Press

NEW RESEARCH DISPELS CO₂ MYTHS

07th April 2008 – The use of liquid nitrogen for cooling assures product quality on a par with carbon dioxide use, according to a new study available from Air Products. The report by Dr Chris Kennedy confirms that, contrary to widespread perception, carbon dioxide (CO₂) does not have qualitative benefits over liquid nitrogen (LIN) in cooling in meat mixing and forming applications. This means meat processors can choose freely between the two options without worrying about variations in end-product quality.

The study, ‘Comparison of Chilling Meats by Carbon Dioxide and Nitrogen ,’ looked at the effects of both cooling agents on shelf-life, colouration and dehydration. Because of CO₂’s ability to protect against spoilage in MAP packaging applications, many processors have also used it to chill meats, intending to achieve a potential increase in shelf-life. But the study showed that CO₂ desorbs from meat very quickly after chilling, and is therefore unlikely to have any meaningful impact on shelf-life if it is not also used for subsequent MAP packaging.

Dr Kennedy’s report also showed that meat placed in LIN or CO₂ atmospheres could result in oxygen loss from its surface. This causes a reversion of the bright red oxymyoglobin pigment, which consumers often associated with freshness, to myoglobin – which has a deep purplish red colour. Although CO₂ may lighten this colour slightly, the study proved that all colour changes were reversed when the meat was exposed to a normal atmosphere again.

Looking into dehydration rates, Dr Kennedy found that LIN could actually offer advantages over CO₂. When using similar chilling equipment, liquid nitrogen was found to cause less dehydration than carbon dioxide because surface temperature is reduced more quickly.

“Dr Kennedy’s study will be welcome news for many meat processors,” commented Emma Guthrie, European marketing manager, food and industrial cryogenics, at Air Products. “His research shows they genuinely have the choice between CO₂ and LIN for their cooling and freezing applications and don’t need to be concerned about quality variations in the end product. In fact, more manufacturers may now consider the use of LIN because of its other advantages, including rapid and controlled temperature reduction during mixing and processing.”

A copy of Dr Kennedy’s knowledge paper can be requested by e-mailing: Emma Guthrie

Editor’s note

Air Products (NYSE:APD) serves customers in industrial, energy, technology and healthcare markets worldwide with a unique portfolio of atmospheric gases, process and specialty gases, performance materials, and equipment and services. Founded in 1940, Air Products has built leading positions in key growth markets such as semiconductor materials, refinery hydrogen, home healthcare services, natural gas liquefaction, and advanced coatings and adhesives. The company is recognized for its innovative culture, operational excellence and commitment to safety and the environment. Air Products has annual revenues of $10 billion, operations in over 40 countries, and 22,000 employees around the globe.
For more information, visit www.airproducts.com.

Contact us:
For further information, please contact Hugh Ashworth, Air Products.
Telephone 0800 389 0202
E-Mail: Hugh Ashworth
www.airproducts.com/food

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