An Introduction to High Pressure Processing

Its Role and Potential in the Meat Industry

Created by Austin Lowder (austin.lowder@oregonstate.edu)

For the American Meat Science Association

December 17th, 2014

Agenda

• Define and distinguish

• The equipment and process

• What actually happens under pressure

• How pressure is used in the meat industry

• Considerations for making an HPP product

• Novel uses of pressure

• Questions

HPP Talking Points

• Effective as a food safety intervention

• Extends shelf life

• Non-chemical

• Non-thermal

• Minimal nutritional impact

• Clean label

HPP? HHP? HPLT? PATP? HPSF? HPAT?

Basic definitions

• High pressure processing (HPP) – basic, catch-all definition

• High hydrostatic pressure (HHP) – pressure applied submersed in liquid

• High pressure pasteurization (HPP) – specific application for food safety

• These phrases should be considered identical in a food processing context• Hydrodynamic pressure (HDP) is a different process

Other definitions

• Pressure Assisted Thermal Processing (PATP) • HPP using heated medium

• Also called high pressure high temperature (HTHT) or pressure assisted thermal stabilization (PATS)

• High Pressure Low Temperature (HPLT)• HPP at subfreezing temperatures (solid-solid phase transitions)

• HPP used to freeze/thaw products• High pressure shift freezing (HPSF)

• High pressure assisted thawing (HPAT) or high pressure induced thawing (HPIT)

Components of an HPP system

• Vessel• Contains product and liquid• Must withstand pressure/temperature desired

• Intensifier pump• Forces liquid into chamber to increase pressure• Larger volumes require multiple intensifiers

• Medium• Most modern systems use water

Image from Avure

Components of an HPP system

• Input/output system• Moves product in/out of the vessel

• Basket-conveyor is most common

• Yoke• Holds system together, secures plug

• Chilling/heating units – optional• Maintain process temperature

HPP Systems (antique)

Vessel

Pump

Oregon State 20 L HPP system

Equipment (modern)

Photos from NC Hiperbaric & Avure, respectively

Avure AV-10 system

NC Hiperbaric 55 system

High Pressure Principles

• How high is the pressure?

Atmospheric pressure 14.7 psi 0.101325 MPa1 atm

10 M (33 ft) under sea surface 29.4 psi 0.202650 MPa2 atm

Pre

ssu

re Challenger deep (35,827 ft) 16,100 psi 111 MPa1,100 atm

Typical HPP run 87,000 psi 5,920 atm 600 MPa

High Pressure Principles

• pH is decreased under pressure• Meat, poultry, fish have increased pH

following pressurization (~0.1 units)

• Temperature rises – adiabatic heating• 2-3 °C/100 MPa for meat, 8 °C/100 MPa for fat

a

b

c

High Pressure Principles

• The behavior of water/ice changes due to pressure

• Freezing point of water is -22 °C at 210 MPa

• Ice forms under pressure have greater density than water

c

d

High Pressure Principles

• Protein structure may change• Secondary, tertiary and quaternary structure

are affected

• Enzymes may be activated or inactivated

• Protein filaments may be dissolved

• Protein crosslinking may be induced

e

High Pressure Principles

• Free radicals are formed directly by pressurization >400 MPa

• Cell membranes may be disrupted• Selective diffusivity is degraded/lost

• Exposure of long chain unsaturated fatty acids

• Pressure transmission is instantaneous

f

What is HPP used for in the meat industry?

• Food safety• Listeria monocytogenes control on ready to eat (RTE) meats

• Clean label alternative to antimicrobial additives

• Ensure food safety in alternatively cured products

• Salmonella/E. coli control in fresh poultry

• Salmonella control in pet food

• Oyster/lobster shucking/yield

HPP and food safety

• Effect is based on multiple factors• Pressure level – higher is more effective

• Dwell time at pressure – greater is more effective

• Temperature – depends on the organism

• Product water activity (aW) – greater is more effective

• Product pH – lower is more effective

• Product salt & nitrite level

• Bacterial characteristics

HPP and food safety

• Most common process to combat Listeria is 600 MPa for ~3 minj

• HPP conditions for HACCP plans need to match HPP conditions and product parameters in validation literature• If similar conditions can’t be found then a validation study should be carried

out

Is HPP right for my product?

• What is your organism of concern?

• Is your product raw or cooked?

• What species is it?

• How is it packaged?

• What is the pH? Water activity?

• Are there any baroprotectants in the formulation?

• Is there room in the price for an increase?

Is my product right for HPP?

HPP - 551 MPa, 4 minUntreated

Beef semitendinosus (eye of round) w/ 30 minutes bloom time at 4 °C

Is my product right for HPP?

• The package and product must withstand a 15% volume decrease at 600 MPa

• Vacuum bags and skin packaging work best• Some packaging companies offer dedicated materials for HPP

• Modified atmosphere packaging (MAP) can work with a controlled decompression rate

Image from Avure

Is my product right for HPP?

Q: How much does it cost? A: That depends.

• How much product do you want to pressurize?

• How much can fit in a basket?

• What pressure level? What dwell time?

• What temperature?

• Any further processing or repackaging?

• Shipping to a toll processor? Storage at the toll processor?

• Does a validation study need to be done?

How can I use HPP?

• Option 1: Buy/build your own HPP system• http://www.hiperbaric.com/en (NC Hiperbaric, Spain)

• http://www.avure-hpp-foods.com/ (Avure Technologies, USA)

• http://www.uhde-hpt.com/ (UHDE High Pressure Technologies/Multivac, Germany/USA)

Hiperbaric 525, NC Hiperbaric AV-60, Avure TechnologiesPhotos from NC Hiperbaric & Avure, respectively

How can I use HPP?

• Option 2: Toll processors• http://www.avure-hpp-foods.com/tolling-centers/find-a-tolling-center/

• http://www.hiperbaric.com/en/hpp-toll-processing

What about spore-forming organisms?

• C. perfringens & C. botulinum are very pressure resistant

• PATP is a potential solution• 600 MPa, >90 °C (194 °F)

• Drawbacks• Higher energy cost, more expensive equipment, not as thoroughly researched

as conventional HPP

What are other potential uses of HPP?

• Enzyme inactivation/tenderization

• Minimize quality deterioration during freezing/thawing

• HPP of uncooked frozen products to protect quality (HPLT)

Enzyme inactivation/tenderization

• Low pressure levels (~200 MPa) on pre-rigor meat can positively influence tenderness and water holding capacity

• Drip loss, purge and cook loss may be decreased

g

Pre-rigor pressurized pork (215 MPa,

15s, 33 °C) – from Souza et al., 2011

g

Conclusions

• HPP is a potential solution for Listeria control on most RTE meat products• An increase in shelf life may be expected compared to other post-lethality

treatments

• PATP (given further research) may provide an alternative means for commercial sterilization and shelf stable products

• Development of commercial equipment and a growing number of machines in operation should continue to reduce the cost of HPP

Conclusions

• Pre-rigor HPP may improve quality of hot-boned meat

• Other applications of hydrostatic pressure are probably years away

• Thanks:

• Matthew Morris, Pressure Safe LLC, Portland, OR

• Joy Waite-Cusic, Oregon State University, Corvallis, OR

References

a. Mujica-Paz, Valdez-Fragoso, Samson, Welti-Chanes & Torres. 2011. High-pressure processing technologies for the pasteurization and sterilization of foods. Food & Bioprocessing Technology, 4, 969-985

b. Ransanayagam, Balasubramaniam, Ting, Sizer, Bush & Anderson. 2003. Compression heating of selected fatty food materials during high pressure processing. Journal of Food Science, 68, 254-259

c. Fernandez, Sanz, Molina-Garcia, Otero, Guignon & Vaudagna. 2007. Conventional freezing plus high pressure-low temperature treatment: Physical properties, microbial quality and storage stability of beef meat. Meat Science, 77, 616-625.

d. Chaplin, Water Structure and Science. http://www.lsbu.ac.uk/water

e. Messens, Van Camp & Huyghebaert. 1997. The use of high pressure to modify the functionality of food proteins. Trends in Food Science & Technology, 8, 107-112.

f. Bolumar, Skibsted & Orlien. 2012. Kinetics of the formation of radicals in meat during high pressure processing. Food Chemistry, 134, 2114-2120.

g. Souza, Boler, Clark, Kutzler, Holmer, Summerfield, Cannon, Smit, McKeith & Killefer. 2011. The effects of high pressure processing on pork quality, palatability, and further processed products. Meat Science, 87, 419-427.

h. Otero & Sanz. 2003. Modelling heat transfer in high pressure food processing: a review. Innovative Food Science & Emerging Technologies, 4, 121-134.

i. Lowder, Waite-Cusic & DeWitt. 2014. High pressure-low temperature processing of beef: Effects on survival of internalized E. coli O157:H7 and quality characteristics. Innovative Food Science & Emerging Technologies, 26, 18-25.

j. FSIS Compliance Guideline: Controlling Listeria monocytogenes in post lethality exposed ready to eat meat and poultry products. January 2014. Available at: http://www.fsis.usda.gov/wps/wcm/connect/d3373299-50e6-47d6-a577-e74a1e549fde/Controlling_LM_RTE_Guideline_0912?MOD=AJPERES

Other recommended references:

a. Bajovic, Bolumar, Heinz. 2012. Quality considerations with high pressure processing of fresh and value added meat products. Meat Science, 92, 280-289. (Quality/shelf life)

b. Simonin, Duranton, Lamballerie. 2012. New insights into the high pressure processing of meat and meat products. Comprehensive Reviews in Food Science and Food Safety, 11, 285-306. (Food safety/pathogen inactivation)