to work with.

“The way that happens is they get their meat cuts and then mince and process the meat, using specialised mixing machines to form the meat patties,” said Petroff.

“If mince isn’t cold, then it sticks and is hard to keep it consistent, so we have CO2 on site that clients inject into the machinery to provide temperature control. This injection of CO2 in liquid form turns into dry ice snow when it is applied and cools down the mince. So, when the patties are formed the coldness helps them manipulate the size and shape of the minced meat.”

Once this step on the manufacturing process is complete, the patties need to be prepared and packaged for cold chain transport.

They are run through a large freezing tunnel conveyor, up to 25-foot in length, where liquid nitrogen is used to snap freeze the patties which is applied by spray nozzles.

“Then they are loaded immediately into sealed cartons before they are stacked in cold rooms,” said Petroff.

“Then the refrigerated semi-trailer takes them to where they are going.”

The recent growth in the ready meals market is another area of focus that highlights the key benefits to strengthening a cold chain from paddock to plate.

Despite the variety of ready meal products, such as pasta, fish, and beef, each with different ingredients, all still require the same level of care. This is to ensure it makes it to the point of sale in perfect condition and ready for the customer.

“All of them rely on being kept in a state of preservation so that nothing spoils,” said Petroff.

“When you go to the supermarket freezer you expect to pull out a ready meal in perfect condition. To provide the product in that state, it must be looked after from the time it is made to the time of distribution.

“Once you start the food production process on a cold chain, you can’t stop, you have to see it all the way through to the end.”

When a customer employs the use of CO2 from Supagas, a tank is installed on the premises and filled with CO2, which is then refilled whenever needed.

Another example of the use of Supagas applications across the food and beverage industry is in the wine sector where gases are used in every step of the process from picking, to crushing, and fermenting.

In being able to convert CO2 into dry ice snow, as well as the applications used as noted above, is possibly the most striking example of the flexibility of CO2 as a compound.

“One of the main benefits of dry ice, when used to apply as a cold agent, is that it is not being turned into water – it is turning into a gas, so it leaves no waste behind,” said Petroff.

Supagas’ dry ice is used with some big brands, popular for pre-packaged meal services.

“The use of Supagas dry ice and the main reason customers do use it, is because the dry ice gives superior longevity and cooling capacity compared to frozen gel packs. And nothing comes back,” expressed Petroff.

“However, in a box with frozen gel packs, the problem is the gel packs are still there when they’ve melted. So, it’s not quite as nice in terms of the environment.”

Dry ice turning to a gas instead of liquid once it deteriorates which is not the only feature of the product. It also has around double the refrigeration capacity of traditional water-ice and has a “one-way ability” with no mess as Petroff calls it.

Businesses also utilise dry ice in the rapid cooling of food and in the preservation process of the cold chain, such as in retail freezer tray meals which are heated before consuming.

“Meals are rapidly cooled using dry ice; which then goes into refrigeration. This locks in the flavour and the goodness of the food by making it frozen really fast,” Petroff said.

CO2 has proven to be a versatile application in the use of food production and cold chain supply, and Petroff hopes to see more within the industry looking into the advantages it creates in terms of shelf life and food preservation.

To find out more about Industrial Bulk Gases contact the Supagas Gas Professionals.