High pressure processing (HPP) provides the benefits of high-heat pasteurization without the negative effects on taste, texture and nutrition. The HPP process extends shelf life and allows products to carry clean labels on ingredient lists as well.

In the beginning

Listeria outbreaks occurred with a much higher frequency before HPP became a regular step in the process of packaged meats.

“Processors also had the option to rely on an additional thermal processing step once the product was contained in its packaging, at the expense of nutritional and sensory properties,” says Vinicio Serment, US Applications Manager for Hiperbaric.

According to Serment, HPP use for food safety in the ready-to-eat (RTE) meat industry, “…practically eradicated Listeria outbreaks associated with the consumption of RTE meats.”

In 2002, Hiperbaric installed the first horizontal HPP unit in the Campofrio meat factory in Spain. Today, the company continues to innovate and push the HPP industry and food safety forward.

“Hiperbaric annually allocates 7 to 10 percent of revenue to R&D projects for continuous improvement,” Serment says.

Hiperbaric’s staff of scientists collaborates with industry, government, research institutions and universities to address food safety, advancement in HPP technology and the training of students worldwide. Projects have included the evaluation of lactic acid and the inhibition of spores, which HPP does not easily eliminate, and the screening of different subspecies of Listeria to identify those with the greatest resistance to pressure in raw, cooked, cured and fermented meat products.

“In other projects, at the Univ. of Burgos in Spain, researchers discovered a non-pathogenic Listeria subtype that exhibits higher pressure resistance compared to Listeria species that cause illness,” Serment says. “According to the research findings, the new non-pathogenic Listeria subtype may be used to lower expenses of validation studies, since experiments with pathogens require highly trained people and specialized infrastructure due to its hazardous nature.”

JBTAvure, another major player in the advancement of HPP’s food safety attributes has found other ways to continuously improve all that HPP has to offer.

Spray dried hemoglobin

Spray dried hemoglobin (SDH) is the result of passing cow blood through a spray dryer and turning it into a powder. Errol Raghubeer, Ph.D., senior vice president, HPP science and technology at JBTAvure, says mixing SDH into the trim before grinding allows raw ground beef to retain its color after the HPP process extends its refrigerated shelf life.

“The influence of SDH has nothing to do with the microbial kill,” Raghubeer says. “That’s something, we really looked at to make sure it doesn’t interfere or promote the growth of microorganisms.”

Raghubeer went on the say HPP damages the meat’s myoglobin, which gives the tissue its color. Adding the SDH to the trim before the grind helps retain the meat’s natural color. This enables the meat to stay red longer during refrigeration. He and his team have tested different concentrations of SDH and found 0.4 percent retained the best color compared to HPP meat with no SDH.

“We are locked in with the color, but there are some other hurdles we have to overcome,” Raghubeer says. “One is the labeling and if it requires labeling, and that is in front of the USDA, currently. Secondly, there are some textural changes that we are looking at, we’re still experimenting with different grinding processes to see if we can minimize those textural changes that you get with pressure being applied to ground product. Because you have a compaction issue, that can be a little bit of a hurdle. We are working on that.”

While USDA’s timeframe on labeling protocol remains unknown, JBTAvure is conducting research at three locations to address the textural issues. Experiments are being conducted at its corporate laboratory in Erlanger, Kentucky, as well as at an unnamed university and another at a grinding equipment supplier’s facility. The textural experiments were slated for completion by the end of October [2019].

SDH is currently available in the US marketplace, and it has been used in food for human consumption in other countries, but not in the US yet.

“That is why we’re going through this approval process with USDA,” he adds. Raghubeer will present SDH as a part of HPP in both Australia and Japan in November to pursue implementation internationally depending on regulations around the globe.

“Because we don’t have stringent regulations in other parts of the world, we’re hoping to maybe get some of this available commercially outside of the US as well,” says Lisa Wessels, marketing director with JBTAvure.

Safety imprint

Deli meat and other consumer packaged goods (CPG) companies in the meat industry want to make sure specific products have undergone HPP with the right amount of pressure and time for the necessary microbiological results. In September of this year, Chromatic Technologies Inc. (CTI) introduced its line of BlindSpotz HPP indicator products.

“Our scientists developed the HPP indicators because of customer need,” says CTI Product Director Barry McCann. “We heard from major CPG brands that they wanted a quick visual way to know if an individual packaged food product had been through the HPP process.”

CTI worked with its manufacturing partners, HPP tollers and brands to perfect its formulas for the different HPP “recipes,” required by the variety of products that utilize HPP. Variables include fluctuations in pressure per square inch (PSI), time under pressure and water temperature.

“In the end, we developed four HPP indicators in blue and aqua to cover the gamut of processing conditions,” McCann says. “We also had to deliver this technology in a printable ink, which meant making it available in several commercial printing formats: UV Flexo, Water-based Flexo and Gravure, Wet Offset, UV Wet Offset, UV Dry Offset and more.”

CTI’s technology involves encapsulated materials carried in an ink vehicle. Isostatic (equal from every direction) pressure during HPP brings the capsules together at the right combination of PSI, time and chamber water temperature.

“We ‘tuned’ each HPP recipe formula to change color at the target pressure (50K, 70K and 87K PSI), time held at that pressure and the operating chamber water temperature,” McCann says.

Each processor has options and can decide how they want to use the BlindSpotz technology within their business. Processors can use BlindSpotz strictly as an in-house quality check, in which case the ink would be printed on primary packaging when there’s a secondary packaging. Some brands will use the BlindSpotz technology as brand transparency or a differentiator.

CTI partners with companies throughout the supply chain, from processors to packaging and film manufacturers, and from printers to the brands themselves, typically working with two to three value stream partners.

“HPP indicators can be printed directly on product package films, labels and even closures,” McCann says.

The ease and versatility of printing makes the technology a cost-effective tool throughout the supply chain.

Tolling for service

For processors without access to HPP in-house, tolling stations exist and offer third-party services. Villa Rica, Georgia-based Universal Pure provides HPP services from five different facilities in four different locations to service several regions.

“The company specializes in serving food manufacturers who wish to avoid the capital expense of HPP equipment or have additional HPP volume beyond their in-house HPP capabilities, or who need additional value-added services,” says Thomas Woodward, chief commercial officer at Universal Pure. “The forecasted evolution of the HPP market makes this an exciting time to be the leader in the space. We are committed to continued excellence and expansion in HPP services for our growing customer base.”

With more customers than ever voting for clean labels with their shopping choices, and HPP giving processors the ability to extend shelf life without the use of preservatives, HPP appears to have a strong future.

“As HPP continues to expand across new product categories and applications, the market value of HPP foods will increase significantly,” Woodward says.