Inert gas technology prevents oxidation

Gas company Air Liquide reports that new inert gas technology which prevents the oxidation of wine, and thereby maintains the qua- lity and character, has been introduced to the wine industry.

Air Liquide food and beverage market manager Lizbe Sorore explains that, by using the innovative Cryogen Injector, which uses liquid nitrogen dispensing technology either as a prepurge in empty bottles or as a post-purge in filled bottles, winemakers can achieve a significant and consistent reduction in dissolved oxygen (DO) levels of bottled wines.

“The primary aim of the winemaker during the bottling process is to maintain the initial good quality of the wine and ensure that the wine is bottled to specification. It is critical to prevent oxygen pick-up and manage the DO during the bottling process, specifically wines under screw cap where the headspace is about 9 m∙ of air. This could equate to about 2 mg/∙ DO. This headspace needs to be managed,” she says.

She explains that the liquid nitrogen will expand volume- trically at a ratio of about 700 to 1 and displace all residual oxygen in the empty bottles and headspace, preventing undesirable oxidation by lower- ing the increase in DO levels during shelf life.

“The same technology is also used to increase the internal pressure and ensure rigidity in thin-walled aluminium cans and polyethylene teraphthalate (PET) bottles used for noncarbonated beverages and water. This will prevent the ‘panelling’ effect, allowing for stacking of pallets during warehousing and distribution and enabling the producer to possibly change over to lower-weight PET bottles,” she asserts.

New Trends
Sorore says that the global consumer megatrends of quality, health and safety, as well as ensuring sustainable solutions to customers and taking care of the environment, drive the technological innovations of Air Liquide’s research and development programmes in the wine, brewing and beverage industry.

Air Liquide carbon dioxide (CO2) product manager Annetta van Vuuren says that one of the most common applications of CO2 in the brewing and bever- age industry is carbonation, followed by the manufacturing of dry ice and protective atmospheres in the wine industry.

“CO2 is a by-product of many industrial processes like sugar and alcohol fermentation, chemical manufacturing and petrochemicals refineries. The gas industry captures the CO2 stream, compresses, purifies and liquefies it to conform to the highest international and national standards. All Air Liquide’s CO2 supplied to the wine, beverage and brewing industries are classified as beverage grade, in accordance with South African National Standards,” she says.
Van Vuuren adds that the safety of the company’s gases and installations is paramount for its continued success in the wine, beverage and brewing industries.

“Air Liquide values the safety of its customers, employees and the environment. To that end, we have implemented gas safety and awareness training as a value-added service with special focus on the wine industry,” she explains.

Challenges
The shortage of CO2 every year since 2003, is a significant challenge for the wine industry.

Van Vuuren says that even a minute product like CO2 can bring a halt to production. Air Liquide has been able to enter this market with a new strategy since 2004, which includes the multisourcing of gas, diversifying sources and providing the highest-quality products. The company is now diversifying its sourcing of raw gas into different regions and industries.

The company commissioned another CO2 plant, in South Africa, in 2007. This was the first in South Africa in more than ten years, with a second plant commissioned in Swaziland, in 2008. Currently, the company has six sources of CO2 and aims to expand further.

“We will keep expanding as our business grows so that our customers do not have to expe- rience any interruptions in gas supply. Although it is more expensive to develop a number of smaller plants, instead of one big plant, we want to ensure reliability of supply to our customers,” she adds.

Van Vuuren says that, as wineries are now entering into a harvest period, they are starting to feel the shortage of CO2.

“CO2 is a critical component of the beverage industry, but, unfortunately, demand peaks at a time when supply shuts down. Air Liquide has moved away from that with the diver- sification of supply and the industry has bought into our initiative. We have experienced positive reaction and more contracts,” she asserts.

Sorore says that, according to nonprofit industry organi- sation Wines of South Africa, the modern South African wine industry is a little over a decade old and has had to catch up. Exports grew by 335% between 1995 and 2007 and wine producers started developing a knowledge of international markets and the needs and demands of consumers.

“The challenge for Air Liquide is to remain abreast of these international consumer trends, understand the needs and requirements of our wine- makers and translate the information into innovative, sustainable inert gas solutions that can add value to our local wine industry,” Sorore concludes.