Gas provider helps businesses diversify during COVID-19

Change is something that can be embraced, or seen as an unnecessary disruption that can cause anxiety. But what happens if that disruption is unexpected and takes away, literally, your whole market share.

COVID-19 has had a negative impact on a lot of industries and businesses. And while food and beverage have generally come out of it okay from a consumer point of view with regard to supply and demand (pasta anybody?), there are certain sectors that have suffered considerably. Imagine you are a caterer who specialises in weddings, or a major supplier to airlines. One way to try and make up the deficit is to diversify.

And quite a few companies have, according to food-grade gas supplier Air Liquide’s Modified Atmosphere Packaging (MAP) specialist Remi Saget. Like a lot of companies hit by COVID-19, Air Liquide has seen a downturn in some of its areas of business, but there has also been interest in other aspects.

Some impacted food manufacturers have decided to expand offerings and started looking at other markets, whether it is online with home deliveries or via retailers. Supplying food products to such channels helps tremendously when shelf life is extended, which is possible using MAP. And in order for MAP to work, you need a good gas supply, which is where Air Liquide comes into its own.

Saget said there has been an increase in queries from SME manufacturers about how they can get longer shelf life for their food. Indeed, supermarket chains and independent grocers need products to stay on the shelf for longer than a day or two, often making it part of their requirements.

“We have had an upturn in requests,” said Saget. “We have seen more demand for food-grade gas, especially for ready meals. For some companies this is already their business, but many restaurant chains and catering companies had to change quickly to the same business model that would allow for home deliveries, selling at supermarkets, or selling online.”

In order for a company to be able to pack ready-to-eat meals, it needs to have a packaging machine that is capable of getting the meal prepared for being sold in store.

“It’s not a difficult transition to make if you have the correct packaging machine,” said Saget. “Obviously, you need to have one that has a gas flushing capability. You cannot gas flush manually.

“Packaging machines come in all sizes. Even your local butcher has a bench-top vacuum machines that could gas flush, or be retrofitted to do so.”

He said that gas is the last piece of the puzzle. Ultimately, manufacturers need to have the food right, then the packaging machine, the plastic tray and film, and then the gas. For ready meals, Air Liquide recommends a mixture called Aligal 15, which is made up of 50 per cent food-grade nitrogen and 50 per cent food-grade CO2. But this ratio may be adapted on a case-by-case basis.

“How it works is that the machine takes all the air out. It is the oxygen that will spoil the food eventually,” he said. “Then you add the gas. It takes a few seconds. The gas is food-grade, it is not chemical or anything like that. It’s considered a processing gas, so it is not an ingredient or a preservative and does not need to be on the label.”

Saget is confident that while some of these companies have had to look for new markets out of necessity, he doubts they’ll stop producing gas-flushed food products once the industry gets back to normal.

“It’s probably going to be the case for most companies that have gone into the ready meal business that they will stay in there once things have gone back to normal,” he said. “They have been doing it for a few months now and they realise that it is working well, and it would allow them to have an extra stream of revenue. People are used to buying online, so they can easily keep their online shop open and keep delivering to people.”

One such firm is catering company Harvest By Darren Taylor, which saw the bottom fall out of its business, with 100 per cent cancellations of weddings and other events it had been booked to supply food prior to COVID-19.

“They also operate a bakery and make great pies and croissants for cafes across NSW,” said Saget. “The sale of bakery products they did went down by 95 per cent. They had to rethink their business model.

“The good thing was for founder Darren Taylor, he could start pretty much right away thanks to a machine he purchased earlier.

“I helped him with the right gas mix according to his food. We did some tests together to make sure the gas was flowing okay. Now he is selling online and is also selling to independent supermarkets across NSW. He also sells to a big chain of butchers where his packed dishes are available in the open fridge next to the counter where you buy your meat. He is very happy.”

Taylor said he got an opportunity to get into the ready meals market in late 2019 and was planning on getting started halfway through 2020, but due to the effects of COVID-19, he decided to enter the market sooner.

The majority of outlets require prolonged shelf life to avoid dealing with products that are past their use-by date. This is especially true for ready meals, where they are packed in air, and they usually stay fresh for only a few days. A preservative-free conservation method like MAP helps.
“We got a packaging machine in Melbourne, and we looked at all the ways of extending the shelf life of the product and we decided to go with the MAP method,” said Taylor.

“We went with MAP because of the look of the product, it keeps the integrity of the product and it is very safe and reliable. After ordering the machine and getting it in, we did a whole lot of tests. We developed a product that we thought would suit that application.”

Taylor was very pleased with the service from Air Liquide in terms of getting it all set up.
“Remi and his team were amazing,” he said. “Remi was extraordinary. He came in at the very beginning and we got the machine working in a way we were happy with it. Remi helped us with our gas levels, our oxygen levels, etcetera. ”

The beauty to the system, according to Taylor, is that he cooks the food, trays it up straight away, puts it in the blaster until it comes down to 1˚C, and then packs it.

“It’s as good as you can get in terms of packaging. The film, the tray and the label – which is stuck on – are all microwave-oven proof. It has zero additives or preservatives,” he said. “By using MAP, you don’t have to put any chemicals in it.”

With the eyes on the future, Taylor and his food manufacturing business emerges from the COVID-19 crisis better positioned to face ever-changing market demands. The fact that he was able to swiftly adapt his operations is a reminder that tight partnerships with suppliers goes a long way when help is required to come out of a dark time, pandemic or not.

Why CO2 production is vital to food and beverage industry

Carbon Dioxide (CO2) gets a bad rap in the larger scheme of things. It is the bogeyman of the climate change world. Yet, without it, the way people consume food and beverages – even how food is packaged – would not be the same.

Air Liquide is an industrial gas-producing specialist, and one of the key ingredients it supplies to the food and beverage industry is carbon dioxide, in all its forms.

Frank De Pasquale is the business unit manager for CO2 and Hydrogen (H2) for the company in Australia. He has been with Air Liquide for 15 years and has been in charge of its CO2 production for the past 12 months and is well versed in its place within the sphere of the food and beverage landscape.

There is an increasing amount of CO2 in the atmosphere, but as of today this is generally not economic to recover, so industrial gas companies need to identify a suitable CO2 emission source and give it a second life by purifying it to food or industrial grade for commercial use.

“Unlike some of our competitors, we never produce additional CO2 from burning natural gas; we recycle and purify existing CO2 emissions from others. We are proud of this commitment which is part of our Corporate Climate Objectives.”

All CO2 emissions are a mixture of CO2 and various impurities, but it is what makes up those impurities that matter when it comes to commercialising the product.

“It could be 99.99 per cent CO2, but has 20 parts per billion of benzene in it, which at parts per billion level is not very much,” said De Pasquale. “However, such a little amount of this kind of impurity means that the CO2 is not suitable for the food industry.”

And how does Air Liquide source its CO2? There are several avenues it utilises. Currently it sources feedstock CO2 from seven different industrial processes, all of which emit CO2 as they make their products – three produce ammonia, one is a power station, one is a steam boiler (both are combustion flue gas sources), while there is one that produces ethylene oxide and another is from a natural gas producer. Each feedstock source has its own set of impurities that has to be dealt with, and then the gas has to be collected so it can be made commercially viable. Take ethylene oxide as example.

“We can get CO2 from a chemical process, such as ethylene oxide production,” said De Pasquale. “When ethylene is reacted with oxygen, it makes ethylene oxide and CO2. The process then requires CO2 to be removed, which we can capture, then purify for the food industry.

“However ammonia plants are definitely the best feedstock source; CO2 produced this way has the least amount of impurities in it.”

The reason for this, said De Pasquale, is that to make ammonia you need to have a reaction between hydrogen and nitrogen which results in a relatively clean stream of CO2 containing less impurities than other emission sources.

“As you go from ammonia to ethylene oxide to natural gas processing to flue gas – you get different levels of purity for CO2 and different impurities that you will need to deal with,” he said.

The cost of production varies greatly because it’s based on the processes used within the different disciplines to ensure food and beverage grade quality. In most processes, there are a few steps.

“Typically, there is some level of compression – there is also, as a general rule, a degree of filtration and drying, followed by liquefaction and distillation,  to purify the feedstock to the required quality,” said De Pasquale. “The process produces CO2 in liquid form, which is approximately -22˚C and 20 bar pressure. Not only does producing liquid aid in the purification process, it also allows us to transport it more economically than you would if it was in a gaseous form.”

Once it is trucked to a customer’s site it is loaded into a bulk tank, and the customer typically uses it in a gaseous form, which is made possible using a simple air-heat exchange system to vaporise the liquid CO2.

Dry ice is another specialty of Air Liquide’s, which is the solid form of CO2 that typically sits around -79˚C. One of the special properties of dry ice is that it sublimes from its solid form directly to its gaseous form. This is important in the food and beverage industry, when dry ice melts into a gas it does not leave a residual on the food.

“Airlines use dry ice to keep your drinks cool and to transport fresh produce from Australia to export markets. The Red Cross use it when they transport blood and other human specimens such as plasmas,” said De Pasquale. “We have a large number of meat and poultry processors that have bulk liquid storage vessels on site. The liquid CO2 is piped to their processing equipment where it converts to dry ice, which chills the meat to prevent biological or bacteriological development and facilitates product forming into beef patties or chicken nuggets.”

CO2 is a product with highly sought after properties. This explains why it is used in the food and beverage industries in its liquid, solid and gaseous forms across a range of applications.

Quality and the supply of a safe product to these industries is paramount, so how do they carry out quality control?

“We continually test the quality of our CO2 in real time,” said De Pasquale. “We have a detailed and audited food safety management system known as FSSC 22000, which is a systematic approach to controlling food safety hazards within our production and distribution activities. This ensures that we provide a safe product to the food and beverage industries. It covers everything from plant design right through to pest control and waste disposal.”

According to De Pasquale, from the process aspects, it covers everything from the feedstock CO2 stream and process conditions,  through to final product testing and distribution to the market. It is not just testing the final product, it’s about assessing, monitoring and controlling all risks, all of the time.

“We produce and test CO2 in batches; we test it online and send samples to external labs; and we also monitor process conditions,” he said. “We know if the process conditions vary, then something could be impacting on our product quality. These are real-time variables, and the last part of the system involves testing of the final product.

“If we don’t have these systems in place, by the time the final  product is made, it is typically too late. We test the final product to confirm that everything else in our system is working. It’s not a catch-all last measure – the important part is making sure the processes are in place from the beginning.”

Another major and ever-growing market for CO2 is water and waste water treatment where it is used for pH control and remineralisation. Every Australian capital city’s desalination plant uses CO2. The plant is a critical water supply source, especially as drought takes hold.

“CO2 is also one of the most humane way to process animals like chickens and pigs,” said De Pasquale. “It is used in MAP (modified atmosphere packaging) as a bacteriostatic agent, thus extending the shelf life of chilled and ambient products. Australian supermarket shelves are packed with trays or packs of MAP products ranging from meat and poultry to dairy products such as cheese and milk powder to pasta and bakery products. CO2 is used with all these products and is a key component of the system that extends shelf life.

“Another application that I should mention is glasshouse enrichment. You can grow crops in a field, but to increase the yield of your crop and also the growing season, you grow them in a glasshouse where you control the temperature and you can control the CO2. The glass house operates at a slightly elevated CO2 level, which improves crop production.”

De Pasquale is also keen to point out that he doesn’t see the production of CO2 – in the context as to why Air Liquide makes it – as an industrial process.

“The way that we run our CO2 production plants is driven by the requirements of FSSC 22000, which is strictly a food and beverage industry standard,” he said. “Our CO2 plants have this certification because the food and beverage industry is our major market and CO2 is used by this market as an ingredient or as a processing aid. So these production plants are not industrial production plants, they are food ingredient production plants.”

And when it comes to the general public, the bottom line as far as De Pasquale is concerned on the merits of CO2 in the food industry?

“Take soft drinks, sparkling water – everybody wants drinks with bubbles in it,” he said. “And what about beer and soft drinks on tap? Pubs and bars use CO2 to dispense these beverages. At the end of the day, no CO2, no beer, no soft drinks.”

Speed of the essence when it comes to cryogenic temperature control

In different parts of the food industry, various techniques to give foodstuffs the required temperature during or after mixing have been developed. These include adding chilled water, brine, or water ice to the product, using over-chilled or frozen ingredients, or most commonly using mechanically refrigerated mixing equipment.

Spraying or injecting a cryogenic fluid onto the product in the mixer while it is being mixed is also an efficient and safe ways of chilling. Industrial gas company Air Liquide specialises in the latter – utilising liquid nitrogen or liquid carbon dioxide to chill produce quickly and effectively. There are several benefits to using cryogenic freezing, according to Stephen Crawford, who is an Air Liquide senior engineer and expert in food cryogenics.

“It’s not hard to implement,” said Crawford. “Either liquid nitrogen or liquid carbon dioxide can be sprayed onto merchandise being chilled either from the top or the bottom. Both methods are used in industry and can be installed on existing equipment.

“Usually they are injected into some sort of mixer – for example, protein mixing, such as beef or chicken mixing, which is being made into patties or nuggets. It’s cheaper to install top mixing than it is bottom mixing, but the bottom injection method is more efficient.
“We use this type of injection to maintaian temperature. As food is mixed, you get friction between the product and the blades so heat is generated. You need to maintain temperature below 4˚C so you don’t get bacterial growth.”

Another benefit is that the gases have direct contact with the food. If an ammonia chiller is being used in a mixer, users might be able to cool down the walls of the mixer but there is no direct heat transfer that is possible when liquid nitrogen is injected into the mixer itself.
“From a heat transfer point of view it’s much more efficient,” said Crawford.

As mentioned, speed can be a key. Crawford cites the example of one of Air Liquide’s clients that specialises in producing goat cheese, a produce that is temperature sensitive.

“When the milk comes out the goat, it’s at room temperature or above. The longer it takes to get down to 4˚C, the shorter the shelf life will be,” he said. “The company puts it into a mixer and injects liquid nitrogen at -196°C through a cryo-injector. They get liquid nitrogen coming up, which rapidly cools the milk. As a comparison, mechanical chillers can only reach a temperature of -35°C with ammonia refrigerant.

“What would have taken them hours if you had put buckets of it in a mechanical chiller happens in just a few minutes in the mixer. You have blades inside stirring it. You don’t end up freezing one portion and having another portion still warm. They are constantly stirring it while injecting liquid nitrogen. It brings down the temperature of the whole product much quicker.”

Some of the mainstays of cryogenic chilling are chicken nuggets and meat patties, which are popular with those who process fast-food items. However, cryogenic chilling can also be used for dough mixing.

Most large flour mills have the flour stored in big silos outside. Industrial bakers blow it around pneumatically to get it into the mixer. It is the most efficient way for them to move the flour. The flour then comes into its mixture where it is combined with water and other ingredients. It’s mixed mechanically. But the temperature of the product in pastry has an impact on the texture and the final outcome, according to Crawford.

“If you’re trying to make a product that has a certain amount of ingredients and you mix them all together at 15˚C instead of 20˚C, the texture of the final product will be quite different even though the ingredients are the same,” said Crawford. “The bakeries find – especially if they have days like in the middle of summer where it is 35˚C – when you introduce that into the dough, the dough is far too hot and melts the butter. If you can inject a small amount of cryogen, then, depending on the temperature, it can make all the difference. If it is 20˚C you know to inject nitrogen or carbon dioxide for 10 or so seconds, or if it’s 35˚C you might have to inject for 40 seconds. During the process, it brings the dough to a consistent mix. This means there will be the right chemical reactions with the yeast. Over the years, Air Liquide has acquired a deep knowledge of process parameters through hundreds of references in cryogenic chilling worldwide and knows how to implement the right recipe to reach desired outcomes.”

Crawford also talks of the safety aspects the cryogenic chilling can offer. Most large commercial chillers have ammonia in them, which means they have a refrigeration cycle, so they’ll have a pump that is compressing the ammonia. Like a fridge at home, the wires on the back get hot. There’s a heat pump that takes the heat energy from inside the box and puts it into the grill at the back. An industrial refrigerator works the same way but ends up with large cooling towers to get rid of all the excessive heat.

“This means factories have these ammonia lines running through their plants which you wouldn’t want to spring a leak,” said Crawford. “However, with cryogenics, if you have a minor leak of nitrogen, it must be repaired, but it is not an immediate hazard. Eighty per cent of the air we breathe is nitrogen. Ammonia is a corrosive and toxic chemical and customers require ammonia sensors around the place. Often they spend a lot of money maintaining it, and then you have the cooling towers and all the other issues with the cooling water side of it.”

Some synergies are also possible with other processes down the chain, such as food freezing and modified atmosphere packaging that also use nitrogen, carbon dioxide and mixtures thereof, which further reduce the cost of operations compared to mechanical chilling.

“Another advantage is that it is very reliable because there are very few moving parts when working with cryogenic chilling,” said Crawford. “The injectors can be retrofitted on customer’s existing mixers.

“With only a valve to open and close, there is no compressor that needs to be maintained like on a mechanical system. The servicing requirements just aren’t there. The cooling equipment we have is better. There is nothing hard about what we are doing. It’s an easy method for people to learn to do. We can even maintain the equipment for our customers.”

Putting wine on ice – gas’s role in winemaking

The main hero and villain in the wine-making process is oxygen. Generally, the use of various gases in wine production is necessary to negate the destructive nature of oxygen. Gavin Hall, Air Liquide’s sales representative for food and wine in South Australia, said this is where his company’s expertise comes to the fore.

“The management of oxygen in all the wine making processes is paramount to the industry,” he said. “This is because oxygen is what defines the quality of the wine and its organoleptic properties.”

Throughout the production process, the wine itself is subject to various oxidation processes. A certain degree of oxidation is necessary, but direct contact with oxygen has a detrimental effect on the quality of the final product. It is possible to control how oxygen interacts with the wine by using a variety of different gases. All wineries have to use gases to control the intake of oxygen. These gases include nitrogen, carbon dioxide (CO2) argon and sulphur dioxide.

Hall said there are eight stages in which gases are involved in the processing of wine.

Stage 1
The first stage is during the harvesting and transport of grapes from the field to vineyard/winery. In this stage, the crushed grapes start getting in contact with oxygen in the air. It is important to negate that contact but it is difficult to achieve, which is why there is a need to lower the temperature in order to slow down the oxidation process, said Hall.
“As soon as the grape juice comes in contact with oxygen, the fermentation starts, as does the oxidation process. What you want to do is lower the temperature of the grapes,” said Hall. “Because the lower the temperature the slower the oxidation process.”

In this stage CO2 is mainly used in the form of dry ice. “In Australia, compared to Europe, most wineries don’t use this cooling process due to the initial phase, they usually try to process the grapes as soon as possible,” said Hall.

Stage 2
Once the grapes are crushed, the pressing process allows for the production of clarified juice, which is transferred to different tanks to ferment. Winemakers need to displace the air from empty vessels into empty pipes before transferring the wine to ensure there is no residual oxygen. This is called purging.

“When you need to purge the tank,” said Hall, “you utilise an inert gas to flush out the remaining liquid or air under a certain pressure.”

Nitrogen is mainly used in this stage. The process of purging is done by building slight overpressure with nitrogen in the tank, or in the pipeline. The wine maker is stopping the oxygen from coming in contact with the grape juice that has just been crushed out of the grapes.

“You are basically displacing the oxygen from the air that has already come in contact with the juice,” said Hall. “You’re using nitrogen under pressure to purge and transfer juice within the tanks.”

Stage 3
Then comes what is called tank inerting. This encompasses blanketing the surface of the wine tank after the juice has been collected.

“You are blanketing the surface with a protective layer of gas during the storage, or when you are emptying the tank,” said Hall. “By doing this to the tank, you prevent oxidation.”
The gas used can be nitrogen, CO2, or a mixture of the two. Vintners can also use argon, but that can be a little more expensive. In Australia, tank inerting is very important, and it is common to do it with dry ice.

“Using dry ice is preferred by winemakers because it’s practical, and they can actually see it and it’s a bit cheaper,” said Hall.

“You scoop it into the wine tank. Because CO2 is heavier than air, it creates a layer at the bottom of the tank blanketing the wine, thus preventing oxygen contact.”

Stage 4
Winemakers are constantly measuring the dissolved oxygen in the wine. Depending on the wine being made, some vintners do what is called deoxygenation which consists of stripping out the excess oxygen that is dissolved in the wine.
“For this process you would use nitrogen,” said Hall. “By injecting nitrogen in the form of tiny bubbles into the wine, you are forcing the dissolved oxygen into the gas phase, and then the gas is vented out of the tank.”

Depending on the type of wine that is made, vintners need a certain amount of dissolved oxygen. It is one of the key criteria to produce quality wine.

Step 5
The next step, also using nitrogen, consists of mixing or homogenising. Nitrogen is bubbled at the bottom of the tank. When the bubbles raise to the surface, they are mixing the various products together.

“That is why it is called mixing,” said Hall. “This comes into effect when wine makers need to homogenise the wine they are making. It avoids oxygen pick up.”

Bubbling nitrogen is also used during must lifting process but this time during the fermentation. This process brings up all the dense solids that have accumulated at the bottom of the tank.

The benefit of must lifting using gas is that it saves times.

Step 6
Bottle inerting is the next step. This means that when the wine is being bottled, gas is already being used. Like most of the other steps, it is all about minimising the amount of oxygen in the wine.

For this step, it is possible to use CO2 or nitrogen, or a mixture of both. Every bottling line in a winery has filling machines equipped with gas injection. The decision on what type of gas is to be used depends on the type of wine that is being made.

“Most winemakers use nitrogen to apply counter pressure in the bottles to purge the oxygen before filling them with wine,” said Hall. “The oxygen is eliminated inside the bottle, then you fill them with wine.”

The second step in the bottling line is the headspace of the bottle. After the bottle has been filled, there is a gas injection point, which is filling up the headspace of the bottle after the wine has been put into the bottle.

Step 7
Depending on the wine and oxygen level of the tank, some winemakers might use oxygen in the different steps of the winemaking process. This is called oxygen enrichment.
“The winemaker reintroduces oxygen to help maintain the yeast activity in the wine to minimise the risk of stuck fermentation and the production of undesirable sulphides,” said Hall. “Oxygen is not always bad in the winemaking process. This is a controlled situation. You’re not putting wine in contact with air, you’re injecting oxygen in micro doses. The yeast works on oxygen. The simple process of wine making is that you have the sugars in the grapes and then the sugars become alcohol, or ethanol in this case. This process is using oxygen to transform the sugars into ethanol. What you don’t want to do, is put in too much oxygen. Then the alcohol becomes oxidised. You need to control the amount of oxygen you put in the wine.”

Step 8
In the case of still wines, the CO2 level is usually adjusted before bottling, according to Hall. Winemakers can measure the level of CO2 that is dissolved in the wine and bubble nitrogen if it is too high or dissolve CO2 if it is too low. In the case of sparkling, this adjustment is brought about to carbonisation of the wine.

“Now you have the wine that is ready,” said Hall. “Oxygen is the one that creates the magic. It is the management of oxygen that is important and you need it to be controlled at all steps of the process. It is a critical thing for winemakers. An excess of oxygen is bad. You want to avoid direct contact with air.”

If winemakers are thinking of using the gas suite offered by Air Liquide, they come in three different modalities.

For small wineries they come in gas cylinders. For medium- to large-sized installations, the gases are supplied in bulk via big tanks. For big wineries, Air Liquide can install and operate a nitrogen generator onsite.

Cryogenics offer alternative freezing solutions

When thinking of cryogenics, most people think of the science fiction fantasy whereby billionaires freeze their decaying bodies in liquid nitrogen in the hope that technology will catch up and allow them to live forever.

In real life, cryogenics has many, less dramatic purposes, albeit important ones – including the freezing of foodstuffs.

There are two standard methods of freezing foods at an industrial scale. One is mechanical, and the other is the aforementioned cryogenics.

The mechanical method involves using a chemical refrigerant such as CFCs or ammonia, which is used in a closed cycle. The system moves large volumes of air to freeze the product. It cools the air like a refrigerator, but, is of an industrial size with a bit more grunt in its engine.

A cryogenic system is different. It uses liquid nitrogen or liquid carbon dioxide to freeze the product. It has direct contact with the product either as droplets of liquid nitrogen, or solid particles of carbon dioxide (dry ice)because carbon dioxide cannot exist as a liquid at atmospheric pressure.

Air Liquide is one company that specialises in cryogenic freezing and is at the forefront of a technology that has been around for more than 50 years.

The company’s senior international expert in food processing, Aron Segal, knows that cryogenics is a niche market, but an important one. There are benefits and issues with both mechanical and cryogenic freezing. However, cryogenics is not utilised as much as it should be, especially for those people that don’t have a massive amount of money to invest in capital.

“When it comes to mechanical freezing, the operating costs are strictly dependant on the price of electricity,” said Segal. “But, you have a high capital investment for the equipment. There is little operation flexibility with the mechanical freezing system because you basically set your set points in the freezer and so you have very little movement of that temperature.”

It also takes a longer time to install a mechanical freezer system than a cryogenic one. There is a lot of maintenance required to keep  the mechanical system in good working order.

“Against that, you have cryogenic freezing, which requires a lower initial investment because the equipment is smaller, it operates colder and can be rented,” said Segal. “There’s very low maintenance and no compressors. There is just injecting a fluid into a freezer and then exhausting the gas.”

Cryogenics is also very fast freezing because products are frozen at a set point, such as -60, -80, -100 or -120˚C. It is rare for a mechanical freezer to operate below -40. And because cryogenic freezing is faster, it requires far less floor space because you are moving product through quicker. Then there is the science behind this type of freezing system.

“You get quality product because the faster you freeze something the smaller the ice crystal size,” said Segal. “The larger the crystal size, the more likely the product is going to thaw out not looking exactly like it did when you froze it, which when it comes to vegetables and fruits, can be a problem.”

Then there is moisture loss, which can be a big issue when manufacturers are selling product by weight and they lose four or five percent of that product’s weight in the freezing process. It’s a big cost to the bottom line. Because cryogenics is faster, there is less loss.
Segal said that cryogenics are also ideal for those that are just starting out a business mainly because of the aforementioned lower capital outlay as well as a lack of space. Not only that, but if the business is volatile, a company could be left to the whims of its clients’ fickleness.

“If you have invested in a mechanical system and you lose an important customer in two or three years, you’re stuck with that plant,” he said. “If you opt for cryogenics, with the correctly sized cryogenics freezer, it takes up far less floor space and you can install it overnight. You can press the button the next day. And if you lose the market, you’re not stuck with high-end capital equipment.”

Segal also said that cryogenics is capable of targeting specific aspects of a product, which again, is another feature it has over its main rival in the space.

“We’ve developed a range of equipment to do other things, not just simply freezing produce. We can crust freeze and crust harden,” he said. “Let’s say your end product is sliced ham. You have these large portions you want hardened a bit to make it easier to slice. With cryogenics you can get a firm outer surface that you don’t get with mechanical freezing because it will take a long time. Therefore, you’ll get more efficient slicing and far
less wastage. The slices can fall nicely on the conveyor where they can go into a qualified atmosphere packaging system.

“Another example is if you’ve got small particulate products like pizza toppings. To freeze them mechanically would be difficult. You’d probably have to do it in bags because you probably wouldn’t like it on a conveyor belt. Cryogenics has systems that can handle particulates so they don’t come out in a frozen clump. They come out free flowing.”

Segal gives another example of where cryogenic freezing would be ideal – desserts. A manufacturer can harden the main part of the product in the cryogenic tunnel – not fully freeze it, but partially freeze it. Then they can put a topping on it and put it through again and freeze the topping without intermingling with the lower component. This is especially important when different components of a product have different freezing points, or react in different ways to certain temperatures. Segal said that it is part of Air Liquide’s brief to work with clients on how cryogenic freezing can help them make sure their business reaches its potential while guaranteeing safe operations.

“Niche products are where we find our current market,” he said. “When people are trying to create these products, it is cryogenics that helps them. It’s not just about putting products in and freezing them, there is the value-added aspect. When we identify enquiries, we have to understand exactly what our client is expecting from the freezing process. We know very quickly whether cryogenics is going to be a process that supports their cost structure, and how suitable it is for their business or not.”

How to make food last longer on the shelf

Choosing the right packaging for your food or beverage can lead to the success or failure of a brand. But, as well as a good logo and pretty colours, your packaging needs to be able to sustain its contents. And the longer shelf life it has, the better for the producer. One way to extend the life of products is to use Modified Atmosphere Packaging (MAP) technology, which was created in the 80s and has been widely used since in pre-packaged foodstuff and prepared food and is championed by industrial gas specialist, Air Liquide.

The technique consists of replacing the air in the headspace of a package with a specific gas mixture. It is used to extend product shelf life and to provide an attractive presentation. This way, the natural deterioration of the product is slowed down and the initial fresh state of perishable products may be prolonged. It is commonly said that the shelf life extension with MAP is up to four times longer compared to a product packaged in air.

MAP helps preserve the freshness, colour, flavour and nutritional attributes of food products with an all-natural solution. This is because MAP can extend a product’s shelf life by slowing down microbial, enzymatic and physical deterioration. It also eliminates the need for chemical preservatives, provides mechanical protection for fragile products, and can optimise inventory levels. Side effects of using MAP technology is that its allows users to enlarge distribution networks to new geographies, reduces the amount of returns and food waste, and can provide an attractive package presentation for retail displays.

It is advisable to be careful, because there can be pitfalls. Temperature control, hygiene, and good sanitation practices still need to be followed during the manufacturing process. For refrigerated products, it is essential that the food product is in good condition with a low initial microbial load prior to MAP, otherwise the gases will not be able to extend the shelf life of the product. It is also important to know that refrigerated products must be stored at refrigerated temperatures, regardless of how they are packaged. If the storage temperature is higher than the recommendation, then the shelf life will also be shorter.

MAP technology also addresses all retail packaged food segments – both chilled and ambient. It is dedicated to the packaging step of the food value chain. It follows the processing or preparation steps and precedes storage and transportation ones. MAP could fit to bulk (big bags, cardboard) and portion units packaging (trays, bags).

MAP is used for maintaining the organoleptic qualities of food products for a longer period of time in most food processing markets whenever there is a risk of degradation if stored under air, such as:

• Meat and poultry customers – by far the largest users worldwide for fresh cuts and minced meat or processed products.
• Ready meals (pizzas, quiches, cooked meals, sandwiches).
• Dairy (milk powder, portioned/sliced/grated cheese products).
• Bakery products (bread, pastries, cookies, fresh pasta).
• Dry products (nuts, coffee, instant mashed potatoes).
• Fresh fruits & vegetables (lettuce leaves, grated carrot, fruit salads).
• Seafood (fish fillets and whole fish, processed seafood products).

Food Safety with MAP
Food safety is a public health priority that is presenting new challenges due to the increasing trends in global food production, processing and distribution. Consumers are regarding foodborne disease outbreaks with increasing concern.

Gases used in MAP are considered as food additives in Australia and as such must follow legislation applying to food additives including purity criteria.

Food MAP gases status depends on the local regulation concerning food additives enforced in each country, but must always be compliant to local food grade specifications and manufacturing procedures. Air Liquide guarantees that its ALIGAL range of gas products that are used in MAP complies with the Australian Food Standards Code.

The ALIGAL brand follows a Food Safety Management System (FSMS) based upon the requirements from FSSC 22000 (ISO 22000 + ISO TS 22002-1). Such a system provides evidence that Air Liquide is committed to:

• HACCP- (Hazard Analysis and Critical Control Points) and HARPC-based (Hazard Analysis and Risk-Based Preventive Controls) systems for carbon dioxide.
• Monitor O-PRPs (Operational Prerequisite Program) and CCPs (Critical Control Points) and record them.
• Implement, maintain and periodically test traceability.
• Use cylinders with specific labelling and special valves to avoid contamination.
• Manage non-conformities/deviations.
• Train people and ensure that personnel applies procedures.
What Gases Are Used in MAP?

The “atmosphere” is the gas surrounding the product. It can be active or inert. This gaseous atmosphere can be made of a single gas component (N2, CO2, O2 or Ar) or a mixture of these gases. The atmosphere can change over time if the film is not impermeable.

The mixture of gases in the package depends on the type of product, the packaging materials, the storage temperature, and the objectives sought by the food manufacturer. There are multiple gases and mixtures and the choice of the suitable one is not always straightforward. As an example, cheese would require different gas mixtures whether it is grated, sliced or in blocks.

A balance must be found between the shelf life requirements, the characteristics of the food product, and the CO2 levels in the gas mixture. It is advisable to run some MAP trials with different gas mixtures and the product, in parallel with quality and microbial analyses, in order to determine the best combination.

Carbon dioxide (CO2)) limits the growth of bacteria and slows down the development of mould, however a minimum concentration of 20 per cent in the gas mixture is required. Users must keep in mind that it is soluble in water and fats, which means that, in some cases, it can lead to package collapse and should be balanced with nitrogen. CO2 also reacts with water to produce a weak acid (carbonic acid) that could cause a flavour change in some products like tomato-based or mayonnaise-based products. When it comes to fresh fruits and vegetables, too much CO2 in the gas mixture can lead to premature spoilage since higher levels of the gas can affect the cellular structure of the product.

Nitrogen (N2) is an inert gas that is used to displace oxygen inside the package headspace in order to prevent oxidative reactions. It helps limit the growth of aerobic bacteria and is also used to provide mechanical protection for fragile products or to prevent package collapse because it has low solubility in water and fats.

Argon (Ar) has similar benefits to nitrogen as it is also inert, but it is twice as soluble as nitrogen in water. It can slow down the respiration rate of fresh vegetables better than nitrogen, thereby further increasing their shelf life.

Oxygen (O2) is usually the cause of microbial spoilage and oxidation but, in some cases, its presence is required. It is ideal for maintaining the bright colour of red meat. However, it can also reduce the shelf life, so it must be used in combination with CO2. It is essential for respiration of fresh fruits and vegetables to prevent premature spoilage or for blue cheese and mouldy rind cheese products (such as brie), to preserve the mould on the surface of the product. It can be used to prevent anaerobic conditions in produce such as fish, under which pathogenic bacteria like clostridium botulinum can grow.

Compared to air-wrapped or air-sealed packaged food product, on paper the MAP solution appears sometimes slightly more costly, mainly due to higher cost of the packaging materials. There are also indirect costs – packaging line productivity is lower (due to the fact that vacuum/gas injection sequence leads to a reduction in the number of cycles/min or packages/hour). Compared to vacuum packaging, the extra-cost of the gas is negligible; an indirect cost could be due to gas injection time (one to three additional seconds per cycle) therefore reducing packaging line productivity.

However, the benefits of MAP usually exceed its costs. The extended shelf life could be multiplied up to four times, allowing a reduction in logistics costs (storage and deliveries), production costs (optimisation of production schedules and series), and decreasing product waste.

Air Liquide can provide tailored solutions for food processors of all sizes. The company has the technical expertise to recommend the right gas solution adapted to each customer, whether it be packaging technology, packaging material, production capacity, size and shape of the product, desired product’s appearance, expected shelf life and logistics constraints.

The company can also propose multiple supply modes. Pure gases and mixtures can be supplied in cylinders and cylinder packs for small to medium food-processing lines. For larger food processing plants, Air Liquide supplies pure gases in cryogenic bulk vessels of different sizes along with on-site mixing systems when mixtures are needed.

Air Liquide also supplies customer support with its ALIGAL products. Based on its knowledge of the gas interactions with food products, the company provides solutions along with after-sales services. It has a dedicated worldwide network of international and local food and beverage experts to answer any questions related to MAP technology. It is easy for companies to access to Air Liquide expertise and resources to help companies optimise their process and operational costs.

They also offer training on safe handling of industrial gases and supply services for peace of mind that include the FLOSAFE gas reticulation system, bulk telemetry, rental of gas mixing stations, as well as maintenance and repair services. Finally, there are process services that include trials, product package atmosphere analysis and audits of packaging installations.

Air Liquide also provides gas solutions to many other industries, notably in water treatment, lab analysis, metal fabrication and healthcare.