Industrial use of PEF systems

Industrial Applications of PEF processing

Stefan Toepfl

We are the world’s leading provider

of Pulsed Electric Field Systems

(PEF) to the food, beverage

& scientific sectors.

Facts & figures

founded in 1983legal form not for profit

organisationCEO Dr. Volker Heinzmembers > 150employees > 160

MORE THAN 150 MEMBER COMPANIES

our greatest reference

DILFacilities

Meat pilot hall

Dairy pilot hall

PEF test centerHPP application center

DILFacilities

Emulsification and drying

Chocolate processing

Extrusion

Atomic force microscopy

DILFacilities

Mechanical workshopParts storage

Mechanical workshop

Mechanical workshop

Electrical lab

PEF science

PEF is based on electroporation and is suitable for use in broad range of food and bio-process applications using low levels of energy.

Cell permeabilisation

Microbial inactivation

Stress response

Cell disintegration

Electroporated cells

Depending on the intensity of the treatment,

the applications are different

PEF: Applications

kJ/kg

Specific energy

Biotechnology Medicine

Potatoes Meat JuicesEffluent

disintegrationBiotechnology

MedicinePotatoes Meat Juices

Effluent disintegration

JonaG

old

contr

ol

2 k

J/k

g

10 k

J/k

g

20 k

J/k

g

enzym

e

JG

+ G

D

contr

ol

5 k

J/k

g

10 k

J/k

g

15 k

J/k

g

enzym

e

0

10

20

30

40

50

60

70

80

juic

e y

ield

[%

]

Size

Reduction

Enzymatic

Treatment

Mixing

Holding

Separation

(Pressing)

Pasteurization

(thermal)

PEF

Treatment

Separation

(Decanter)

Pasteurization

(thermal/PEF)

Juice

Pomace

Extraction

Pectin

Size

Reduction

Juice

Impact of PEF-treatment (2 kV/cm) on Jona Gold (JG) and

Golden Delicious (GD) juice yield using a decanter centrifuge.

Juice yield including an eventual transition of solids to juice

Pulsed Electric Field ProcessingEffects on apple tissue

0 10 20 30 40 50 60 70 80 90

20

30

40

50

60

70

80

90

MA-Xpress

PEF 2 kJ/kg

control

juic

e y

ield

(%

)

pressing time (min)

Juice yield from industrial apple mixture using a

horizontal filter press HPL 200, dependent on press

time and pre-treatment.

2 4 6 8 10 12

20

25

30

35

40

45

50

55

60

65

70

75

80

pressing time (min)

control

3 kJ/kg

6 kJ/kg

enzyme

juic

e y

ield

[%

]

Press curve of Jona Gold mash after different

pretreatments using a wrapped cloth press.

Pressure was increased from 0 to 20 bar in

increments of 4 bar.

Clogging of filter elements Larger surface area

Pulsed Electric Field ProcessingInteraction to subsequent process

10 t/h installation in German fruit juice company

Premium cloudy juice production, using continuous belt press

yield increase + 4 to 6 % in comparison to untreated

Subsequent enzymatic maceration

yield increase + 0 to 2 %

Shift to higher production of premium quality first press

Energy input: 4 to 6 kJ/kg

Pulsed Electric Field ProcessingEffects on apple tissue

KEA-TEC, Beckers Bester 2006

E= 1,8 kV/cm 40 Impulse

0

200

400

600

800

1000

1200

1400

0

0,8

7

1,7

4

2,6

3,4

7

4,3

4

5,2

1

6,0

8

6,9

5

7,8

2

8,6

8

9,5

5

Weg [mm]

Kra

ft [g]

unbehandelt HSI behandeltPEF-treatedcontrol

1.8 kV/cm, 40 Pulses

[mm]

Fo

rce [

g]

Softening of tissue by loss of turgor pressure

Improvement of cutting

Cutting force for potato tissue after a PEF-treatment

control PEF

Pulsed Electric Field ProcessingTissue softening


Standard process: 60°C, 30 min heat treatment

Pulsed Electric Field ProcessingTexture softening

Energy too high, liquid and

solid loss

Sufficient treatment

Pulsed Electric Field ProcessingTreatment intensity

Processes/Energy consumption

Applying PEF to your product will result in the following

benefits within the production

o Replacement of thermal preheater

o Continuous, minimum energy consumption (1/10 of preheater)

o Only 1.4 m³ water consumption per hour (for 55 t/h product)

o Less starch in process water

o Reduced blanching, drying and frying time

o Increased knife durability (up to 60 %)

o Instant start up and shut down

o Reduced ambient heat

o Smaller foot print

Longer knife durability

Due to a softer product the knife durability

can be increased by up to 60 %

PEF

As harder the product as more beneficial

to you. Just think about sweet potato,

cassava/manioc and co

2h

6h

Structural modification

PEF

Scanning electron microscopy images of French fries.

Captured at equal magnification.

untreated

Topographic surface

of raw sliced potatoStructural modification

Smoother cut and softer product

Cutting improvement, new shapes and cuts

New amazing shapes are great with Elea PEF.

Treated sweet potato

Smoother cut and softer product

Yield Increase

• >1 % less starch leakage

into the process water

• Less fines during cutting

• Less breakage

Yield increase >1,5 %

A smooth cut results into less surface area and less oil uptake

Reduced Oil Content

5.7%

Without PEF there is

a higher oil uptake

Etc,etc

Without PEF

Oil Content

5.1%

With PEF

Oil Content

With PEF there is

less oil uptake this results in

Etc,etc

Confocal Laser Scanning pictures of French fries

Reduced Oil Content

Untreated

PEF

Red=oil

Green=protein

0 20 40 60 80

60°C 30min

MEF

PEF

Energy kJ/kg

Energy comparisonCommercial scale potato processing

Short-time continuous

process

Volumetric treatment

Enanced cutting quality,

less breakage and

increased length of strips

With PEF we can generate and accurately measure significant increases in yield,

energy and water savings and improve quality

T H E B E N E F I T S O F P E F F O R F R E N C H F R I E S

LESS HEAT

LOW ENERGY USE REDUCED BLANCHING TIME LESS BROWNING

LESS OIL UPTAKELESS FRACTURE

Pulsed Electric Fields (PEF)Electrifying microbes

E

L

E

K

T

R

O

P

O

R

A

T

I

O

N

PEF treated

untreated

Relevance of Non-thermal Technologies

Control: No PEF treatment

Heat treatment: 90°C-20 seconds

PEF treatment intensitiesPEF 1 13 kV/cm, Tin 40°C, 157 kJ/kgPEF 2 13 kV/cm, Tin 40°C, 182 kJ/kgPEF 3 13 kV/cm, Tin 44°C, 151 kJ/kgPEF 4 13 kV/cm, Tin 44°C, 155 kJ/kgPEF 5 13 kV/cm, Tin 48°C, 165 kJ/kgPEF 6 13 kV/cm, Tin 48°C, 142 kJ/kg

Untreated

PEF 1

PEF 2-6; Heat treatment

The lowest intensity PEF treatment increased the shelf life from 1 week (untreated) to more than 2 weeks. More intense PEF treatments can increase the shelf life up to 60 days under cold storage (4°C).

0

1

2

3

4

5

6

7

0 10 20 30 40 50 60 70

Log

(cfu

/mL)

Days 4°C

Total Plate Count

Pulsed Electric FieldsOrange Juice

Co

ntr

ol

PEF

5

PEF

6

Hea

t Tr

eat.

After one day, the fresh juice presented a clear separation in the pulp, showing two fractions, one floating and as a sediment.

After 21 days, the sedimentation in the treated juices (PEF and thermal) was the same, about 25 mm lower compared to day 1.

The cloud was stable during the subsequent days, reaching a maximum sedimentation of 30 mm compared to day 1.

All the PEF treated juices were comparable to the thermal treated juice. Therefore the enzyme acivity was controlled.

Day 0

Day 61

Day 21

Pulsed Electric FieldsCloud stability

0

0,0005

0,001

0,0015

0,002

0,0025

0,003

UP

E/m

L

PME

PEF: 12.9 kV/cm, 90 kJ/kg, T in 50°C

Thermal treatment: 96°C, 10 s.

PEF can achieve an inactivation in pectyl methyl estherase (PME) comparable to the commercial thermal treatment applied in the industry.

Pulsed Electric FieldsCloud stability

specific energy [kJ/kg]

0 100 200 300 400

IgA

concentr

ation [

µg/m

L]

0

20

40

60

80

100

120

140 IgA

Pulsed Electric Field ProcessingImpact on lgA in milk

36

Tube-in-tube heat exchanger. 1800 L/h. Heat recovery section included.

Pulsed Electric FieldsLine setup

Aseptic tankUNTREATED PRODUCT

Aseptic tankFINAL PRODUCT

PEF unit

TT

T Temperature control

Juice flow

Juice flow

35°C

4°C

55°C

4°C

4°C

*Temperatures shown here are illustrative

To filling line

Conditioning section

Cooling section

The heat recovery section uses the warm product to temper the cold product. Therefore less energy is required to condition the untreated juice and refrigerate the PEF juice.

Heat recovery section

20°C

20°C


0

10

20

30

40

50

60

70

80

90

100

0 100 200 300 400 500 600

Tem

per

atu

re (

°C)

Time (seconds)

The electrical energy delivered to the product is partially transformed into thermal energy. This is a side effect which is less relevant than the electroporation produced during the treatment. The treatment time is in the range of microseconds. Although the temperature peak can reach more than 60°C in high intensity treatments, the thermal load compared to a traditional thermal pasteurisation is much lower.

Temperature/time profile

LTLT pasteurisation

PEF pasteurisation

Thermal energy load Pasteurization units

HTST pasteurisation

HPP

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

2

PU


0 2 4 6 8 10 12 14 16 18 20 2210

0

101

102

103

104

105

106

Mic

robia

l count

(cfu

/ml)

Storage time (days)

untreated: total aerobic count

untreated: yeats and molds

untreated: Lactic acid bacterie

treated: total aerobic count

treated: yeasts and molds

treated: Lactic acid bacteria

detection limit

Shelf life increase of fresh, non-pasteurized smoothies

and other heat sensitive liquids

Pulsed Electric Field ProcessingProduct example fresh juice

(Netherlands)(UK)

(Netherlands)(Germany)

(UK)

SupermarketsProducers

(Netherlands)

(Germany)

(Germany)

Pulsed Electric FieldsCommercial experience

B E N E F I T S F O R G R A P E J U I C E ( l o w p h )

15 DAYSuntreated juice

+45 days extended shelf life

PEF juice 60 DAYS

B E N E F I T S F O R P I N E A P P L E J U I C E ( l o w p h )


After 22 days of cold storage (4 °C) the total plate count had still not reached the

concentration of the untreated juice on the day of production.

B E N E F I T S F O R F R U I T P U R E E S / S M O O T I E S ( l o w p h )


Shelf life extension of Smoothies made from different fruits.

1920 Pasteurization of milk „Electropure Process“

Ohmic Heating and free radical formation

1949 Electroplasmolysis of plant material

B.L. Flaumenbaum, Odessa

1960 Patent, H. Doevenspeck

Phase separation, non-thermal effects on microorganisms

1967 Sale & Hamilton

First systematic studies, Identification of main processing parameters.

Pulsed Electric Field ProcessingHistorical Background

1986 Krupp Maschinentechnik (D) Elcrack® and Elsteril®-Process

1987 MAXWELL Laboratories (USA) Increasing shelf life of liquid products

1988 Institut Prikladnoi Fiziki (USSR) Processing of fruits and vegetables

1993 PURE PULSE (MAXWELL) (USA) Pilot plants for food processing

1995 Universität Charkov (UKRAINE) Pasteurization of Drinks

1992 TU Berlin (D) Pilot scale systems for Preservation and Permeabilization

1995 Unilever (NL) Pilot scale systemOhio State / Washington State University Pilot scale preservation

2000 Emsland Stärke (D) Potato starch extractionFZK (D) Electroporation of sugar beets

2001 Südzucker (D) Industrial prototype for sugar beet treatment

2003 Stork Food Systems (NL) Pilot plant preservation unitSaligus AB (S) Fruit juice preservation

2005 Beckers Bester (D) Fruit juice winning, industrial scaleGenesis Fruit Juice Coop. (USA) Commercial Juice Pasteurization

Pulsed Electric Field ProcessingDevelopment of protoype systems

Heinz Doevenspeck

Volker Stempel

Werner Sitzmann

Pulsed Electric Field ProcessingElectric Treatment of Food

a) switch boxes

b) control unit

c) press outlet

d) screw presses e)

HV-switch

f) capacitor bank g;

screw press,

dismantled

h) ultra filtration unit

Pulsed Electric Field ProcessingElectric Treatment of Food

1990s

Dietrich Knorr, Stefan Boguslawski, Volker Heinz

Pulsed Electric Field Processing

Exponential decay micro- pulse

modulator, 16 kV, 100 J/s

Exponential decay lab scale

pulse modulator, 16 kV, 800 J/s

Exponential decay technical

scale pulse modulator, 24 kV,

8000 J/s

Rectangular technical scale

pulse modulator, 50 kV, 7000

J/s

Exponential decay technical scale pulse

modulator, 20 kV, 5500 (40000) J/s2005

Pulsed Electric Field ProcessingTest circuits

PERPENDICULAR CO-AXIAL CO-LINEAR

Product Flow Product Flow Product Flow

20 kV at 100 Ohm resistance:

Electric power:

Electroporation takes places after 1 µs

Energy delivered in form of pulses (µs), to limit

electric power consumption

“Concentration” of specific energy U (

kV

)

T (s)

AkV

R

UI 200

100

20

MWAkVIUP 420020

Pulsed Electric Field ProcessingEquipment design

Electrical energy is

stored in a capacitor

and discharged into the

treatment chamber

Dependent on

switching technology

and discharge circuit

different pulse wave

shapes can be

obtained

Differences in peak

power capabilities

RC-series PFN

Transformer (spark gap) Marx generator

HV

power

supply

Treatment

chamber

Charging resistor

Storage capacitor

HV-switch

Protective resistor

HV

power

supply

Treatment

chamber

Charging resistor

Storage capacitors

HV-switch

Inductors

Vo

lta

ge

Vo

lta

ge

Time Time

Pulsed Electric Field ProcessingEquipment design

spark gap

capacitor

solid state

switch

treatment

chamber

25 kV 25 kV

5 kV 5 kV 5 kV 5 kV

2.5 kV 25 kV

a

c d

b

30 kW prototype5 kW prototype

Tank Förderpumpe Pulserzeuger

Behandlungszelle

5 kW prototype

2007

Pulsed Electric Field ProcessingSelected protoype systems

5 and 30 kW systems

Capacity up to 15 t/h

Peak voltage 25 kV

Pulse width 4 to 30 µs

Pulse repetition 0 to 1.000 Hz2009

Pulsed Electric Field ProcessingSelected protoype systems

30 kW systemCapacity: up to 10.000 kg/h

for cell disintegrationand 1.800 l/hfor microbial inactivation

80 kW systemCapacity: 50.000 kg/h for cell disintegration

5.000 l/h for microbial inactivation

2013

Pulsed Electric Field ProcessingIndustrial systems

Procédés

Val de Vire expérimente l’électro-

perméabilisation

Isabelle Dulau | 26 Octobre 2010 |


Diversified Technologies

http://www.divtecs.com/product-information/

Treatment chamber

Pilot plant system

Industrial-grade system


Scandinova

www.sc-nova.com/?q=products

K2-series PG-series


Pure Pulse

http://purepulse.eu


http://purepulse.eu/?lang=es

http://purepulse.eu/?lang=es

Nutripulse

http://www.innovation-xl.com/en/nutripulse.html


Pulsemaster

www.pulsemaster.us



Energypulsesystems.pt

Steribeam

www.steribeam.com/


Electroporation in food processingEquipment design database

ManufacturerPower (kW)

Max voltage (kV)

Max Current (A)

Max flow (L/h)

Chambers available Generator Application Coments

References

Blizzar (KEA TEC) 20 t/h belt system

mainly potato treatment, but also other whole or sliced fruits (size diameter 8 cm)

only limited information available

DIL 30 kW 18 30 650 2000 colinear transformer

Continuous treatment liquid food decontamination and cell disintegration 3 phase conection.

DIL 30 kW 18 30 605 10.000 belt system transformer

connection to belt system: treatment of solid material (floating and not floating) 3 phase conection.

DIL 5 kW 3 25 200 200

colinear with gap of 3, 5, 7 and 10 mm), coaxial transformer

Continuous treatment liquid food decontamination

pulse width 4 -32µs, bipolar pulses, 3 phase conection.

DIL 80 kW 75 25 3000 5.000 colinearmarx generator

Continuous treatment liquid food decontamination and cell disintegration 3 phase conection.

DIL 80 kW 75 25 3000 50.000 belt systemmarx generator

connection to belt system: treatment of solid material (floating and not floating) 3 phase conection.

Divtec Industrial - grade PEF system 125 40 300

DTI Patented IGBT switch

extraction, wastwater decontamination

4 kHz max freq. 1 to 11 microseconds pulse width

Divtec lab-scale 1-10 20 100DTI Patented IGBT switch

extraction dehydration, pasteurisation, wastewater 10 to 4 kHz freq.

Divtec Pilot-plat 25 25 300 600colinear 8 mm gap

DTI PatentedIGBT switch

monopolar squared pulses, 1-10 microsecond pulse width, , 3kHz max freq.

Divtec Water decontamination 150 400 500 10000

colinear 15 mm gap

DTI Patented IGBT switch wastewater decontamination

1-10 microsecond pulse width

EnergyPulseSystems 25 Apple, Juice, Microalgae

Hazemeyer/INRA10 kW (?) 5 1000 A 5000 Colinear (?) Cidre production 100 µs

KEA TEC 21 kW 50 1000

cylindrical (stainless steel, polypropylen)

marx generator

Continuous treatment liquid food decontamination and cell disintegration (1000 l/h)

KEA-Wein

Maxwellpulse High current pulse generator 2000 kA

limited website, info to be confirmed via email

Maxwellpulse High power pulse generator

2000 GW


Maxwellpulse High voltage pulse generator 1000


Nutripulse NP 60100 cc batch ohmic heating

220 V suply required, only in batch, for cooking

Nutripulse NP 600800 cc batch ohmic heating

380 V suply required, only in batch, for cooking

Pure Pulse 16 20-40 600Continuous treatment liquid food decontamination

pulse width 1-4 microseconds





Scandinova K1 5-7,5 130-169 110-1243 phase conection. Water cooling

Steribeam (SBS-PEF-SA-1) 3 20 1L batch

parallel and coaxial configuration

Continuous treatment liquid food decontamination and cell disintegration (low conductivities, no spore inactivation)

square wave pulses with pulse width 5-20 µs

Pulsed Electric Field ProcessingTypical range of parameters

Medical Bio and Food

Cliniporator Lab scale Technical scale Industrial scale

Pulse voltage 0.1 – 1 kV 5 – 10 kV 10 – 20 kV 30 – 100 kV

Pulsefrequency

1 – 5000 Hz 1- 500 Hz 100 – 500 Hz 30 – 500 Hz

Peak current 20 A 20 – 200 A 100 – 1000 A 700 – 5000 A

Peak power 20 kW 1 MW 10 MW 500 MW

Average power 0,2 kW 1 – 5 kW 5 – 30 kW 30 – 600 kW

We provide 3 customisable PEF systems

OUR MACHINES

SafeJuice™ process pumpable

liquid and semi-liquid products –

juices, syrups, mash and pumpable

non-foods.

SmoothCut™ systems

process solid products such

as roots, leaves, fruits and

vegetables.

Our trial batch system can treat

solids and liquids for scientific

and pilot scale applications.

Quelle Fotos: DIL,

• Batch system for use as

trial system

• Tech Center / Lab

• CE compliant

• 12 l chamber volume

• up to 300 kg/hr

Pulsed Electric FieldsEquipment


200 l/h for microbial inactivation


1.500 to 1.800 l/h for microbial inactivation


3530.00

3400.00

2100

.00

40 kW systemMarx generatorCapacity: 25.000 kg/h for cell disintegration



80 kW systemMarx generatorCapacity: 50.000 kg/h for cell disintegration



Versatile 800 mm belt system for

large scale processing of solids

Capacity range 30 – 50 t/h

Systems for sinking and floating

products available

Equipment design

Equipment design

10 kW systemCompact designCapacity: 6.000 kg/h for cell disintegration


Pulsed Electric FieldsIndustrial scale equipment

Pulsed Electric FieldsSafety / cleaning

Pulsed Electric Field ProcessingChamber design

Improvement of homogeneity

Shrink-on design

Field concentration chamber

DN 50

Electric field distributionconductivity

Flow patternviscosity, flow rate

Distribution of energy dissipation

Treatment efficiency distribution

Thermal effects distribution

Product – dependent chamber geometry

Pulsed Electric FieldsTreatment homogeneity

Safety Aspects / Novel FoodSafety Aspects / Novel Food

“…. In conclusion, the results obtained in the

present study

clearly demonstrate that PEF does not affect

the composition

of apple juices under the conditions applied,

consistent with

previous findings (19, 24, 25). Hence, this

aspect supported

PEF applicability with respect to the

requirements set by the

EU Novel Food Regulation (EC 258/97)….“

Pulsed Electric FieldsJuice quality

Parameter Method

Soluble dry matter Refractometry

pH Porentiometric (IFU-Method Nr.

11)

Density Density Measurement

Total acid Titrimetric (IFU-Method Nr. 3)

Sugar (glc, frc,

saccharose)

Enzymatic (Testkit; R-Biopharm

AG, Darmstadt, Germany)

Ascorbic acid Enzymatic (Testkit; R-Biopharm


Sorbit Enzymatic (Testkit; R-Biopharm


L-malic acid Enzymatic (Testkit; R-Biopharm


Phenolic compounds HPLC (DAD, MS)

Total phenolics Folin-Ciocalteu

Antioxidant capacity TEAC, FRAP, DPPH

Browning index Photometric (420 nm)

Color L*a*b*-values (Photometric)

Turbidity distribution Mastersizer

Turbidity stability Centrifugation, storage tests Juices compliant with AIJN code of practice

Schilling et al., 2008

Pulsed Electric FieldsJuice quality

Treatment homogeneity – design of chambers

Example: colinear chamber

Electric

Field20 – 40 kV/cm

Flow

Pattern2 – 60 cm/s

Temperature

Field40-84°C

Pulsed Electric Field ProcessingModelling

Process validation

88

1

2

3

4

5

6

7

8

52°C

53°C

55°C

45°C

45°C

46°C

35°C

35°C

Fibre-optic temperature measurement

Measuring pointElectric

Field5-25 kV/cm

Flow

pattern2-60 cm/s

Temperature

Field35 – 70°C

89

Product tank

Storage of untreated product

(T0)

PEF treatment

Energy input and temperature

after the PEF treatment (W, T2)

Preheating of the product (T1)

CCP 2

Final cooling

Filling tank

First cooling and heat recovery

CCP 1

CP 2

CP 1

Process flow diagram

HACCP

90

CCP 1 (T1)

CCP 2 (W, T2)

HACCP

Pulsed Electric FieldsInstalled systems

Installed Systems

1 x 3000 l/h

13 gpm

All of our PEF machines are built on site by specialist engineers.

BUILT IN QUAKENBRÜCK

Pulsed Electric FieldsUpcoming commercial applications

New product development for snacks

Peeling improvement for tomato, prune, apricot etc.

Treatment of grapes (extraction of color, polyphenols) and wine

Microalgae, extraction of valuableingredients

Preservation of heat sensitive, proteinbased liquids

Conclusion

By PEF application an efficient cell disintegration or microbialdecontamination can be achieved

The level of cell disintegration / inactivation is dependent on processingconditions (electric field strength, specific energy input, temperature) aswell as product properties (pH, sugar level)

For freshly squeezed juices a superior product quality results

DIL Systems are marketed by a spin-off company, Elea. Technique is in industrial practice, approx 75 systems in commercial use worldwide

Industrial use of PEF systems

Science

Transcript of Industrial use of PEF systems