High-Pressure Processing Now Comes in Bulk

March 10, 2020
Recent developments have the potential to make high-pressure processing less exotic and more generally accepted.

High-pressure processing has usually been seen as a marginal, even exotic technology, due in part to its expense. It costs more than most established kill steps because it’s almost always done in relatively small batches of sealed retail packages.

The batch nature of HPP is inherent and probably won’t ever change. But a recent development promises to free HPP users from the shackles of packaging before processing, while opening up their packaging choices.

Speeding up throughput with HPP has mostly been a matter of increasing the batch size and pressurizing the treatment water faster. (The water in the equipment’s tank, at about 87,000 lbs. per square inch, literally squeezes the life out of microorganisms inside a flexible package; achieving that level of pressure takes time.)

Hiperbaric recently commercialized a significant advance in HPP: bulk liquid processing. Intended for beverages and other low-viscosity liquid products, it uses a large pouch to process up to about 500 liters (132 gallons) at a time. To maintain the advantage of the pathogen kill, the liquid is dispensed into packaging that has been treated with hydrogen peroxide, which is generally used for aseptic beverages. Hydrogen peroxide also is used to sterilize the high pressure valve and pipe connecting the processing chamber to the storage tank for each cycle. The sterilizable valve is unique to Hiperbaric, which is pursuing a patent.

This bulk processing machine from Hiperbaric can process beverages and other low-viscosity liquids before packaging.

The bulk machine achieves twice the throughput of in-package HPP treatment, says Carole Tonello-Samson, Hiperbaric’s commercial and applications director. This cuts energy costs per liter in half, and labor by 80%, since there is no need to handle pouches or flexible bottles manually. The bulk equipment also lets the customer use glass or other rigid packaging, which is not an option for in-package HPP.

“Hiperbaric installed its first commercial 525 bulk machine last year at French company Ateliers Hermes Boissons, a co-packer of HPP'd beverages, following a four-year R&D project,” Tonello-Samson says. “We expect 2020 to be a successful year for the bulk HPP machine in the U.S., and are working to secure additional installations.” A larger model, the 1050, is also available.

Pets, babies, cannabis

As HPP moves into the mainstream, suppliers and users of HPP equipment are identifying several product categories as up-and-comers for high pressure treatment: baby food, pet food and products with cannabis components.

The first two are seen as especially likely to benefit from the added safety that HPP can bring. Pet food and baby food have been rocked by scandals, both recent and distant, involving impurity and even intentional adulteration. Both are intended for populations that are beloved and vulnerable, unable to express their desires, which makes consumers – the owners or parents – extra-demanding.

As for products with cannabidiol (CBD) or other cannabis-derived ingredients, HPP is being touted as a way to preserve their potency by avoiding heat treatment.

Errol Raghubeer, senior VP of microbiology and food technology at HPP equipment supplier JBT Avure, says pet food is turning to HPP because of high-profile contamination scandals, and also because of growing advice that pets should not be fed raw, untreated food.

Pet food, baby food and products containing cannabis are all growth areas for high-pressure processing. Photo: JBT Avure

“Pet food has gotten a lot of publicity recently because in many cases, you’ve had some food safety issues,” Raghubeer says. The U.S. Centers for Disease Control “has come out to say that you should stop feeding your pets raw pet food, so many of the companies who have been selling without HPP in their product are turning to HPP now.”

One method, he says, is to use HPP to treat pet food ingredients like meat or vegetables in bulk, increasing their shelf life, then shipping them to processing lines (sometimes in other locations) for final processing.

“They use HPP as a way to clean up the raw materials and then process that raw material in a cleanroom environment,” through dehydration or some other treatment, he says. The primary purpose is to eliminate pathogens in the raw materials.

Universal Pure, a contract processor, uses Avure equipment to process pet food both as ingredients and in its final package. “The decision to integrate HPP into the pet food production and distribution process adds both to product safety and shelf life,” says Tom Woodward, Universal Pure’s chief commercial officer.

HPP can also be an intermediate processing step. That’s how Steve’s Real Food uses it for raw frozen pet food like patties and nuggets made from beef, chicken, pork, turkey and even “turducken.”

Frozen pet food from Steve’s Real Food is treated by HPP in chubs, then formed into patties or nuggets and frozen.

Steve’s Real Food processes these products in bulk chubs on its own equipment, from Hiperbaric. After treatment, it’s removed from the chub and formed into patties and nuggets. HPP treatment yields a 5-log pathogen reduction, which none of the other kill steps that Steve’s tried – acid sprays, biophages, probiotic sprays and environmental controls – could achieve, says company owner Nicole Lindsley.

Steve’s researched and experimented with HPP for a couple of years before deciding to use it, “due to the negative perceptions that the pet food consumer and retailer had to the process,” Lindsley says. At the end of the second year, “we discovered that not only would HPP allow us to mitigate the harmful microbial environment but it would also allow us to preserve the food without chemicals and extend its shelf life,” she says. “This is why we decided to use HPP on all frozen diets.”

Baby food is also seen as a growth area, for several reasons: it’s becoming more upscale, meaning that consumers are more likely to pay the price premium associated with HPP; most of it is semi-solid, which is perfect for the “squeezing” action that HPP uses to kill microorganisms; and it’s increasingly being marketed in pouches instead of rigid containers, which means HPP treatment can be applied to the final, retail package.

HPP-treated baby food is available from several niche marketers, including Little Spoon and Once Upon a Farm Organics. The major challenge is that, like most HPP-treated products, this baby food has to be refrigerated, which makes it less suitable for feedings away from home.

Refrigeration also complicates the supply chain and makes retailers reluctant to stock a new product, which is why Little Spoon is only available through direct delivery. (Once Upon a Farm, on the other hand, is sold at mainstream grocers including Kroger, Whole Foods, Walmart and Target.)


Cannabis has growth potential for foods and beverages in general, and HPP is no exception. With its avoidance of heat treatment and preservatives, HPP fits well with products that use cannabidiol (CBD), the non-intoxicating component of cannabis, as a form of “natural” relief for pain and anxiety.

Honeydrop Beverages is a line of lemonades sweetened with honey and featuring various health-promoting ingredients like turmeric or passionfruit. All Honeydrop products are processed with HPP, including a new line that contains CBD.

CEO David Luk says HPP treatment has always been an integral part of Honeydrop, whose appeal is built around natural, less processed lemonade.

“Anything that’s treated to 180, 190 degrees, which is your typical process for foods and beverages, you kill flavor, you kill vitamins, and you have to put that back in,” Luk says.

Luk admits that he hasn’t done any specific studies on the effect of heat treatment on CBD, but says if heat can degrade vitamins and other nutrients, it’s probably a good idea to avoid heating CBD.
“I haven’t done the testing on hemp extract, but I wouldn’t be surprised if that heat treatment also killed some of the hemp extract,” he says.

High-pressure processing is making progress in both the range of products treated, and its technical capabilities. The day may soon come when it becomes as mainstream as aseptic, ESL or other alternatives to retorting.

Sponsored Recommendations

F&B Manufacturer Implements Powerful Cybersecurity

A leading F&B manufacturer has moved to harness the skills of Rockwell Automation and Claroty to harden their OT and IT defences.

6 Ways to Augment Your Food and Beverage Workforce

Modern digital tools and technologies help attract, retain and empower a modern workforce.

2024 Manufacturing Trends - Unpacking AI, Workforce, and Cybersecurity

The world of manufacturing is changing, and Generative AI is one of the many change agents. The 2024 State of Smart Manufacturing Report takes a deep dive into how Generative ...

Better OT Asset Management Increases Uptime

A food and beverage company streamlines and simplifies its OT cybersecurity to increase system reliability and uptime.