High-Tech Food Preservation Gets A Second Look

Feb 1, 2016

Food scares and an increased demand for organic fruits and vegetables are helping propel interest in high pressure pasteurization. HPP, as it's commonly known, uses ultra-high pressure purified cold water to keep packaged food pathogen-free without the preservatives and can quadruple shelf-life.

But consumers will be hard pressed to find HPP on a U.S. food label. Some speculate companies have so many products that are not HPP (instead using heat pasteurization) they don't want to differentiate. In most cases, the term "natural" signals HPP without additives on the label. Some juice drinks use the term "cold pressed." HPP is written on labels in Asia.

Avure Technologies, with research in Erlanger and manufacturing in Middletown, is one of the leading HPP machine manufacturers.

High pressure pasteurization dates back to the 1890's as a way to pasteurize milk but it took 100 years for the equipment to catch up with the technology. That's when the U.S. Army and university researchers got involved, according to Avure's Errol Raghubeer, senior vice president of HPP science and technology. "What has happened from the mid-1990s to where we are now, there have been significant improvements in the engineering of HPP equipment."

To demonstrate, Avure places sliced meat and freshly squeezed orange juice in a vessel and run through the HPP process.
Credit Ann Thompson / WVXU

Here's how the process works: 

  • Food is hermetically sealed and placed inside a vessel in a HPP machine
  • The vessel fills with cold water
  • The machine generates pressure by forcing more water into the vessel (up to 87,000 lbs pounds per square inch)
  • For juice, the pressure lasts for 90 seconds and 2 to 3 minutes for sliced meat
  • According to Modern Food Microbiology, "During pascalization, the food's proteins are denatured, hydrogen bonds are fortified, and noncovalent bonds in the food are disrupted, while the product's main structure remains intact. Because pascalization is not heat-based, covelent bonds are not affected, causing no change in the food's taste."

Restaurants also use HPP.

According to Avure CEO Jeff Williams, “There are several major food service providers that already utilize HPP to protect their products. Again, it makes them safer by eliminating pathogens and it extends the shelf life so it makes them safer for their distribution system. All the time you are reading about recalls on products on beef, or whether it’s E.coli, salmonella, or listeria. That not only happens to things we would potentially buy in a grocery store, but it’s just as prevalent in various food service chains.”

Future uses:

Food allergies could possibly be a thing of the past. Raghubeer says scientists are testing whether HPP can remove allergens in food. “But there is so much more research that needs to go into that area.”

Also, testing is underway to see if HPP can improve vaccines and baby food and convert foods originally designed to be frozen to be fresh.