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Putting on the Pressure: ‘No Heat’ Way to Zap Pathogens

In the world of food safety, it’s not just about food poisoning outbreaks and recalls. Sometimes there’s some good news to share. That’s the case in breakthroughs and advances in science and technology that can stop foodborne pathogens dead in their tracks. And sometimes that sort of news appears in unexpected places.

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Take, for example, the January edition of Popular Mechanics. In a section about the “Ten Tech Concepts You Need to Know,” readers learn that “this year’s big ideas in tech will make your food safer, make hybrid cars more energy efficient, and sentence overpriced texting plans to death.”

Right out of the gate, at the top of the list, is a USDA-approved food-safety process that the magazine refers to as “Pascalization,” commonly known in the food industry as HPP, or high pressure processing. And while it’s only been used on the commercial level for the past 2 decades or so, the technology has been around far longer than that.

Turns out that none other than French scientist, mathematician  and philosopher Blaise Pascal (1623-1662) conducted research on food preservation. What he came up with — high pressure processing — is what  Popular Mechanics describes as “changing the way we think about food.”

This process doesn’t rely on heat, such as pasteurization; or chemicals, such as preservatives; or irradiation to kill the harmful bacteria on food. And while heat and cooking are good ways to kill bacteria, they can also impair the flavor, texture, color and nutrition of the food. For the most part, the same is true of irradiation.

Under high pressure processing, already packaged products such as fresh hamburger and turkey; processed fruit such as apple sauce; oysters; fish; guacamole; and ready-to-eat meats such as sliced turkey, pastrami and beef are put inside a pressure chamber. Water is then added to the chamber before it is sealed. From there, the pressure is increased to the maximum desirable level and sustained for a set period of time. The chamber is then decompressed and drained and the packaged products are removed.

We’re talking about a lot of pressure. For example, at sea level, air pressure is 14.4 pounds per square inch. In the case of products put under HPP, the pressure ranges from 60,000 to 87,000 pounds per square inch.

And while that sounds like enough pressure to squash or damage the packaged food, that doesn’t happen because the pressure is applied equally on all areas of the product.

The good news is that the pressure zaps foodborne pathogens such as E. coli O157:H7, Listeria and Salmonella, as well as “spoilage” microorganisms such as molds and yeasts — without affecting the nutritional qualities or the taste of the food products. That’s because while it has enough force to significantly disrupt cellular activity, it doesn’t affect the structures of the food components that are responsible for nutrition and flavor.

Another plus is that because HPP is applied when the products are already packaged, it eliminates the possibility of cross-contamination. In other words, the products are free of pathogens when they get to the customers, whether they be grocery shoppers, restaurants, schools or other institutions.  Even so, people preparing the food must follow basic food-safety procedures, such as washing their hands and preventing cross-contamination with other foods or cooking utensils to keep the food safe from foodborne pathogens.

But HPP isn’t a one-step-and-it’s-safe sort of approach to food safety. Companies that use it also follow standard food safety principles all the way down the line.

Last year when Food Safety News wrote about HPP, the big news was that meat-processing giant Cargill had introduced a patent-pending process for a new line of fresh hamburger patties produced under high pressure processing. At the time, the company hailed it as a “natural option for food safety” and a “technological breakthrough.” Until then, no one had figured out how to use high pressure processing on fresh hamburger meat without affecting its taste, texture or appearance.

The patties were slated for the food service industry, with customers such as restaurants saying that they were looking for a “fresh hamburger” option with good shelf life. According to a news release from Cargill, the HPP burgers have double the shelf life of non-HPP burgers. Yet the fresh flavor stays intact and food safety is enhanced.

The company’s name for these HPP burgers is “fressure.” The idea is that the fressure logo could be used on restaurant menus so customers would know the burgers were fresh, not frozen. And while the label advised that the meat be cooked to 160 degrees, the “fressure” burgers gave cooks and chefs the option to cook them to lower temperatures and therefore satisfy customers who wanted medium-rare burgers, for example. Even so, restaurant menus are required to carry a warning that undercooked or uncooked meats and shellfish can pose a risk to human health.

At the time, long-time HPP researcher V.M. Balasubramaniam, Department of Food Science and Technology at Ohio State University, told Food Safety News that this new development on the part of Cargill was “the most promising food-safety innovation in recent years.” And he predicted that the technology would become a key player in food safety.

Ten months later, he echoed similar thoughts in the comments he supplied to Popular Mechanics, pointing out that sauces, fruit juices, guacamole, lunch meats, and fish hold up well to HPP and and that treated versions of these foods can be found in stores today.

He also pointed to falling equipment costs for HPP and the demand for longer shelf life, coupled with a poor consumer acceptance of food irradiation, which he referred to as “HPP’s competition” as reasons that HPP will enter into the mainstream.

Indeed, it’s almost there, with the industry having grown into a multi-billion-dollar business in recent years, he said.

Two Heavy-Hitters

As 2011 came to an end, more news about HPP found its way into mainstream media, thanks to two heavy hitters in the food industry.

The first of these is Cargill, which once again turned to HPP, this time for some of its ground turkey. Michael Martin, spokesman for Cargill, told Food Safety News that in the wake of the company’s August and September 2011 recalls of millions of pounds of ground turkey (triggered by the possible contamination of the product by multi-drug resistant strain of Salmonella Heidelberg), the company explored all current food safety technologies to determine which could be effective at further reducing the potential for foodborne illness.

“One of those is high pressure processing (HPP), which we are using on some ground turkey products packaged in chubs,” Martin said. Chubs are thin plastic packages containing ground meat or poultry, with the ends fastened together with a metal clasp.

Martin said the company continues to evaluate the food-safety value and consumer acceptance of the product undergoing HPP, which is being done by a third-party supplier.

The second heavy hitter to enter the HPP scene late in 2011 was none other than Starbucks. With its purchase of juice-maker Evolu
tion Fresh in November, Starbucks cast its vote for HPP. In acquiring the company, Starbucks emphasized the competitiveness of high pressure processing since juices treated with HPP are never heated.

In the Starbuck’s news release about the purchase of the company, Jimmy Rosenberg, founder of Evolution Fresh and the newly named chief juice office of the company, said that using High Pressure Pasteurization (another term for HPP) to help ensure the inherent nutrients are kept intact during the juicing process is a key point of differentiation for a growing number of the company’s juices.

Rosenberg founded Naked Juice, which is now owned by PepsiCo. Another juice contender, Odwalla, was bought by CocaCola. But companies pasteurize their juices.

Starbucks plans to serve Evolution juices at juice and health bars, in stores, and also at its company-owned retail stores, thus bringing the HPP juices to the attention of about 60 million people worldwide each week.

In an email to Food Safety News, a spokesperson for Starbucks said that juices processed with HPP will be noted as such on the bottle labels.

“As more information becomes available about HPP, we believe customers will seek out these juice products,” said the spokesperson.

The news about Starbuck’s plans for Evolution juices found its way into USA Today and the LA Times, among many other mainstream media outlets.

“For us, this is exciting because Starbucks will be marketing the juice as HPP,” Glenn Hewson, vice president of Global Marketing for Avure, the global leader in HPP food processing equipment, told Food Safety News. Last year, Avure described HPP as “food safety’s best kept secret” and pointed to $3 billion in food products worldwide created with HPP each year.

Among the companies using it for all or some of their products are Hormel, Fresherized Foods, Garden Fresh Gourmet, Perdue, Puro Fruits, SimplyFresco, Maple Lodge Farms, and Wholly Guacamole.

America is the leader in HPP, with Mexico coming in second. HPP products are also being produced in Europe, Japan, Australia, New Zealand and Korea.

And while there’s an additional cost of using HPP, food companies are finding that consumers are becoming increasingly concerned about food safety and that many are willing to pay the extra cost.

Labels

When people learn about HPP, the first question they usually ask is how they can know which foods are processed with HPP.

Unfortunately, said Avure’s Hewson, many companies don’t include that information on their labels, although they do include it on their websites.

With that in mind, Hewson said that manufacturers of HPP products should consider joining the ranks of companies like Fresherized Foods, Maple Lodge Farms and Ifantis in developing HPP branding that tells consumers about the benefits on the technology right on the package.

“Processors will find that branding cements consumer awareness and drives market demand for their products that stand out from the crowd,” he said.

He predicts that before long, there will be an industry mark that signifies that HPP has been used to produce the food items that have undergone the process.

To watch some videos about HPP processing, go herehere, and here.

Companies using HPP are invited to list the products they make with the technology in readers’ comments at the end of the article.

© Food Safety News
  • This is great information, and we should be so excited to the applications. Wonder if it will be used on fresh produce? Thanks, Cookson, this great article shows that solutions come out of challenges and move food safety forward one big step at a time.

  • John

    If this high pressure can kill pathogens by disrupting cellular activity, then I would bet that it must also denature the cells of the food itself. The food may look fine on a macro scale, but what about looking at the food on the cellular level? How do we know this is not denaturing the proteins or dna in the food, which can have unforseen negative affects?
    One study comes to mind, where there were 2 groups of rats that were fed rice. One group received normal rice, while the other group received the same rice after it had been “puffed” by a high pressure process. Every rat fed the puffed rice slowly debilitated and got sick until they died.

  • HPP certainly holds benefits for public health. I also wonder what its limitations might be in retail, and in small food processing establishments.
    For example, let’s consider the current recall of Salmonella-laced meat emanating from the Hannaford retail chain in the northeast. The fact that several Hannaford outlets, in several states, are impacted by this recall reveals that one of Hannafords suppliers had one or more days of sizeable sanitation/contamination problems which resulted in their shippment of contaminated meat to the Hannaford stores. Let’s assume the contamination arrived at Hannaford either in (1) boxed beef (ribs, rounds, chucks, etc), in (2) boneless trimmings, or in (3) chubs of coarse ground beef which are further processed at Hannaford outlets. The article above states that chubs can be treated by HPP. Can someone explain if boxed beef or trimmings can be treated via HPP?
    The cost of HPP equipment, and the floor space required to install and utilize HPP technology will make such technology impractical for small food plants, including retail grocery stores such as Hannaford, Safeway, WalMart, etc. In the meat & poultry arena, most downstream further processors totally depend on outside source slaughter providers for all their meat. I’d like to know if the source slaughter plants can use HPP for 100% of their products which they sell to downstream further processors. If not, HPP will face limitations which should be clearly delineated to American consumers at this time. Unfortunately, consumers and gov regulatory agencies might view HPP as the silver bullet, all-in-all godsend which can make all food safer; thus, should be MANDATED by USDA and FDA at all establishments. Don’t laugh, this is not beyond the realm of government requirements.
    Also, can HPP be used in fresh produce which is sold at retail in loose, unpackaged form? Examples include tomatoes, spinach, lettuce, canteloupe, peppers, sprouts, etc, many of which have caused outbreaks in recent years.
    Another concern I have is the likely expectation of gov agencies that ALL food manufacturers and processors MUST eventually incorporate HPP into their operations? An example is USDA’s current style of HACCP, in which agency actions since 2000 have revealed that USDA secretly expects meat & poultry plants of all sizes should utilize a “One Size Fits All” production protocol. In my very small plant and countless others, USDA personnel continually state that ALL plants should consider implementation of interventions which are so blasted expensive that only the largest high-chain speed plants can afford to implement the technology. Furthermore, the high-speeds of the mega plants contribute to pathogen problems, which is why these largest plants absolutely need every intervention known to mankind, while the snail-speed small plants have a greatly diminished pathogen risk.
    If HPP technology eventually morphs into application for the produce industry, what will happen to small, local produce growers with but a small local marketing area? I respectfully suggest that America prospers when our nation is liberally sprinkled with an abundance of small, local & regional producers.
    I am not criticizing HPP. Rather, I’m asking that someone be bold enough to discuss its potential limitations for certain products. And, USDA and FDA must be upfront here, and be audacious enough to delineate the practical limitations of HPP for products under their authority.
    Eventually, we will be forced to admit that whoever (family kitchens, restaurants, nursing homes, caterers) prepares for consumption food not treated with HPP must still treat such food as risky, and handle it accordingly.
    HPP is undeniably an admirable tool in our intervention arsennal. We simply need to also discuss its probable limitations, and get such discussion into our society.
    John Munsell

  • Sergio Muniz

    Can HPP be used with Tree-nuts (specifically Walnuts)? Since heat is not used with HPP, this could be a replacement for PPO, pasteurization, or steam treatment. However, I do agree with “John” that if the proteins in the bacteria are denatured why not the cellular make-up of the food itself?

  • This is great information, and we should be so excited to the applications. Wonder if it will be used on fresh produce? Thanks, Cookson, this great article shows that solutions come out of challenges and move food safety forward one big step at a time.

  • HPP certainly holds benefits for public health. I also wonder what its limitations might be in retail, and in small food processing establishments.
    For example, let’s consider the current recall of Salmonella-laced meat emanating from the Hannaford retail chain in the northeast. The fact that several Hannaford outlets, in several states, are impacted by this recall reveals that one of Hannafords suppliers had one or more days of sizeable sanitation/contamination problems which resulted in their shippment of contaminated meat to the Hannaford stores. Let’s assume the contamination arrived at Hannaford either in (1) boxed beef (ribs, rounds, chucks, etc), in (2) boneless trimmings, or in (3) chubs of coarse ground beef which are further processed at Hannaford outlets. The article above states that chubs can be treated by HPP. Can someone explain if boxed beef or trimmings can be treated via HPP?
    The cost of HPP equipment, and the floor space required to install and utilize HPP technology will make such technology impractical for small food plants, including retail grocery stores such as Hannaford, Safeway, WalMart, etc. In the meat & poultry arena, most downstream further processors totally depend on outside source slaughter providers for all their meat. I’d like to know if the source slaughter plants can use HPP for 100% of their products which they sell to downstream further processors. If not, HPP will face limitations which should be clearly delineated to American consumers at this time. Unfortunately, consumers and gov regulatory agencies might view HPP as the silver bullet, all-in-all godsend which can make all food safer; thus, should be MANDATED by USDA and FDA at all establishments. Don’t laugh, this is not beyond the realm of government requirements.
    Also, can HPP be used in fresh produce which is sold at retail in loose, unpackaged form? Examples include tomatoes, spinach, lettuce, canteloupe, peppers, sprouts, etc, many of which have caused outbreaks in recent years.
    Another concern I have is the likely expectation of gov agencies that ALL food manufacturers and processors MUST eventually incorporate HPP into their operations? An example is USDA’s current style of HACCP, in which agency actions since 2000 have revealed that USDA secretly expects meat & poultry plants of all sizes should utilize a “One Size Fits All” production protocol. In my very small plant and countless others, USDA personnel continually state that ALL plants should consider implementation of interventions which are so blasted expensive that only the largest high-chain speed plants can afford to implement the technology. Furthermore, the high-speeds of the mega plants contribute to pathogen problems, which is why these largest plants absolutely need every intervention known to mankind, while the snail-speed small plants have a greatly diminished pathogen risk.
    If HPP technology eventually morphs into application for the produce industry, what will happen to small, local produce growers with but a small local marketing area? I respectfully suggest that America prospers when our nation is liberally sprinkled with an abundance of small, local & regional producers.
    I am not criticizing HPP. Rather, I’m asking that someone be bold enough to discuss its potential limitations for certain products. And, USDA and FDA must be upfront here, and be audacious enough to delineate the practical limitations of HPP for products under their authority.
    Eventually, we will be forced to admit that whoever (family kitchens, restaurants, nursing homes, caterers) prepares for consumption food not treated with HPP must still treat such food as risky, and handle it accordingly.
    HPP is undeniably an admirable tool in our intervention arsennal. We simply need to also discuss its probable limitations, and get such discussion into our society.
    John Munsell

  • mrothschild

    Glenn Hewson says: “We have performed tests and trials on tree nuts however the issue is that the nuts have sharp edges which, due to the pressure, punch through the packaging material and let in the processing water.”

  • Mary Rothschild

    Glenn Hewson says: “We have performed tests and trials on tree nuts however the issue is that the nuts have sharp edges which, due to the pressure, punch through the packaging material and let in the processing water.”

  • More suppliers of HPP food processing equipment are entering the market. See Medusa High Pressure Technologies http://www.medusa-hpt.com

  • To John the First: These are good questions. Speaking on behalf of Avure, I can tell you that HPP is applied when the product is in its consumer package. It should not be confused with the manufacturing process that produced the puffed rice.
    To John Munsell: John, you raise several interesting points. I invite you to learn more about HPP in our white paper available here: http://www.avure.com/food/
    In the meantime, a few replies to your concerns: HPP’s primary application as a safety treatment is for packaged, refrigerated foods. The long list of products ranges from RTE meats and fresh juices and cut fruits to dips, spreads, and wet salads, and growing. While the use of HPP for pre-packaged ground beef and ground turkey patties represents a major advance for meat processors, it has never been intended or depicted as a silver bullet for all food categories.
    In many instances, the cost of HPP equipment and the floor space required is being addressed by the rapid increase in contract service providers like APC in Wisconsin, GL Foods in Texas, and Universal Cold Storage in Lincoln, Nebraska.
    There is nary a whisper of HPP as a mandate, but you are quite right about the importance of extending the dialogue!

  • Phoebe

    John: The puffed rice nonsense is an urban legend, an internet hoax you are either believe because you’re gullible, or push because you hope to sell some snake oil. But if trusting in such quackery eases your hypochondria, I suggest you avoid popcorn.

    • Lynn McGaha

      Phoebe,
      This article http://www.examiner.com/article/cereal-the-breakfast-of-toxins supports what John says about the ill effects of rats eating puffed wheat. While the cereal company chose not to publish the study, making it hard to substantiate exactly what is the truth, the issue he raises hardly qualifies as an internet hoax. I found him to be quite reasoned, whereas you are a bit hysterical in your overreaction. Your ignorance is further shown by your comparison of popcorn to a puffed rice product. The high temperature and pressure extruded cereal is subject doesn’t begin to compare to how corn is made into popcorn.

  • Ben

    Have you done a test for Deboning thigh? I have seen that it works with seafood but can the meat separate from the bone In a thigh?