High Pressure Processing (HPP) Technology Guide | Non-Thermal Pasteurization: Principles, Equipment & Applications

"Preserve that fresh taste for an extended shelf life"—High Pressure Processing (HPP) is an innovative technology that achieves pasteurization without heat. It enables the development of products such as cold-pressed juices and fresh deli foods that use "non-thermal" as a key value proposition.

High Pressure Processing (HPP) is a non-thermal pasteurization technology that inactivates microorganisms without heating by subjecting food to ultra-high pressures of 400–600 MPa (megapascals) in water. 400 MPa is roughly 4,000 times atmospheric pressure—equivalent to the water pressure at approximately 40,000 meters of ocean depth. The fundamental principle underlying this technology is Pascal's principle (isostatic pressure): pressure is transmitted uniformly through the water in the vessel, so every part of the food receives the same pressure regardless of its shape or size.

Mechanism of Microbial Inactivation

Under high-pressure conditions, microbial cell membranes are damaged by the pressure, causing loss of membrane function. This disrupts the intracellular and extracellular balance, leading to cell death. Microbial enzymes and protein synthesis machinery are also denatured and inactivated. Vegetative cells (molds, yeasts, Gram-negative bacteria) are generally adequately inactivated at 300–400 MPa, while Gram-positive bacteria and viruses require 400–600 MPa. For pathogenic bacteria such as Listeria and Salmonella, treatment at 600 MPa for 3–5 minutes can achieve 5-log or greater microbial reduction (over 99.999% kill rate).

Effects on Food Components and Benefits of Non-Thermal Processing

The greatest advantage of HPP is that it does not affect covalent bonds (the bonds that hold small molecules together). Low-molecular-weight nutrients such as vitamin C, B vitamins, polyphenols, and carotenoids, as well as aroma and color compounds, undergo virtually no change from pressure. On the other hand, proteins begin to undergo quaternary and tertiary structural changes above 200 MPa, and irreversible denaturation occurs above 400 MPa. This results in texture changes in meat (a slightly paler appearance) and whey protein denaturation in milk. However, compared to thermal pasteurization, HPP is overwhelmingly superior in retaining flavor, color, and nutritional value, making it possible to produce foods with a "fresh" quality.

History of HPP and Japan's Pioneering Role

Research into high-pressure processing of food dates back to 1899, when Bert Hite in the United States experimented with high-pressure pasteurization of milk. However, it was Japan that first achieved commercial success. In 1990, Meidi-ya launched HPP-treated jam products, making a significant impact on the food industry. From the late 1990s onward, commercial adoption of HPP spread across Europe and North America. Today, more than 500 HPP systems are in operation worldwide. The North American and European markets in particular have seen rapid growth in HPP for cold-pressed juices and processed meats, with the global market estimated at approximately ¥70 billion (about $470 million USD) as of 2025.

HPP technology is applicable to a wide range of food categories. Beverages, processed meats, and seafood are the three sectors where commercial adoption has progressed the most globally. Below are the major application categories with specific examples.

Cold-Pressed Juice & Beverages

This is the most widespread application of HPP, accounting for approximately 30–40% of global HPP processing volume. Conventional low-temperature pasteurization (72°C for 15 seconds) deactivates enzymes and causes 20–40% vitamin C loss, whereas HPP achieves over 90% vitamin C retention and substantially preserves enzyme activity. This produces juices with flavor and nutritional value close to freshly squeezed. The shelf life of untreated cold-pressed juice is 3–5 days, but after HPP treatment it can be extended to 30–45 days under refrigeration. In Japan, the growing health consciousness has driven an increase in HPP juice brands, which are gaining a strong presence in the premium beverage market.

Processed Meats (Deli Meats, Ham & Sausage)

Sliced ham, roast beef, deli meats (sliced meat for sandwiches) and other Ready-to-Eat (RTE) meat products carry a high risk of Listeria monocytogenes contamination, making post-packaging HPP pasteurization highly effective. By treating products in their final packaging, the risk of secondary contamination during slicing and packaging is eliminated. In Europe and North America, many major meat processors have adopted HPP, with hundreds of thousands of tons of meat products treated annually in North America alone. In Japan, adoption of HPP by ham and sausage manufacturers is also advancing.

Seafood (Oyster Shucking & Crustacean Meat Extraction)

A unique application of HPP is the shucking of oysters, lobsters, crabs, and other shellfish. Pressure treatment at approximately 300 MPa releases the adductor muscle from the shell, making it easy to open, and improving meat yield by 20–30% compared to traditional hand-shucking. Microbial levels are simultaneously reduced, significantly improving the safety of oysters for raw consumption. Inactivation of norovirus has also been reported at pressures of 400 MPa and above, making HPP a groundbreaking technology in the oyster industry for both safety and yield.

Guacamole, Dips & Sauces

Guacamole made from avocado was one of the earliest commercially HPP-treated products. Since avocado's flavor is significantly degraded by heat, non-thermal HPP is ideal. HPP is also widely used for chilled dip products including salsa, hummus, and cheese dips.

Baby Food & Pet Food

Baby food, which demands both nutritional value and safety, and premium pet food (raw-meat-based raw diets) are also promising HPP markets. Because thermal pasteurization causes vitamin and enzyme loss, HPP, which ensures safety without heat, has become an indispensable technology for high-value product development. In Japan as well, high-quality pet food brands that highlight HPP treatment as a selling point are on the rise.

HPP systems are large-scale equipment built around a high-pressure vessel. Understanding their configuration and operating parameters is important for evaluating the technical capabilities of potential OEM partners in Japan.

Pressure Vessel

The heart of an HPP system is the cylindrical pressure vessel that contains the food and creates the ultra-high-pressure environment. Vessels are manufactured from special steel in a multi-layer (pre-stressed cylinder) construction. Lab-scale vessels range from 35–55 liters, pilot-scale from 100–200 liters, and commercial production vessels from 300–525 liters. Hiperbaric (Spain), the global market leader, offers a 525L model as its flagship, capable of processing approximately 300–400 kg of food per batch. Vessel design life is 100,000–500,000 cycles, and periodic non-destructive testing (ultrasonic inspection) is mandatory.

Intensifier System and Pressure Medium

Clean water (purified or tap water) is used as the pressure-transmitting medium. An intensifier pump pressurizes the water to bring the vessel to the target pressure. The come-up time (time to reach target pressure) varies by system capacity but is typically about 3–6 minutes to reach 600 MPa. Once the target pressure is reached, the pump stops and the vessel pressure is maintained during the hold time. However, due to adiabatic compression heating, the temperature inside the vessel rises by approximately 3°C per 100 MPa. At 600 MPa, this means a temperature rise of about 18°C from the initial water temperature, making pre-treatment product temperature control essential.

Standard Processing Parameter Ranges

• Processing Pressure: 400–600 MPa (600 MPa being the most common)
• Hold Time: 1–5 minutes (set according to product and target organisms; 3 minutes is the most common)
• Cycle Time: 5–15 minutes (total of loading, pressurization, hold, depressurization, and unloading)
• Processing Temperature: 5–25°C (chilled products are loaded at 5–10°C, factoring in adiabatic compression heating)
• Throughput per Hour: approximately 1,500–2,500 kg/hr for a 525L vessel (varies with cycle time)

Automated Loading and Unloading

For commercial HPP systems, maximizing throughput is critical, and conveyor systems for automated product loading and unloading are standard. Products are loaded into the vessel in plastic carrier baskets. The loading/unloading time is approximately 2–4 minutes, accounting for 30–50% of total cycle time, so optimizing this step directly impacts productivity. The latest systems employ double-indexing systems (which prepare the next batch in parallel) to significantly reduce cycle times.

Major HPP Equipment Manufacturers

The global HPP equipment market is an oligopoly dominated by three major manufacturers. Hiperbaric (Spain) is the largest, holding approximately 60% of the global market share, with a product lineup ranging from 55L to 525L. JBT Avure (USA) has particular strength in 350L-class large units and holds a strong North American market share. Uhde High Pressure Technologies (Germany, a ThyssenKrupp subsidiary) specializes in large custom systems. Equipment prices vary by capacity and specifications, but commercial 525L-class systems cost ¥200–500 million (approximately $1.3–3.3 million USD) or more.

HPP is a powerful pasteurization technology, but it is not a cure-all. To ensure quality and safety, it is necessary to properly understand the characteristics and limitations of HPP and build an appropriate management framework.

Bactericidal Efficacy Against Pathogens

HPP demonstrates high bactericidal efficacy against major foodborne pathogens. Under standard processing conditions of 600 MPa for 3 minutes, numerous studies have reported microbial reductions of 5-log or greater (99.999%+) for Listeria monocytogenes, Salmonella spp., and E. coli O157:H7. Inactivation of norovirus has also been confirmed at 400–600 MPa, although the data is not as extensive as for bacteria, and guaranteeing complete virus inactivation is currently difficult. Yeasts and molds are inactivated at relatively low pressures (300–400 MPa), making HPP efficient for controlling them in beverages and fruit products.

Limitation Against Spore-Forming Bacteria (HPP's Greatest Constraint)

The greatest limitation of HPP technology is that spores of spore-forming bacteria (Clostridium botulinum, Bacillus cereus, Clostridium perfringens, etc.) cannot be inactivated by ambient-temperature HPP. Bacterial spores have an extremely robust structure and survive 600 MPa pressure. Therefore, HPP-treated food must be distributed and stored under refrigeration (10°C or below), not at ambient temperature. Pressure-Assisted Thermal Sterilization (PATS), which combines high pressure with high temperature, has been researched to achieve "commercial sterility" (shelf-stable), but has not yet been commercialized. When setting shelf life for HPP products, storage studies that account for the growth risk of spore-forming bacteria are essential.

Shelf Life Extension Benefits

In addition to microbial reduction from HPP, microbial growth during refrigerated storage is also significantly delayed, so shelf life is typically extended to 2–3 times that of untreated products. Reported extensions include: cold-pressed juice from 3–5 days to 30–45 days, deli meats from 21 days to 60–90 days, and guacamole from 5 days to 30–45 days. However, the extent of extension depends heavily on the product's pH, water activity, initial microbial count, and storage temperature, so product-specific shelf life studies are mandatory.

Influence of pH and Water Activity

The bactericidal efficacy of HPP is influenced by pH and water activity (Aw). In low-pH foods (acidic foods with pH 4.2 or below), HPP efficacy is enhanced, and adequate pasteurization can be achieved at relatively low pressures and short times. This is one reason why HPP is particularly well-suited for cold-pressed juice. In contrast, low-acid foods with pH 5.0 or above carry a higher risk of spore-forming bacteria, requiring stricter temperature management and shelf life settings. Foods with low water activity (Aw below 0.90) have lower microbial growth risk, but HPP's bactericidal efficacy also tends to decrease.

Regulatory Status

HPP is recognized as a safe food processing technology by the US FDA and USDA and is approved for use across a wide range of food categories, including meat products. However, HPP is often classified as an "additional barrier" rather than a "sterilization step," and does not replace GMP- and HACCP-based hygiene management. In the EU, HPP is also treated as outside the scope of Novel Food regulations. In Japan, there are no special restrictions under the Food Sanitation Act (Shokuhin Eisei Ho); HPP treatment itself can be used as a processing aid, though product labeling and hygiene management must comply with standard requirements. When validating HPP, inoculation studies (challenge tests) using target organisms or surrogate indicator organisms are recommended.

HPP equipment is extremely expensive, so owning HPP facilities in-house is limited to large food manufacturers. For SMEs and startups looking to commercialize HPP products, using an HPP tolling service (contract processing service) is the standard approach. Below are the key considerations for OEM outsourcing and cost estimates when working with Japanese manufacturers.

How HPP Tolling Services Work

HPP tolling (contract HPP processing) is a business model where you manufacture and package your products in-house, then bring them to a tolling operator with HPP equipment for high-pressure processing only. In North America, there are numerous dedicated HPP tolling operators, including Universal Pure, American Pasteurization Company (APC), and Safe Pac Pasteurization. In Japan, HPP tolling services are gradually increasing, but the number of operators remains limited compared to Europe and North America. Some beverage and meat processing companies also offer contract processing using spare capacity on their own equipment.

Cost Estimates

HPP contract processing costs vary by volume, product format, and contract terms. Approximate ranges are as follows:

• Processing Cost: ¥30–100/kg (approx. $0.20–0.65 USD/kg); unit price decreases with larger volumes
• Small Lots: The minimum processing volume is typically one batch (300–400 kg for a 525L vessel). For smaller quantities, costs may rise to ¥150–200/kg (approx. $1.00–1.30 USD/kg)
• Annual Contracts: Ongoing relationships with annual volume commitments may bring costs down to ¥20–50/kg (approx. $0.13–0.33 USD/kg)
• Transportation Costs: The cost of shipping products (your factory → HPP facility → distribution point) must also be factored in. Refrigerated transport is mandatory, which tends to add significant cost

Packaging Requirements (Most Critical Consideration)

The most important constraint in HPP is packaging format. Under Pascal's principle, uniform pressure is applied to the product inside the container, causing the packaging to shrink by approximately 15–20% in volume. Therefore, rigid containers such as glass bottles and metal cans cannot be used. Permissible packaging is limited to the following:

• PET Bottles: The most common format. However, they shrink by approximately 15% at 600 MPa, so designs that account for recovery are necessary
• Flexible Pouches (laminated film): Best suited as they conform most easily to volume changes
• Plastic Cups: Lid seal strength must be verified to withstand the pressure
• Vacuum Packs: Commonly used for processed meat products

Pre-consultation with packaging suppliers to develop or select HPP-compatible bottle and pouch designs is recommended. Issues such as label adhesion loss and ink bleeding can also occur, so comprehensive packaging validation is necessary.

Lead Time and Development Flow

HPP product development requires time for optimizing processing conditions and verifying shelf life, so you should plan for 3–6 months from concept to initial production. The standard flow is: lab-scale trials (processing condition screening) → pilot trials (packaging compatibility and quality evaluation) → validation trials (challenge tests and storage studies) → production trials. For well-established categories (such as cold-pressed juice), development timelines can sometimes be shortened by leveraging the tolling operator's existing data.

High Pressure Processing (HPP) is a groundbreaking non-thermal pasteurization technology that achieves sterilization without heat. Here are the key decision points for leveraging HPP.

When HPP Is a Good Fit

• Foods where you want to maintain freshness (cold-pressed juices, deli foods)
• Foods whose quality deteriorates with thermal pasteurization
• Products that highlight "non-thermal" as a selling point
• Natural and clean-label products

Key Points to Confirm with Your OEM Partner

• Whether they offer HPP tolling (contract processing) services
• Whether they can propose suitable packaging given HPP constraints (no glass or metal cans)
• Whether they have experience setting shelf life for HPP-treated products
• Whether refrigerated distribution logistics are in place
• Minimum lot sizes and processing fees

On our platform, you can search and compare OEM manufacturers in Japan that offer HPP capabilities. Start by finding manufacturers that can handle your needs and identify the right partner for your product concept.