HIGH HYDROSTATIC

PRESSUREPROCESSING

IN FOOD INDUSTRY

Hydrostatic pressure is the pressure which is exerted on a portion of a column of water as a result of the weight of the fluid above it.

Hydrostatic pressure is what is exerted by a liquid when it is at rest. The height of a liquid column of uniform density is directly proportional to the hydrostatic pressure. 

Hydrostatic Pressure (Pa, N/m2) = Height (m) x Density(kg/m3) x Gravity(m/s2) 

Hydrostatic Pressure : Description

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.

Also known as Pascalization.

High Pressures applied at short periods of time(15 minutes).

High hydrostatic pressure processing : Description

Why high pressure processing is required?

• No Thermal Degradation

•Sensory Characteristics are intact.

•Successful Microbial Inactivation

•Extended Shelf Life

•No thermally induced flavours

High Pressure Processing : Process Mechanism In a typical HPP process, the product is

packaged in a flexible container (usually a pouch or plastic bottle) and is loaded into a high pressure chamber filled with a pressure-transmitting (hydraulic) fluid.

The hydraulic fluid (normally water) in the chamber is pressurized

Pressure is applied for a specific time, usually 3 to 5 minutes.

The processed product is then removed and stored/distributed in the conventional manner

Diagram of the HHP equipmentDiagram of the HHP equipment

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Present range of pressures Present range of pressures availableavailable

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Food that can be HHP treatedFood that can be HHP treated

• Solid foods, mainly vacuum packed

- Dry-cured or cooked meat products

- Different kind of Cheese

- Fish, seafood, marinated products

- Ready to eat meals, sauces

- Fruits, marmalades / jams

- Vegetables

• Liquid foods, in flexible packaging

- Dairy products

- Fruit juices

- Nutraceutical formulations

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Processing or formulation Processing or formulation factors that can modify the factors that can modify the

effect of high pressureeffect of high pressure

• Temperature

• pH

• Bacteriocins

• Water activity

• Preservatives

• Combination with other technologies

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Advantages of high pressureAdvantages of high pressure

•Very low use of energy

•No residues: uses only tap water

•Safe for workers

•Accepted by consumers and retailers

•Does not produce

– new chemical compounds

– radiolytic by-products

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Examples of uses of HHPExamples of uses of HHP

Dry-cured meat:

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Examples of uses of HHPExamples of uses of HHP

Ready meals: