Gases are rarely found among everyday goods, but what we buy in the supermarket often has something to do with them. Many products would not even exist in their usual form without them.
The only gas you can buy in a normal supermarket is butane for filling lighters. So, when you enter such a temple of consumerism you probably don't think of gases, but of things like tomatoes, liverwurst and dish soap. Without gases, however, many goods on the shelves would not look, smell and taste the way they do, and some would not be there at all. We went to the supermarket in search of traces of the volatile substances that are omnipresent in everyday life - and found many of them!
Shielding gases for trolley wire
The first trace can be found in front of the entrance where you grab your shopping cart. Several gases have done their work before the iron has been melted, drawn into steel wire, shaped and welded together into a practical shopping aid.
Oxygen was probably blown into the blast furnace to optimize heat generation, argon was used to "refresh" the molten steel and improve the quality of the steel. While this is formed into wire in the rolling mill, nitrogen prevents oxidation in the heating furnace. Last but not least, shielding gas mixtures are indispensable when robots weld the wires together to form shopping carts.
CO₂ fertilization and modified atmosphere packaging
Shopping starts at the fruit and vegetable stall. The tomatoes from the greenhouse may have been "fertilized" with carbon dioxide. The greenhouse air is enriched with the gas, which promotes growth and enables higher yields. The bag of pre-cut lettuce most likely contains a mixture of nitrogen, oxygen and carbon dioxide, which prevents brown edges and ensures that the greens stay crisp for longer.
Freeze-drying and high-pressure extraction
Pre-cut salad saves time, as does quickly brewed instant coffee. If it is to taste good, it should be freeze-dried: coffee extract boiled at 200 degrees Celsius and high pressure is foamed with air or CO₂ and then deep-frozen. Liquid nitrogen brings the cold into the cooling circuit. It also cools the ice condenser, which removes the water that has solidified into ice from the extract in the vacuum dryer. The gas can be used to lower the temperature to minus 100 degrees Celsius. This means that the drying process takes very little time and the aromatic substances are preserved.
When decaffeinating coffee, high-pressure extraction is used to remove only the stimulant and also preserve the aromas. Messer develops and optimizes the systems to suit the respective application.
Gas cooling in the mixer
The right mix: the range on offer at the sausage counter would look and taste very different without gases. When mixing minced meat, liquid nitrogen or carbon dioxide is introduced into the mixer as a cooling medium, for example with the Variomix process from Messer. The cryogenic gas extracts the heat generated during mixing. The low temperatures that are important for shelf life are maintained throughout the mixing process.
The same principle is also used to cool kneading machines in the production of baked goods. The Variomix process is also used in the production of powdered foods such as packet soups or instant products. When encapsulating powders, it ensures that the ingredients remain granular and free-flowing.
Fast freezing without loss of quality
What lies on the ice at the fish counter has already been through the cold chain. In addition to fresh fish, you can choose from a wide selection of frozen options that are almost as good as freshly caught fish. This is made possible by a modern freezing process using cryogenic gases.
When it comes to deep freezing, the speed of cooling is important. If it is too slow, large ice crystals form in the frozen food, which damage the cells and lead to the loss of vitamins, nutrients and flavor. In cryogenic tunnel freezers, food is, therefore, frozen with liquid nitrogen or carbon dioxide within a very short time. This process not only preserves quality but also helps to protect fish stocks. Closed seasons can be observed, and consumers can still enjoy their favorite fish all year round.
Flavors and fragrances
The fish is served with white wine whose fermentation temperature has been lowered with dry ice. This preserves the fruity aromas of the grape. As the fine wines mature an inert gas forces the air out of the tank and prevents oxidation. However, there is hardly a product on the other drinks shelves that has not had at least one gas involved in its preparation or bottling.
This starts with the carbon dioxide that makes lemonade fizzy and continues with the drop of nitrogen in the headspace of a fruit juice bottle. In addition to protecting against oxidation, the gas provides the pressure that stabilizes the thin-walled PET container. In the case of detergents and cosmetics gases were involved in many steps in the creation of most products.
Among other things, they help to extract natural fragrances intact from the raw materials. At a certain ratio of pressure and temperature carbon dioxide enters the supercritical state - an intermediate state between liquid and gaseous. This gives it enormous solubility and allows it to extract essential oils, for example, from plants both gently and efficiently. It is only during the final extraction at the supermarket - the wallet from your pocket - that you can actually manage without any gases at all.
For more than 125 years, Messer, the today’s world's largest privately owned company for industrial gases, medical gases, specialty gases, and gases for electronics, committed to its guiding principles of safety, focus on customers and employees, responsibility for our society, sustainability, trust, and respect. Messer's Gases for Life and patented gas applications are essential for environmental protection, climate protection, decarbonization, and innovation.
