What is HPP?

Pascalization, bridgmanization, or high pressure processing (HPP), is a method of preserving and sterilizing food, in which a product is processed under very high pressure, leading to the inactivation of certain microorganisms and enzymes in the food. The technique was named after Blaise Pascal, a French scientist of the 17th century whose work included detailing the effects of pressure on fluids. During pascalization, more than 50,000 pounds per square inch (340 MPa) may be applied for around fifteen minutes, leading to the inactivation of yeast, mold, and bacteria.

Pascalization stops chemical activity caused by microorganisms that play a role in the deterioration of foods. The treatment occurs at low temperatures and does not include the use of food additives. From 1990, some juices, jellies, and jams have been preserved using pascalization in Japan. The technique is now used there to preserve fish and meats, salad dressing, rice cakes, and yogurts. An early use of pascalization in the United States was to treat guacamole. It did not change the guacamole’s taste, texture, or color, but the shelf life of the product increased to thirty days, from three days without the treatment. However, some treated foods still require cold storage because pascalization does not stop all enzyme activity caused by proteins, some of which affects shelf life.

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General Information on Bacteria

The content on this page is intended to provide the non-science reader some basic definitions and background information on the bacteria and bacteria related illnesses. This information will be useful in providing some insight into the benefit of high pressure pasteurization, if you the reader understand the significance of these pathogens.

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What is AutoFrettage?

AutoFrettage is a metal fabrication technique in which a pressure vessel is subjected to enormous pressure, causing internal portions of the part to yield and resulting in internal compressive  residual stresses. The goal of autofrettage is to increase the durability of the final product. Inducing residual compressive stresses into materials can also increase their resistance to stress corrosion cracking; that is, non-mechanically-assisted cracking that occurs when a material is placed in a suitable environment in the presence of residual tensile stress. The technique is commonly used in manufacturing high-pressure pump cylinders, battleship and tank cannon barrels, and fuel injection systems for diesel engines.

Watch AutoFrettage high pressure video and AutoFrettage Intensifier video.

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HPP Solutions:


Here a listing of questions about Pascalization, High Hydrostatic Pressure Processing, High Pressure processing that we typically get asked during our initial client interviews. These questions are in no particular order.

Question #1: What is High Pressure Processing, HPP, Pascalization?

Answer: We found Wikipedia has a good explanation, Click here.

Questions #2: What food products can be High Pressure Processed?

Answer: In general food products that have water space and PH like; salsas, hummus, wet salads (potato salad, macaroni salad, etc.), ready-to-eat meats, dairy, raw meat, fish, shell fish, fruit and fruit juices, vegetable and vegetable juices.

Question #3: Can Meat be High Pressure Processed?

Answer: Yes, Click here to find our more.

Question #4: Can Seafood be High Pressure Processed?

Answer: Yes, Click here to find our more.

Question #5: Can Dairy Products be High Pressure Processed?

Answer: Yes, Click here to find our more.

Question #6: Can Fruit be High Pressure Processed?

Answer: Yes, Click here to find our more.

Question #7: Can Vegetables be High Pressure Processed ?

Answer: Yes, Click here to find our more.

Question #8: Can Juices be High Pressure Processed?

Answer: Yes, Click here to find our more.

Question #9: Can Salad Dressing be High Pressure Processed?

Answer: Yes

Question #10: Can Fish be High Pressure Processed?

Answer: Yes, Click here to find our more.

Question #11: What bacteria are you typically trying to target with HPP?

Answer: E. Coli, Listeria Monocytogenes, Salmonella.

Question #12: Where does Salmonella come from?

Answer: It can be found wherever food comes in contact with animal feces.

Question #13: Why doesn’t the packaged food explode when it is under all that pressure?

Answer: Because the HPP machine fills up with water so that there is equal pressure on all sides of the package.

Question #14: Do you have to process product after it has been packaged?

Answer: No, however the industry has been focused on post package processing.

Question #15: Where can I test my product for HPP?

Answer: You can call many of the universities that work with HPP and manufacturers of the High Pressure Process Equipment.

Question #16: Can I use my existing packaging for HPP?

Answer: More times than not your existing package will not be rigid enough and the seals not strong enough to withstand the intense pressures of HPP. ANF has partners who are experts in HPP packaging to ease you through the transition.

Question #17: Will I have to make changes to my product if I want to HPP it?

Answer: Most likely your product will need modifications so that it best survives HPP with the taste and texture that it has today. You see HPP will allow you to liberate your product of any preservatives you’ve used in the past to preserve it for delivery to consumers. ANF will help you through the positive reformulation process.

Question #18: How much product can I process in a day?

Answer: The answer is predicated on the pressure and hold times required to get you the bacteria kill you are looking for to reach your goals? ANF will work closely with you to determine throughput requirements and assure your HPP operations keep pace with your production line.

Question #19: How many square feet of space do I need for an HPP Machine?

Answer: A minimum of 2,000 square feet for the machine and a minimal processing area.

Question #20: Will my production floor hold the weight of an HPP machine?

Answer: Most manufacturers are going to call for an engineered floor and footings that are not typical in a production facility.

Question #21: What does a HPP Machine Cost?

Answer: For the most popular machines being purchased today, you are going to spend between $1.75 Million and $2.4 Million approximately for the machine and to get it to your door step.