What is HPP? All the relevant information about High Pressure Processing

1. What is High Pressure Processing (HPP)?

High pressure processing allows gentle preservation of food by high pressure without additives or heat. To achieve this a pressure of 6,000 bar – which equals roughly the weight of three jumbo jets acting on a smartphone-sized area - is applied to the products. The food is conveyed in special baskets into a high-pressure vessel. It then moves into the machine and is filled with water. Pumps increase the pressure in the vessel, which is applied both immediately and evenly spread leaving no evident crushing effect on the products. Once finished the pressure is reduced and your product has a much longer shelf life and maximum product safety.

What is HPP? Infographic

2. How does High Pressure Processing work?

Products in flexible and water-proof package are conveyed within the plastic baskets into a high-pressure vessel. Water is filled into the HPP vessel and pressurized to pressure of 6,000 bar. Acting instantaneously and uniformly through a mass of a food or independently of the size, geometry and composition, isostatic pressure leaves no evident crushing effect on the products.

High isostatic pressure inactivates food-borne microorganisms and spoilage enzymes in a few minutes, while minimizing the loss of food quality. Upon high pressure treatment the vessel is depressurized and water is drained. Products in baskets are conveyed out of vessel and are ready to consume!

How does HPP work? Infographic

3. How does High Pressure Processing preserve food?

Since high pressure eliminates many food-damaging organisms and can deactivate microorganisms, decay processes are significantly slowed down and in some cases even prevented. For example, some types of fruit no longer turn brown. Flavors and vitamins, on the other hand, consist of very small molecules and do not belong to the group of weak bonds. They are not damaged and remain intact.

High pressure processing has proved particularly effective for fruit products and meat products. Although even very sensitive foods in their final packaging are exposed to this pressure, their appearance and consistency remain unchanged after treatment.

How does HPP preserve food? Infographic

4. Is HPP safe for pregnancy?

HPP food is safe and recommended for pregnant women!

Food-born pathogen Listeria monocytogenes that can cause a condition called listeriosis is 20 times more likely to sicken pregnant women and their newborns, adults older then and people with weakened immune system. Listeriosis can lead to miscarriage or premature birth and diseases of internal organs, skin diseases, respiratory problems and spasms of newborns. Listeria can be found in raw meat or fish, vegetables that are contaminated from fertilizer, and unpasteurized dairy products and ready to eat meals.

HPP at 6,000 bar for only 5 min reduces listeria to below the detection level and inhibits its growth during storage of food. At the same time, food retains fresh-taste and all key nutrients for a healthy pregnancy.

Is HPP safe for pregnancy? Infographic

5. Is HPP safe?

When it comes to food preservation there isn’t anything safer!

The conservation of food has been on people's minds for thousands of years. Humans have developed countless methods and techniques to preserve their food, to make germs and bacteria harmless or to preserve the taste and vitamins.

While ancient techniques such as smoking and curing made it possible to increase the shelf life of food, numerous unintended side effects had to be tolerated: It could not be assumed with certainty that the food was germ-free and fresh, and contaminations frequently occurred as well.

High Pressure Processing is the method that eliminates all these disadvantages. While unwanted microorganisms can survive even under conditions of extreme heat or cold, germs and bacteria are susceptible to changing pressure conditions and can be eliminated by applying pressure.

The result: much longer shelf life and maximum product safety and therefore more satisfied customers.

Is HPP safe? Infographic

6. How does pressure inactivate bacteria?

HPP compromises cellular functions such as DNA replication, transcription, translation already at lower pressures (≤100 MPa) which impairs bacterial growth.

At higher pressures, microorganisms start suffering lethal injuries due to loss of cell membrane integrity and protein functionality. The most sensitive to pressures are molds, yeast and parasites. Inactivation of common bacteria requires higher pressure (300-600 MPa). The most barosensitive are bacterial spores that were found to survive pressures up to 1200 MPa at room temperature.

How does pressure inactivate bacteria? Infographic

7. When was High Pressure Processing invented?

The conservation of food has been a concern of people for thousands of years. Humans have developed countless methods and techniques to preserve their food, to make germs and bacteria harmless or to preserve the taste and vitamins.

Methods such as curing and smoking were early techniques to extend the shelf life of food but came with unintended side effects such as contaminations, which occurred frequently.

This changed in June 1899 when Bert Holmes Hite (1866-1921), a researcher from the University of West Virginia (USA), had demonstrated the inactivation of microorganisms using high hydrostatic pressure for the first time. This was the first document on pressure being used as a food preservation method. An intensive research on HPP followed, which led to design and manufacturing of first commercial units in the early 1990’s. It started with fruit jams in Japan and soon after HPP orange juice was offered in French supermarkets. From then on, number of HPP applications has been steadily increased-from preservation to structural alteration of food and production of added-value food.

When was HPP invented? Infographic