Food Grade Gases For Preservation

Tuesday, June 4th, 2019

Around the world, farmers, innovators, R&D specialists and entrepreneurs are developing technologies to address issues in every aspect of the food system. Food grade gasses provide solutions to several challenges in the industry. By Nalin Amunugama, General Manager, BOGE Kompressoren Asia Pacific.

As the food supply chain becomes increasingly global, the risk of contamination also rises, as evidenced by the number of food recalls in recent years. Consumers’ concerns about food safety have gone beyond bacteria contamination, animal disease, and poor food handling. These days, they are concerned about the use of antibiotics in livestock and pesticides on crops, and if the use of food additives and preservatives are safe. They are also demanding more and better fresh foods as a result of the growing health and wellness megatrend.

Catering to consumers’ year-round demand for variety means food has to travel a long way, from farm to plate, and food loss occurs at all stages of this global food chain. According to the Food and Agriculture Organization (FAO), an estimated 1.3 billion tonnes or one third of all food produced for human consumption is spoilt or squandered before it is even consumed, costing the global economy US$2.6 trillion annually. This is more than enough to feed all the 815 million hungry people in the world four times over. South and Southeast Asia are among the biggest culprits of food waste, contributing to a quarter of the world’s total food waste. Singapore’s National Environment Agency’s figures show that the amount of food waste generated in the country has increased by about 40 percent over the past ten years.

The food industry is under constant pressure to get products to market quickly, safely, and in the best possible condition. Businesses know only too well that they must stay on top of issues and be willing to adapt faster to the changing demographics and environment, and are investing heavily on high-tech food preservation solutions that offer improved shelf-life, freshness, and nutritive value. Players across the supply chain, including manufacturers, processors and logistics providers are leveraging new technologies to scale back on food waste, allowing for larger volumes of food exports and wider options for consumers.

From cold plasma to high-pressure processing and pulse electric fields for heat-sensitive foods, novel methods for food preservation are emerging—designed to reduce spoilage and preserve product colour, texture, flavour and nutrient content. The importance of food grade gases, however, in many of these applications is often overlooked. Gaseous nitrogen, for example, is used in a variety of systems and processes in manufacturing and packaging industries. Often regarded as the industry standard for non-chemical preservation, it is an inexpensive and readily available option.


Smart Packaging For Extended Shelf-Life

When food is packaged, it can be packaged with “low permeability” or “high permeability” membranes, based on the degree of respiration. For example, fruit and vegetables generally have much higher respiration and require the gas exchange to occur to stay fresh.  Low respiration foods such as chips, cheese or spices are packaged with a low permeability membrane that prevents gas exchange.   With Modified Atmosphere Packaging (MAP), the optimal type of membrane can be used to package each type of fruit and vegetable to prevent spoilage from occurring early. This is achieved by displacing oxygen in the pack with nitrogen and carbon dioxide (CO2). The nitrogen simultaneously neutralises the absorption effect of carbon dioxide, and ensures that fragile food products remain fresh and intact during storage and transport, until the seal is broken.

Powdered products shipped around the world are often held in storage for prolonged periods, and   risk taints and off-flavours when exposed to high O2 levels. The patented MAP technology developed by GEA, a leading food processing specialist, effectively removes oxygen from the powder and replaces it with inert gas, and in the process, is able to maintain the flavour of the product over an extended period of time.  Basically, the powder in the hopper above the filler is pre-charged with nitrogen during the transport stage.  A vacuum system is used to transfer the powder, reducing the residual oxygen level to about 1 to 2 percent. The filling system then pre-flushes the bag with nitrogen before filling with gassed powder from the hopper.

With MAP technology, manufacturers can capitalise on the extended cycles, and retailers can avoid recurrent product rotation, removal and restocking, saving on labour and waste disposal fees. The technology is widely used in a variety of applications, from packed salads to chilled ready-to-eat meals, dairy products, and snacks like nuts and potato crisps.


Pure Air For Beverage Processing

In beverage manufacturing, nitrogen is essential to processes like sparging and inerting, and provides internal pressure and rigidity to stabilise thin-walled receptacles like Polyethylene Terephthalate (PET) bottles.  It is also useful in preventing discolouration and undesirable flavours in beverages in non-carbonated drinks like wine, iced tea, fruit juices or milk – by removing dissolved oxygen in the liquids.

For facilities that require continuous nitrogen flow, from processing right up to the filling stage, reliable onsite nitrogen generation is critical. BOGE Kompressoren’s scroll compressor technology, through its Eccentric-Oilfree series, is designed for such sensitive applications. Aluminium spirals in the compressor chamber intermesh without touching, generating pulsation and oil-free compressed air for beverage manufacturing. Once the compressors connect to a nitrogen pressure swing adsorption (PSA) generator, pure compressed air is readily supplied. Nitrogen prohibits further wine fermentation and the formation of bacteria and mould in the bottle, preserving the high quality and taste – even over a lengthy ageing process. In applications like decanting wine, this is exceptionally advantageous.

For more efficient energy use and less wastage, users can easily regulate the power delivery and quantity of compressed air using BOGE’s nitrogen PSA generator.


Quick Freezing For Freshness

For years, consumers held the perception that frozen food was of lower quality than fresh food. However, this perception is shifting rapidly as food companies aggressively target health-conscious consumers with improved freezing technologies that offer simpler ingredients without artificial flavourings and chemicals. Cryogenic technology or cold processing using carbon dioxide or nitrogen has gained traction in recent years.  The process involves injecting liquid nitrogen or CO2 to remove heat and freeze or Individually Quick Freeze (IQF) different types of food within minutes. Ice crystals formed during freezing are known to affect the quality parameters of stored frozen foods. The formation of smaller ice crystals with this ultra-fast solution ably protects the cellular structures of food from damage during cooling and rewarming processes, without compromising on the taste, texture and moisture level of the frozen product, once thawed.

Linde’s CRYOLINE CWI is the latest cryogenic freezer to hit the market. Using a combination of wave-impingement technology, the fully adjustable motion promotes more uniform freezing, and the vibration keeps the IQF products from sticking to each other or to the belt. As individual items are gently tossed, they are impinged with a high-velocity convective flow of cryogenic gas.  Aside from protecting quality, the freezing technology also cuts dehydration losses and improves the shelf-life of products like seafood, poultry and meat.


Closing The Loop On Waste

Around the world, farmers, innovators, R&D specialists and entrepreneurs are developing technologies to address issues in every aspect of the food system. Emerging tech solutions present huge opportunities for the food industry to adopt innovative methods that promote greater resource productivity, storage and logistics capacities to keep ingredients fresher and reduce waste.

By closing the loop, we become guardians of our resources and ensure that our food is sustainable and secure. That’s a win-win for the economy, the environment and the planet.


Further reading:
Less Plastic, High-Class Optics, Excellent Quality: OSI’s Meat In Innovative FlatSkin Packaging
Functional Food Goes Organic
A New Level Of Convenience