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HighHighHydrostaticHydrostaticPressurePressure

(HHP)(HHP)

Technology presentation

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IntroductionIntroduction

The High Hydrostatic Pressure (HHP) treatment is an athermic decontamination process which consists in subjecting packaged food to water pressures from 100 to 900 MPa.

The pressure applied is isostatically transmitted inside a pressure vessel.

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Diagram of the HHP equipmentDiagram of the HHP equipment

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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

- Cheeses

- 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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Food that can not be HHP treatedFood that can not be HHP treated

• Solid foods with air included

- Bread

- Mousse

• Packaged foods in completely rigid packaging

- In glass

- Canned

• Foods with a very low water content

- Spices

- Dry fruits

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Main technological effects of HHP Main technological effects of HHP in meat productsin meat products

• About color:

– In fresh or marinated meat, the iron in the myoglobin changes

from ferrous to ferric and globin is denatured: the red color is lost

• About texture:

– Inhibition or stimulation of the proteolytic activity in musclesactivity muscles (depending on processing conditions)

– Proteins are partially denaturized in products where proteins have not been previously modified by other process: heating, drying, fermentation …

• About fats and lipids:

– Reversible crystallization

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Treated beef samples (1) Treated beef samples (1)

Top view of the fresh and frozen beef samples treated by HHP

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Treated beef samples (2)Treated beef samples (2)

Cooked samples: view from the top (a); view of the inside (b)

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Treated commercial beef Treated commercial beef products samplesproducts samples

Commercial beef products before and after HHP treatment

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Processing or formulation factors that can Processing or formulation factors that can modify the effect of high pressure (1)modify the effect of high pressure (1)

• Temperature:

– High temperatures increase the effect of high pressure against

microorganisms and meat components

– Sub-zero temperatures can protect fish products components,

keeping reasonable microbial inactivation capacitykeeping capacity

• pH:

– Low pH values increase the effect of high pressure against

microorganisms and meat components

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Processing or formulation factors that can Processing or formulation factors that can modify the effect of high pressure (2)modify the effect of high pressure (2)

• Bacteriocins:

– Some bacteriocins, and specially nisin, are very effective

combined with high pressure, even on Gram – bacteria

• Water activity:

– With higher water activity, more effectiveness of high

pressure processing, but also more recovery from sub lethally

injured microorganisms

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Processing or formulation factors that can Processing or formulation factors that can modify the effect of high pressure (3)modify the effect of high pressure (3)

• Preservatives:

– Lactate addition reduce the initial inactivation of the

microorganisms but it delays its later recovery

• Combination with other technologies:

– Combined processes can improve high pressure effects on

microorganisms

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Benefits of high pressureBenefits of high pressure

• Adapted to sanitize products where heat processing is

inappropriate (dry cured ham, fermented meat products,

sliced ready to eat meat products, etc.)

• Alternative to heat treatments to process foods, inactivating

micro organisms without changing the sensory qualities or

the nutritional values of foods

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Other advantages of high pressureOther advantages 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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Present range of pressures Present range of pressures availableavailable

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Processing temperaturesProcessing temperatures

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Economic dataEconomic data

MODEL Productivity (a) Cost (b)

Wave 6000/55 170 kg/h 0,19 € / kg

Wave 6000/150 425 kg/h 0,14 € / kg

Wave 6000/300 850 kg/h 0,11 € / kg

Wave 6000/420 2 000 kg/h 0,05 € / kg

(a) Filled at 50% volume and processing time 3 minutes at 600 MPa

(b) Calculated for 5 years depreciation, production 280 days/year, 16 h/day

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Industrial motivations to use High Industrial motivations to use High Hydrostatic Pressure treatmentHydrostatic Pressure treatment

• Higher microbiological safety

– Significant reduction of the risks associated with

the presence and growth of pathogens

– Additional preservation treatment applied to the

products after packaging

• Better sensorial quality

– Significant reduction of the sensorial risks

associated to the presence and growth of alteration

microorganisms (fresher flavour)

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Reasons for the industrial use Reasons for the industrial use of HHP of HHP

• Consumer satisfaction

– Fresher flavor

– Healthy or convenient attributes

• Legal requirements

– Related to food safety

– Related to export regulations

• As a reaction in front a food crisis

• To meet costumers’ specifications

• Shelf life extension

• Image of innovative company

– Both to retailers and end users

– Producing safer and reliable products

• Technology fully accepted by consumers

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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

Cooked meat: cooked ham, roasted chicken, turkey breast, cooked sausages

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Examples of uses of HHPExamples of uses of HHP

Ready meals:

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Obstacles for the implementation Obstacles for the implementation of HHP (1) of HHP (1)

• Low level of public knowledge about the technology

• Attitude of the public administrations in Europe

– Legal risk perception: no explicit authorization in most cases

– Lack of an explicit support for a wider use of the technology

• Image of high cost

– Real costs are lower than perceived costs

– Need of processing centers providing HPP contract processing

to SME’s

• False image of high technological sophistication

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Obstacles for the implementation Obstacles for the implementation of HHP (2) of HHP (2)

• Reduced number of suppliers for equipments

– More options available would encourage a more active market

• Perception of economical risk

– Doubts about mechanical and structural reliability (unjustified)

– Some fear about the usual quick obsolescence for the first

versions of industrial equipments

– Initial high investment cost (mainly for big companies with need

for simultaneous purchasing of multiple equipments)

– It explains why the average user of high pressure is a medium

size company managed by the owners

– It’s necessary to offer to food companies approved protocols and process validation services for different food matrixes