nonthermal treatments of fruit and vegetable products

Nonthermal Treatments of Fruit andVegetable Products

• Pulsed Electric Fields• High Pressure Processing • Plasma

Stefan ToepflGerman Institute of Food Technologies DIL e.V.

founded in 1983legal form not for profit

organisationCEO Dr. Volker Heinzmembers > 150employees > 160

DILFacts and Figures

Nonthermal TechnologiesRelevance

Cold Plasma TreatmentApplications

Misra et al., 2014

Thirumdas et al., 2014

Surface decontamination of fruits and vegetables

High Pressure ProcessingIndustrial installations

Source: Carole Tonello

Total machine number installed: 350

Source: Carole Tonello


Source: Francisco Purroy


High Pressure ProcessingOperation

High Pressure ProcessingMicrobial inactivation

350 400 450 500 550 6000

60

120

180

240

300

Apricot

Pear

Apple

Pineapple

alc-free Beer

Tre

atm

en

t T

ime

[s]

Pressure [MPa]

40°C

350 400 450 500 550 6000

60

120

180

240

300

Apricot

Orange

Pineapple

Tre

atm

en

t T

ime

[s]

Pressure [MPa]

40°C

350 400 450 500 550 6000

60

120

180

240

300

Apricot

Orange

Pineapple

Tre

atm

en

t T

ime

[s]

Pressure [MPa]

40°C

L.rhamnosus Schiz. pombe Penicillium Isolate

Microbial inactivation in fruit juices, pressure / time required for 1 log inactivation

Serotype 4b(3987/04)

p-T isokineticity diagrams for 5 log inactivation of 3 pathogenic strains

of Listeria monocytogenes in “Black Forest Prosciutto” (Ham) after 15-

240 s.

Serotype CLIP 74903Serotype CLIP 74902 1/2a

High Pressure ProcessingMicrobial inactivation

Juices & smoothies

• Shelf-life increase.

• Preservation of colour, flavour and vitamins.

• Destruction of pathogens and spoiling microorganisms.

Country Year Product

France 1994 Citrus juices

Portugal 2001 Apple & citrus blended apple juice

Italy 2001 Fruit and vegetable juices

Czech Republic 2004 Broccoli & apple, beetroot, carrot juices

USA 2007 Juices and superfood smoothies

Spain 2007 Smoothies & juices

Australia 2008 Smoothies & juices

Northern Ireland 2008 Wheatgrass & broccoli sprout juices

The Netherlands 2009 Smoothies & Juices

USA 2010 Citrus juices

Korea 2010 Juices and smoothies

Italia 2010 Smoothies

UK 2011 Apple juices

USA 2011 Coconut water

USA 2011 Super fruit and vegetable juices

Korea 2011 Citrus juices

High Pressure ProcessingCommercial juice products

Source: Hiperbaric


“Starbucks Acquires Evolution Fresh to

Enter Wellness Space

With this acquisition, Starbucks will

reinvent the $1.6 billion super-premium

juice segment, its significant next step in

entering the larger $50 billion Health and

Wellness sector”.

Press Release Nov 2011

Source: Hiperbaric

Processing coconut water in Millard (3 x Hiperbaric 420)

“WE DID IT! INTRODUCING THE

WORLD'S FIRST RTD RAW &

ORGANIC COCONUT WATER.”

Source: Hiperbaric14


DIL UHDE HPP TOLLING CENTER

1 x 350 l cold press system

1 x 150 l hot press system

200 m2 chilled storage facilities

Treatment capacity

2.200 kg/h or up to 25 t/day

High Pressure ProcessingOutlook

Pulsed Electric Field ProcessingEffects on biological tissue

Pulsed Electric FieldsPotato industry

Approx 40 machines worldwidefor tissue softening at 50 t/h

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

22

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

Pulsed Electric FieldsLine setup

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

Pulsed Electric FieldsThermal load

(Netherlands)(UK)

(Netherlands)

(UK)

SupermarketsProducers

(Netherlands)

(Germany)

(Germany)

Pulsed Electric FieldsCommercial experience

5 kW systemCapacity: 1.500 kg/h for cell disintegration

200 l/h for microbial inactivation

30 kW systemCapacity: 10.000 kg/h for cell disintegration

1.500 to 1.800 l/h for microbial inactivation

Pulsed Electric FieldsEquipment

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



Pulsed Electric Field ProcessingChamber design

Improvement of homogeneity

Shrink-on design

Field concentration chamber

DN 50

Pulsed Electric FieldsInstalled systems

2 x 1.600 l/h

Pulsed Electric FieldsInstalled systems

1 x 1.800 l/h

Nonthermal TechnologiesCase study: juice pasteurisation

Comparison of HTST, PEF and HPP for SME juice processing company

2.000 – 3.000 l/h15 – 20 juice types per week

0 50 100 150 200 250 300

HTST

PEF

HPP

Energy kJ/kg

0 10 20 30 40 50 60 70 80 90

HTST

PEF

HPP

Temperature (°C)

Nonthermal TechnologiesEnergy requirement and maximum temperature

Nonthermal technologiesCase study: overview

HSTS PEF HPH HPP

Energyrequirement

150 kJ/kg 110 kJ/kg 120 kJ/kg 280 kJ/kg

Product loss(excluding filler)

Approx. 100 per batch

Approx 55 l per batch

Approx 55 l per batch

In pack treatment

Fillingrequirement

Ultraclean Ultraclean Ultraclean Standard

Typicalprocessing costs

0,005 – 0,01 €/l 0,01 – 0,02 €/l 0,07 – 0,10 €/l 0,20 – 0,30 €/l

Nonthermal technologiesApproval

Nonthermal technologiesLife cycle analysis

FU 1 l of processed juice, scope - from farm to gate; zero values of aquatic acidification and

eutrophication excluded; 1 kPt = impact of 1 European per year

~50%

Nonthermal technologiesLife cycle analysis

Aganovic, K., Smetana, S., Grauwet, T., Toepfl, S., Mathys, A., Van Loey, A., Heinz, V. Pilot scalethermal and alternative pasteurization oftomato and watermelon juice: an energycomparison and life cycle assessment. Journal of cleaner production (submitted)

• Making use of alternatives to thermal processing allows low temperature preservation

• HPP and PEF are in commercial use in food industry

• Technique to be selected dependent on product type, packaging, throughput and commercial background

Nonthermal technologiesConclusions

nonthermal treatments of fruit and vegetable products

Science