Linde's MAPAX LD leak detection system utilizes hydrogen as a MAP indicator.
Testing for leaks in modified atmosphere packaging (MAP) is an imperative step for meat and poultry processors to maximize safety, shelf life, and consequently, profits. MAP packages with leaks require rework which is costly in terms of time and labor, or worse can cause a recall that often results in lost product and customer trust.

From the production line to the retail case, food waste in North America exceeds 350 lbs. per capita, per year, according to Linde LLC, Bridgewater, New Jersey. Depending on the number of MAP packages in a lot where a leak has been detected, the value of the product, and the time it took to package and discover a leak, losses due to a single MAP leak can be surprisingly high. “On a single line, the cost ranges between $270,000 and $500,000 per annum,” says Mark DiMaggio, head of food and beverage industry for Linde, Americas.

Detection methods

Popular current methods of leak detection for MAP include water submersion and testing for carbon dioxide (CO2). The water sumbmersion method requires time and labor and is an off-line system. It can also fail if the leak is too small to produce bubbles. One technician might see bubbles and another may not. Or bubbles can form from trapped air on top of the package signaling a leak while the seal of the package is intact. According to David Bell, president at Alpharetta, Georgia-based Witt Gas Controls LP, water submersion also lacks digital documentation for quality assurance.

However, Bell goes on to say water submersion does have certain advantages such as, “intuitive use, low initial costs and localization of any leaks that may be present.”

Producers can use CO2 MAP leak testing off-line or on-line depending on preference and resources. The method uses a sealed chamber with a sensor that will detect any leaked gas alerting operators to a leak in the package. Both approaches have their place and may align with a specific packer’s needs.

“Highly sensitive gas sensors detect even the smallest leaks with measurements taken within a few seconds,” Bell says. “The package will not be damaged, and within modern equipment, the operation is simple. Furthermore, all leak test data – date, time, name, product and tester – is recorded and digitally archived for documentation purposes.”

Real-time process control with MAP leak detection is a technology that Linde believes creates great value and a definitive solution for processors. Earlier this year, Linde introduced its high-speed, inline MAPAX LD leak detection system to North America at the International Processing Production Expo (IPPE). The new non-destructive test system adds a small volume of hydrogen as an indicator in the MAP mixture at the sealing stage. A sensor in the inline leak detection unit then looks for the hydrogen after the sealed packages enter.

DiMaggio says hydrogen is the smallest detectable molecule Linde could use. Other similar technologies use larger molecules such as CO2, but the larger molecules might not get detected if the leak in the package is small, he adds.

Five to 10 years ago, a company working on the technology that would eventually become the MAPAX LD leak detection system approached Linde. Linde took that technology, finalized the R&D and commercialized it.

Mark DiMaggio

“I got involved about five years ago during negotiations with the patent holders of the technology,” DiMaggio says. “It was really a very exciting R&D process. It is very pleasing to see it come to fruition and be commercialized and now launched in my area of responsibility, which is the Americas.”

Before this launch of the MAPAX LD leak detection system in North America, Linde put it to the test in Europe. The technology of the European and North American systems is identical with slight variations in components and power requirements. The European processes have been validated through multiple trials and Linde has installed the system successfully at three protein plants in Europe, with MAPAX LD production ranging from 45 to 120 packages per minute, DiMaggio says. The difference depends on the belt speed of the MAP production line.

“The value of this technology was well demonstrated in Europe, and our R&D team, technical team, and sales engineering team felt very comfortable launching it at the IPPE this year,” he adds.