Technology Reference / Non-Thermal & Cold Preservation / High-Pressure Processing (HPP)

Non-Thermal & Cold Preservation

High-Pressure Processing (HPP)

Subjecting sealed product to extreme hydrostatic pressure — no heat — to inactivate pathogens while flavor, color, and nutrients survive. The catch: it’s a pasteurization-level step, not sterilization, and treating it as the latter is a real hazard.

Non-Thermal & Cold PreservationThis step lives here: high pressure inactivates pathogens with no heat, so flavor, color, and nutrients survive.See the family Primary Packaging & FillingHPP is done in-package, so the product must be filled and sealed in pressure-transmitting packaging before it reaches the vessel.Fill and seal first Labeling, Secondary Packaging & LogisticsTreated product still needs the cold chain: after the cycle it moves to labeling, case-packing, and refrigerated distribution.Where it goes next

What it is

Pressure does what heat would — without the heat.

High-pressure processing is a non-thermal preservation technology that subjects packaged, sealed product to very high hydrostatic pressure — around 400–600 MPa — for a short time, inactivating vegetative pathogens and spoilage organisms while leaving flavor, color, and nutrients largely intact. The pressure acts uniformly and instantaneously through the package, with no heat.

That uniformity is the elegant part: pressure reaches every point of the product at once, regardless of shape or size, so a whole sealed package is treated evenly in one short cycle.

The levers are target pressure, hold time, come-up, initial product temperature, and packaging suitability. HPP is done in-package, so the packaging is part of the process — it has to transmit pressure and survive the cycle without seal failure or deformation.

Product is filled and sealed in flexible or semi-rigid packaging, loaded into the water-filled vessel, pressurized to target and held for the validated time, then depressurized — with pressure, hold, and temperature recorded and the product kept cold-chain.

Process flow

Product filled and sealed in flexible or semi-rigid packaging (HPP is done in-package)

Packages loaded into the high-pressure vessel; vessel filled with water

Pressurized to the target (e.g. 600 MPa) and held for the validated time

Depressurized; packages removed

Pressure, hold, and temperature recorded; product kept cold-chain

→

A fresh-quality, extended-shelf-life refrigerated product

The leversTarget pressure, hold time, come-up, initial product temperature, and packaging suitability.

Why it matters

It pasteurizes — it does not sterilize.

HPP is chosen to keep a product tasting fresh while gaining safety and shelf life — a genuine win. But its limits are easy to overrun: it inactivates vegetative cells, not spores, so it’s a pasteurization-level, cold-chain step, not sterilization. Treating it as the latter — assuming spore kill and shipping ambient — is a real hazard.

Efficacy depends on a validated pressure-and-hold for the specific product, suitable packaging, and an unbroken cold-chain afterward. The discipline is a validated, per-cycle-recorded pressure and hold for the target organism, the product handled as refrigerated rather than shelf-stable, packaging qualified for HPP, assured cold-chain downstream, fill and headspace controlled for pressure transmission, and incoming microbial load controlled upstream rather than leaned on HPP to fix.

21 CFR 117 · PCHFPreventive Controls for Human Food: HPP is a process preventive control, so the lethality step needs a validated pressure/hold, monitoring, and records under your food-safety plan.

21 CFR 120.24 · 5-log reductionThis is the juice HACCP requirement: a juice processor must achieve a 5-log reduction of the pertinent pathogen, which HPP commonly delivers; for non-juice foods that lethality is instead validated as a process preventive control under the 21 CFR 117 plan already cited above.

21 CFR 1 Subpart O · cold-chainHPP pasteurizes but does not sterilize, so the finished product stays refrigerated and moves under the FSMA sanitary-transportation rule to hold that safety.

Package qualificationBecause the cycle runs in-package, the packaging is part of the process: it must transmit pressure and survive come-up and release without seal failure or deformation.

Governed by 21 CFR 117 PCHF with a validated ≥5-log lethality from a process authority; pasteurization-level (no spore kill) so cold-chain is required, plus package qualification.

How it compares

Why a maker reaches for pressure — and what they trade.

HPP buys fresh quality with safety. Knowing what it was chosen over tells you what the product prioritized.

vs.

Thermal pasteurization

Thermal is cheaper, continuous, and not package-shape-limited.

The tradeHPP keeps fresh sensory quality and nutrients heat would cost.

vs.

UHT / retort (sterilization)

Those give ambient shelf stability.

The tradeHPP reduces organisms but stays refrigerated and doesn’t reliably kill spores.

vs.

UV / other non-thermal

UV treats clear liquids and surfaces.

The tradeHPP treats opaque, whole-package product UV can’t reach.

Where it tends to go wrong

The gaps a reviewer looks for on an HPP operation.

None of these are exotic. They’re the quiet places HPP gets overrun — recognizable the moment you’ve run a vessel.

HPP is treated as sterilization (assuming spore kill) — it’s a pasteurization-level step requiring cold-chain.

Pressure/hold isn’t validated for the specific product and pathogen, or isn’t recorded per cycle.

Packaging isn’t qualified for HPP — seal failures or deformation; a breach defeats the in-package treatment.

Cold-chain after HPP isn’t assured, allowing survivor or spore outgrowth.

Headspace or fill issues impair pressure transmission.

HPP is leaned on to fix raw-material microbial load rather than controlling it upstream.

If this is your operation

Six things to check against your own records.

Not an audit — a read you can run yourself before anyone else does. Pull one recent cycle and walk it.

Ask whether the pressure and hold are validated for this product and target organism, and recorded each cycle.

Confirm the product is treated as refrigerated/pasteurized, not shelf-stable.

Check packaging qualification for HPP (seals, integrity post-process).

Review cold-chain assurance downstream.

Look at fill and headspace control for pressure transmission.

Ask how incoming microbial load is controlled, not just reduced by HPP.

Applications

The same operation, across very different products.

The product changes — the discipline never does: validate the pressure-hold, qualify the package, hold the cold-chain.

Food & beverage

Cold-pressed juices

HPP juices that keep raw sensory quality with a validated ≥5-log lethality, sold refrigerated rather than shelf-stable.

Food & beverage

Deli meats & RTE proteins

Post-package HPP on sliced meats and RTE proteins as a Listeria control, where cold-chain remains essential.

Food & beverage

Guacamole, dips & wet salads

Fresh dips and prepared salads where heat would ruin texture and color but HPP extends refrigerated shelf life.

Supplement / specialty

Functional & pet products

Functional shots and raw pet diets treated for safety without heat, where the pasteurization-level limit must be respected.

Ways to put this to work

Know the process. Now decide how far to take it.

These doors connect to this technology. None outranks another — pick the one that fits where you are.

Learn it

Training

A course on high-pressure processing and the standard it has to meet — so your team understands the pasteurization-level limit, validation, and cold-chain before they run or review the step.

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Check one record

Service

Send us one record from this step — a pressure/hold validation, a cycle log, a packaging-qualification study — and get a written read on whether it holds up, and what would close the gap.

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