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.A great leap forward in freshness

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High electric voltage (20 - 80 kV), in short(1-10 s) pulses-(upto 1000Hz)

Treatment is conducted at ambient, sub-ambient, or slightlyabove ambient temperature.

Treatment time is less than 1 s(generally).

Non thermal method.

Effects include Permeabilization of Cell Membranes

Greatly reduces energy loss & the detrimental changes of thesensory and physical properties of foods (Quass 1997).

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TWO METHODS HAVE BEEN PROPOSED

ELECTRICAL BREAKDOWN

ELECTROPORATION

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Cell Membrane Capacitor filled with dielectric.

Cell has a normal transmembrane

Potential

RESTING POTENTIAL(0.1V)*

Refers to the difference in electrical potential

across the membrane of a cell.

Differences in ion concentrations across themembrane.

Cell membrane is selectively permeable.

*(GUYTON 1986,WEAVER 1993)

CYTOPLASM

CELL MEMBRANE

(INSULATOR)

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Description of Transmembrane Potential

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Fig. Showing part of Cell Membrane in Electric Field

(1) (4)(3)(2)

Membrane

*

*(Critical Electric Field)

(1) Cell membrane without external electric field.

(2) Cell membrane in electric field COMPRESSED.

(3) Reversible Breakdown of cell membrane.

(4) Irreversible Breakdown of cell membrane.

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Temporary destabilization of lipid bilayer and

proteins of cell membranes*

Aqueous Pore Model

- Hydrophilic Pore Formation Occurs in LipidBilayer of cell Membrane

Presence of an induced transmembrane potentialprovides the free energy necessary for structuralrearrangements of membrane phospholipids andthus enables hydrophilic pore formation.**

*(Castro and others 1993).** (Neumann et al. 1989; Tsong 1991)

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PoreFormation

Water Influx &Swelling

Inactive Cell

MembraneRupture

Stages of Electroporation in a cell membrane (Tsong, T.Y. 1990)

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PRESERVATIONMICROBIAL INACTIVATION

E.g Preservation of high quality beverages

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PULSE

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UPTO

SHELF LIFE OF FRESHLY SQUEEZED JUICES EXTENDED

21DAYS

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..460 million consumers within your grasp

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The sales market for fresh juicesused to be restricted to 200 Kms.

PEF Preservation means being able toexpandyour potential sales marketupto a radius of aproximately 1500 Kms

and that means being able to increaseyour market from 30 million consumersto as many as 460 million

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CELLDISINTEGRATION E.g. DEHYDRATION OF FRUITS &VEGETABLES,EXTRACTION OF JUICES & INGREDIENTS.

BY RUPTURING THE CELL TO RELEASE ITSCONTENTS.

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Main Focus: Fruit/Veg juices & Milk

Vitamins,caratenoids,flavanoids,antioxidant cap

Adapted from James Lyng,UCD

PEF inducesWater soluble vitamins ----- no significant reductionFat soluble vitamins ----- no significant reduction

Antioxidant capacity/carotenoids/Flavonoids

General observations

Heat treatments (fruits & veg)antioxidant capacity (severity).

caratenoids/flavanoids (severity).PEF treatments

lesser effect on antioxidant capacity.lesser effect caratenoids/flavanoids.

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SummaryVitamin C: PEF induces Slight Reduction(4-5%) i.e lower as

compared to conventional heat process treatment (20-30%)

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1900 1920 1940 1960 1980 2000 2020

Adapted from Heinz (2007), Zhang(2008)

MILKPAST(ELECTROPURE)OHMICHEATING

(1949)ELECTROPLASMOLYSIS

(1967)RES.SALE&

HAMILTON(IST

SYSTEMATICSTUDY)

2003RES-CELLPERMEATION

2005SUGAREXTRACTION

2006WASTEWATE

RTREATMENT

2007JUICEPRODUCTION

(1981)RES-ZIMMERM

ANN(MEMBRANE

PERMEAB

ILITY)

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James Lyng (UCD INSTITUTE OF FOOD AND HEALTH,Dublin)

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TH.STERL

TH. PAST

EXTR

PEF

PRES

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RESEARCH FACILTIY

COMMERCIAL INSTALLATION

NOT INSTALLED YET ?

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Barbosa-Ca novas, G. Preservation of foods with pulsed electricfield,Washington state university,Pullman, WA,1996.

Lyng,J. Introduction to pulsed electric field,(Share biotech conference at

AIT Thailand).

De Vito,F.Application of pulsed electric field in food processing(P.hd

Theisis),Spain,2006.

Mohamed.M, E.A. and Amer Eissa, A.H. Pulsed Electric Fields for Food

Processing Technology (King faisal university,Saudi Arabia).

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THANK YOU

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