Introduction, working and application of high-pressure processing.

1. HIGH PRESSURE PROCESING
Presented By:
Ruchika Zalpouri
(L-2019-AE-163-D)
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PFE 602- Advances in Food Processing

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Demand for:
• High quality and convenient products
with natural flavour and taste.
• Safe and natural products without
additives such as preservatives.
In order to harmonize all demands without compromising the safety of
the products, it is necessary to implement newer preservation
technologies in the food industry.

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High Pressure
Processing
High Pressure Processing (HPP) is a cold pasteurization
technique by which products, already sealed in its final package, are
introduced into a vessel and subjected to a high level of isostatic
pressure (300–600MPa or 43,500-87,000psi) transmitted by water.
Pascalization
Ultra High
Pressure
Processing
OR OR

4. • Commercial exposure times at pressure can range from millisecond pulse
(obtained by oscillating pump) to a treatment time of 1200 seconds (20
minutes).
• A pressure of 350 MPa applied for 30 min or 400 MPa applied for 5 min
will cause a ten-fold reduction in vegetative cells of bacteria, yeasts or
moulds (Hoover et al, 1989).
INTRODUCTION
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HISTORY
In 1883, Certes was first in history to relate the effects of high
pressure on organisms.
The first commercialised in Japan in the early 1990s by Meidi-
ya for pasteurisation of jams, jellies, and sauces packaged
High pressure treated foodstuffs have been marketed in Japan
since 1990, in Europe and the United States since 1996 and
Australia since 2001

6. HYDROSTATIC PRINCIPLE
• Le Chatelier’s principle: any reaction, conformational change, phase
transition, accompanied by a decrease in volume is enhanced by
pressure
• Isostatic principle: The food products are compressed by uniform
pressure from every direction and then returned to their original shape
when the pressure is released.
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8. MODES OF COMPRESSION
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9. • This technique uses the vessel ends
closures to act as a piston to
build/release the pressure.
• This happens by reducing the specific
volume inside the vessel until the
desired pressure is reached.
Disadvantage:
The restrictions of the dynamic seal between the piston and the vessel obstruct the
applications of this technique for a small-scale laboratory

10. • It employs a high-pressure intensifier
pump to compress a pressure fluid from its
reservoir tank into a pressure vessel,
transmitted through high-pressure tubes.
• This technique is more appropriate for
solids and high viscous liquid food.
• This method also allows pressure to be
released or kept constant at the required
level during the treatment time for several
• minutes.

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PascalizationMethod
Batch Process
Semi-continuous Process
Continuous Process

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SEMI-CONTINUOUS PROCESS
• Direct introduction of food into the high
pressure chamber is a promising alternative
process compared to that of batch one.
• The food is introduced periodically into the
high pressure processing chamber.
• The combination of multiple vessels, which
sequentially, and which are fed by a central
high pressure compressor, can be used to
make continuity in the process.

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• The products flow through an open end
tube system that pressurizes (high-
pressure intensifiers)
• A mean to depressurize the product is
applied that avoids extreme shear and
heating.
• The processed liquid then goes to a
sterile tank to clean and filling

15. ADIABATIC COMPRESSION
HEATING
Due to the compressive work against
intermolecular forces, HPP causes
temperatures to increase in the pressure
vessel. This phenomenon is known as
adiabatic heating.
The act of compression during high
pressure processing will raise the
temperature of both the product and the
compression fluid adiabatically about 3
°C for every 100 MPa
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16. • HPP can alter membrane functionalities such as active transport or passive
permeability
• The leakage of intracellular constituent through the permeabilized cell
membrane is the most direct reason for cell death.
• Inactivation of key enzymes, including those involved in DNA replication and
transcription.
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INACTIVATION
MECHANISM

17. • Vegetative cells, including yeast and moulds, are pressure
sensitive, i.e. they can be inactivated by pressures of ∼300–
600 Mpa.
• At 500 MPa, the nucleus could no longer be recognized, and
a loss of intracellular material was almost complete.
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YEAST AND MOULDS
(Fark and Hoover, Journal of Food Science-Supplement)

18. • Bacterial spores are highly pressure resistant- pressures exceeding
1200 MP are needed for their inactivation.
• Process temperature in the range 90–121°C in conjunction with
pressures of 500-800 MPa for 20 mins have been used to inactivate
spores forming bacteria such as Clostridium botulinum and
Clostridium sporogenes.
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BACTERIAL
SPORES
(Knorr, 1995)

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Temperature and pH
Type of microorganism
Preservatives
Water activity
Food composition
PROCESSING FACTORS THAT MODIFY THE EFFECT
OF HIGH PRESSURE

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21. Comparison Of HPP with Thermal Treatment
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Fresher Taste
Better Appearance
Texture
Nutrition
Heat Sensitive Products
Conducted at ambient or refrigerated temperatures

22. Effect of HPP on Protein
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Pressure processed have visual
similarities to a thermally-processed
hardboiled egg, the taste of the pressure-
treated egg is actually closer to that of a
raw egg.

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APPLICATIONS

24. Fruit juices
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• Juices pressurized at 400 MPa for 10 min at 40°C did not spoil during 2-3
months of storage
Blanching
• The application of pressure (400 MPa, 15 min, 20°C) to the potato sample
not only caused blanching but also resulted in a four-log cycle reduction in
microbial count.

25. Osmotic
Dehydration
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• High-pressure pre-treatments (100–800 MPa) in osmotic dehydration of
pineapple were found to enhance both water removal as well as solid gain
resulted in four-fold greater diffusivity values for water and, two-fold
greater values for solute (sugar).
Frying
• A reduction of 40% in oil uptake during frying was observed, when
thermally blanched frozen potatoes were replaced by high pressure
blanched frozen potatoes.

26. Fish and Meat
Industry
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• RTE meats that are pressure treated at 600 MPa at 20°C for 180 sec, there
were no changes in sensory quality, no difference in consumer
acceptability and a 4 log reduction in Listeria monocytogenes inoculated
product.
Solid Liquid
Extraction
• Extraction of caffeine from coffee using water could be increased by the
application of high pressure as well as increase in temperature.

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Dairy Industry
• The high pressure slightly improved the microbiological quality of milk
without modifying lacto peroxidase activity (a native milk enzyme)
lactalbumin and bovine serum albumin were pressure resistant (400 MPa
for 60 min.).
• The increase in cheese yield was found (at 300 and 400 MPa) in
conjunction with additional lacto globulin and moisture retention.

28. 1. High pressure is independent of time/mass, that is, it acts instantaneously thus
reducing the processing time.
2. It does not break covalent bonds; therefore, the development of flavors alien to
the products is prevented, maintaining the natural flavor of the products.
3. Since high pressure processing is Isostatic (uniform throughout the food); the
food is preserved evenly throughout without any particles escaping the treatment.
4. The process is environment friendly since it requires only electric energy and
there are no waste products
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ADVANTAGES

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• Food enzymes and bacterial spores are very resistant to pressure and
require very high pressure for their inactivation
• Food materials containing entrapped air such as strawberries or
marshmallows would be crushed under high pressure treatment, and
dry solids do not have sufficient moisture to make HPP effective for
microbial destruction
• High capital cost for a commercial scale.
LIMITATIONS

30. EXAMPLES OF USES OF HHP
Dry-cured meat:
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Cooked meat: cooked ham, roasted
chicken, turkey breast, cooked sausages
Ready meals:

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Fastest cycle time (15,000,000
kg/ year.
Juice, beverages, seafood, fruits
and vegetables
AVURE
TECHNOLOGIES

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