This document discusses the application of high hydrostatic pressure (HHP) technology to food processing. HHP uses water pressures between 100-900 MPa to decontaminate packaged foods while maintaining sensory qualities. It can inactivate microbes and enzymes without using heat or chemicals. HHP is shown to reduce food allergens by disrupting tertiary and quaternary protein structures through rupture of non-covalent bonds. This alters the conformation of allergens and reduces their allergenicity. HHP has potential for developing hypoallergenic foods and decreasing the impact of food allergies.

1. Application of High Hydrostatic Pressure
Gopal Jee Chourasia
Agricultural & Food Engineering Department
IIT Kharagpur 1

2. Contents
• Introduction
• Basic principles
• HHP technology
• Generation of HHP
• HHP products
• HHP application
• Conclusions
• References
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3. 1. Extend shelf life
2. Maintain sensory properties
3. Maintain or improve nutritive properties
4. Ensure safety
5. Make more convenient
Why process food?

4. 4

5. 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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6. working principle
The application of HHP related to 2 basic principles
• Isobaric principle .
• Pascal’s principle.
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7. Diagram of the HHP equipmentDiagram of the HHP equipment
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8. • Solid foods, mainly vacuum packed
• Dry-cured ,Cheeses ,or cooked meat products
• Fish, Seafoods, marinated Products.
• Ready to eat meals, sauces
• Fruits, marmelades / jam
• Liquid Food, in flexible packaging
• Dairy products
• Fruit juices
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Food that can be HHP treatedFood that can be HHP treated

9. 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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10. About colour:
• 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 muscles
activity (depending on processing conditions)
• Proteins are partially denaturized in products where proteins
have not been previously modified by other process: heating,
drying, fermentation .
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Main technological effects of HHPMain technological effects of HHP

11. Processing or formulation factors that canProcessing or formulation factors that can
modify the effect of high pressuremodify the effect of high pressure
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 capacity.
pH:
• Low pH values increase the effect of high pressure
against microorganisms and meat components.
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12. Bacteriocins:
• Some bacteriocins specially nisin, are very effective
combined with high pressure, even on Gram –ve
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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13. Other advantages of high pressureOther advantages of high pressure
• No residues
• Uses only tap water
• Safe for workers
• Very low use of energy
• Accepted by consumers and retailers
• Does not produce
– new chemical compounds
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14. Present range of pressures availablePresent range of pressures available
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15. Processing temperaturesProcessing temperatures
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16. Application
• Food allergy, a common disease, is an
abnormal immune response of an individual
triggered by the ingestion of certain foods.
• The phenomenon that nontoxic proteins in
food with no adverse response in the
majority of individuals lead to allergy
symptoms in a certain sensitive population is
still poorly understood, and no perfect
treatment is currently available.
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17. • Based on different principles including
Enzymatic hydrolysis,
Genetic modification, and
Physical methods .
• The hypoallergenic foods currently available on the market are
primarily manufactured using enzymatic hydrolysis. But the
proteolysis process has a negative impact on food structure
and organoleptic characteristics.
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18. • In addition the high-pressure treatment only affects
noncovalent bonds such as the hydrogen, ionic, and
hydrophobic bonds.
• It induces changes in the physicochemical characteristics and
the functional activity of the biological macromolecules in the
food such as protein denaturation and inactivation of
enzymes and microbes.
• However, the flavor and natural nutrients (such as the small
molecules of amino acids, pigments, peptides,
monosaccharides, fruit acids, vitamins etc) as well as other
low molecular- weight colors and flavors in the food are
unaffected.
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19. • The impact of high pressure on the proteins is related to the
rupture of the noncovalent interactions in the protein
molecule.
• The primary, secondary, tertiary, and quaternary structures of
proteins consist of different types of interactions.
• The primary structure is composed of an amino acid sequence
that is connected by covalent bonds.
• Secondary protein structures change at very high pressure,
likely as a result of cleavage of hydrogen .
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20. • The tertiary structure, which is also called the protein subunit,
shows how the secondary structure domains fold into a 3-
dimensional configuration as a consequence of noncovalent
interactions between amino acid side chains.
• The quaternary structure describes the spatial arrangement
of the subunits, held together by noncovalent bonds.
• Therefore, high pressure has a substantial impact on the
tertiary and quaternary structures of the protein, which are
mainly maintained by noncovalent bonds.
• The tertiary structure of a food allergen is the key to its
allergenicity .
• Therefore, high-pressure treatment has great potential in
reducing food allergenicity.
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21. Conclusions
• To date, investigations on high-pressure-treated foodstuffs
have not revealed any evidence of any microbial,
toxicological or allergenic risks as a consequence of high-
pressure treatment.
• Results of presently available studies suggest that high-
pressure treatment might be used for the specific reduction
of the allergenicity of certain protein families.
• High-pressure treatment has a positive effect on reducing
the allergenicity of food allergens by different mechanisms,
such as protein denaturation, induction of protein
conformational changes or modifications, allergen removal.
• By extraction of allergens, and the promotion of enzymatic
hydrolysis to alter the sensitization of the allergens,
indicating a good development potential of the HPP for a
decrease improvement of food allergies.
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22. Refrences:
• Akiyama H, Imai T, Ebisawa M. 2011. Japan food allergen labeling regulation–
history and evaluation. In: Taylor SL, editor. Advances in food and nutrition
research. Burlington, Vt.: Academic Press. p 137–71.
• Balasubramaniam VM, Farkas D, Turek EJ. 2008. Preserving foods through high-
pressure processing. Food Technol 62(11):32–8.
• Blanc Vissers YM, Adel-Patient K, Rigby NM, Mackie AR, Gunning AP, Wellner NK,
Skov PS, Przybylski-Nicaise L, Ballmer-Weber B, Zuidmeer-Jongejan L, Sz´epfalusi Z,
Ruinemans-Koerts J, Jansen AP, Bernard H, Wal JM, Savelkoul HF, Wichers HJ, Mills
EN. 2011. Boiling peanut Ara h 1 results in the formation of aggregates with
reduced allergenicity. Mol Nutr Food Res 55:1887–94.
• Lopata AL, O’Hehir RE, Lehrer SB. 2010. Shellfish allergy. Clin Exp Allergy 40:850–8.
• Meyer-Pittroff R, Behrendt H, Ring J. 2007. Specific immuno-modulation and
therapy by means of high pressure treated allergens. High Press Res 27:63–7.
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