Pulsed electric field technique is commercially used in food industries to preserve fruit juice without effecting its nutritional quality.

1. BOTTLE CONTAINING FOOD
AND NUTRIENTS
Well balanced diet
rich in fruits and
vegetables serves
health and decrease
health risk............

2. Consumption of
juice have
emphasis
importance in our
diet

3. Non thermal
food
Healthy
food
Fres
h
food
HPP
Irradiation
Ultrasonic
processing
PEF

5. KITTUR RANI CHANNAMMA COLLEGE OF HORTICULTURE,
ARABHAVI
SEMINAR-II
Preservation of juice by pulsed electric
field
ARCHANA T JANAMATTI
UHS13PGM341
PHT DEPARTMENT

6. Basic concept of PEF
• Non thermal food preservation method
• Based on the use of electric fields
• Extend the shelf life of food products
• Preserve quality attributes
• Microbiological safety of the food
Toepfl et al., 2005

7. • It involves the application of high voltage
(typically 20 – 80 kV/ Cm) in short (1-10 µs)
pulses ( up to 1000 HZ) to foods between two
electrodes
• Total treatment time < 1s (generally)
• Conducted at ambient, sub – ambient, or
slightly above ambient temperature
What is pulsed electric field ?
Toepfl et al., 2005

8. The principle of
PEF
ELECTROPHORATION
Exposing a biological cell (plant, animal
and microbial) to a high intensity electric
field (kV/cm) in form of very short
pulses (μs to ms) induces the formation
of temporary or permanent pores on the
cell membrane.
Toepfl et al., 2005

9. ELECTROPHORATION
E < EC
E > Ec
E >> Ec

10. How this can be exploited commercially ???
Area 1: Preservation – microbial inactivation
e.g. Preservation of high quality beverages
Area 2 : Cell disintegration – less difficulty vs. Above
e.g. Extraction of juices and ingredients
Dehydration of fruits and vegetables (↑ drying rate)
Toepfl et al., 2005

11. Mile stones of pulsed electric field
1920 1950 1960 1968 1980 1988 2003 2007
ELECTROPURE
ELECTROHYDRAULIC
TREATMENT
DOEVENSPECK-PEF
SALE&HAMILTON–PEFON
MICROBES
GENETRANSFER
PATENTTOKRUP–ELCRACK,
ELSTERIL
CELLPERMIABILIZATION
GENESISJUICEPRODUCTION
20001960
Zhang et al., 2008
20201970

12. 0
20
40
60
80
100
120
140
160
PEF
PUBLICATIONSPER5YRSHistory of PEF
Scientific publications (web of knowledge)
Relevant publications of PEF research work as cited in Food Science and Technology
Abstracts (FSTA) Database from 1987 to 2011.
Heinz et al., 2007

13. 0
50
100
150
200
250
300
HPP
PEF
US
UV
PUBLICATIONSPER5YRSScientific publications vs. Other technologies (web of
knowledge)
Relevant publications of PEF research work as cited in Food Science and Technology
Abstracts (FSTA) Database from 1987 to 2011.
Minimally processed food -
concept
Heinz et al., 2007

14. The main components of PEF
Pulse generating
system
Treatment chamber
Fluid handling system
Control and
monitoring device

15. PUSLE GENERATION SYSTEM
Generation of DC voltage at the
required intensity by a power
supply
Storage of electrical energy in a capacitor
or of group of capacitors
Release of high voltage in the form of pulse (pulse width
and shape) through pulse forming network
Barbosa et al., 1998

16. Barbosa et al., 1998IMPUSLE GENERATION
SYSTEM
ON ON/ OFF
EXPONENTIAL DECAY
PULSE SQUARE PULSE

17. TREATMENT CHAMBER
Electrode
Electrode
Barbosa et al., 1998

18. TECHNICAL
FACTORS
Electric field
intensity
Treatment time
Pulse
Characteristics
BIOLOGICAL
FACTORS
Size and shape of micro
organisms
Physiological state of
microorganisms
FACTORS OF THE
PRODUCT
Composition
Factors vs. Microbial
inactivation
Widt
h
Shape
Polarization Bipolar
Monopolar
Yeast
Gram –ve bacteria
Exponential phase
Vegetative cells
Barbosa et al., 1998

19. FACTORS OF THE
PRODUCT
Composition
Factors vs. Microbial
inactivation
Ionic strength
Conductivity
pH
Air bubbles
Solid/ fluid
Fat / carbohydrate
Barbosa et al., 1998

20. Application of PEF
 Pasteurization of foods such as juices, milk, yogurt, soups, and liquid eggs
 Cause the formation of large, permanent pore in cellular tissues, which can
be used to improve juice yield
 Plant oil extraction
Barbosa et al., 1998

21. Application of PEF
 Induce increase in mass and heat transfer and enhance drying process
 Enhance extraction of sugars and other cellular content from plant cells,
such as sugar beets
 For heat-sensitive liquid foods where thermal pasteurization is not an
option (due to flavour, texture, or colour changes), PEF treatment would be
advantageous
Barbosa et al., 1998

22. Case studies

23. Inactivation of Lactobacillus brevis in orange
juice by high-intensity pulsed electric fields

24. Objective: To investigate the inactivation of L. brevis suspended in
the orange juice by HIPEF
Treatment details:
Lactobacillus brevis strain – CECT 216
HIPEF:
Continuous flow bench scale system
Square wave pulses
Electric field strength – 5, 15,20,30,35 kV/cm
Treatment time – 50, 150, 300, 600 and 1000 µs
Pulse width – 1, 2, 4, 8 and 10 µs
Frequency – 50, 150, 200, 250 and 300 Hz
Polarity – monopolar and bipolar
Pedro et al., 2005

25. Pedro et al., 2005
Figure 5: Inactivation of L. brevis in orange juice exposed to mono- (A), and bipolar (B) HIPEF
(mean7SD, n ¼ 4). Pulse frequency=200 Hz; pulse width=4 µs. Square pulses. E, electric field
strength. Thermal treatment=90± 1 ⁰C/1 min (horizontal line)

26. Figure 6: Effect of pulse frequency on the survival fraction of L. brevis in orange juice
exposed to HIPEF (mean7SD, n ¼ 4). S, survival fraction; f, pulse frequency. Electric
field strength=30 kV/cm; treatment time=300 µs; polarity mode=bipolar; pulse
width=4 µs. Square pulses. The plotted line corresponds to a linear model fit (Eq. (1)).
R2, determination coefficient; significance level, p ¼ 0:05
Pedro et al., 2005

27. Figure 7: Effect of pulse width on the survival fraction of L. brevis in orange juice exposed
to HIPEF (mean7SD, n ¼ 4). S, survival fraction; t; pulse width. Electric field strength=30
kV/cm; treatment time=300 µs; polarity mode=bipolar; pulse frequency=200 Hz. Square
pulses. The plotted line corresponds to a linear model fit (Eq. (2)). R2, determination
coefficient; significance level, p ¼ 0:05.
Pedro et al., 2005

28. Figure 8: SEMs of untreated and HIPEF-treated cells of L. brevis in orange
juice. (A) Untreated (2.000); (B) treated (2.000) at a field strength of 35
kV/cm for 1000 ms using pulses of 4 µs width at 200 Hz frequency applied in
bipolar mode. Arrows indicate damaged cells or cells with rough surface or
merging cells.
Pedro et al., 2005

29. Figure 9: TEMs of untreated and HIPEF-treated cells of L. brevis in orange
juice. (A) Untreated (20.000); (B) treated (25.000) at a field strength of 35
kV/cm for 1000 µs using pulses of 4 µs width at 200 Hz frequency applied in
bipolar mode. Arrows indicate the ruptured cell wall or cytoplasmatic
material that has leaked out of
the cells.
Pedro et al., 2005

30. Flavour retention and related enzyme
activities during storage of strawberry juices
processed by high-intensity pulsed electric
fields or heat

31. Objective: The aim of the present work was to study and compare the retention
of volatile compounds contributing to the strawberry characteristic aroma during
the commercial shelf-life of HIPEF and thermally-processed strawberry juices. In
addition, this study evaluated the effect of HIPEF and thermal processing on
enzyme activities involved in flavour synthesis.
Treatment setup
HIPEF
 35kV /cm for1700 µs
Square wave pulse of 4µs
Pulse frequency of 100 Hz in a bipolar mode
Thermal treatment (TT)- 90 ⁰C for 30 s and 60 s
Ingrid et al., 2009

32. Figure 1: Effects of HIPEF and thermal treatments, 90 ⁰C for
60 s (TT 60 s) or for 30s (TT 30 s) on residual lipoxygenase
(RALOX) activity (mean ± SD) of strawberry juice throughout
storage at 4 ⁰C
Ingrid et al., 2009

33. Figure 2: Effects of HIPEF and thermal treatments, 90 ⁰C for 60 s
(TT 60 s) or for 30 s (TT 30 s) on residual β-glucosidase ( RAβ-LGUC )
activity (mean ± SD) of strawberry juice throughout storage at 4 ⁰C
Ingrid et al., 2009

34. Table 1: Effects of HIPEF treatment and thermal treatments, 90 ⁰C for 60 s (TT 60 s) or for 30 s (TT 30
s) on the retention of hexanal, 1-butanol, linalool and DMHF (mean ± SD) (n = 3) of strawberry juice
throughout storage at 4 ⁰C Ingrid et al., 2009

35. Carotenoid and phenolic profile of tomato
juices processed by high intensity pulsed
electric fields compared with conventional
thermal treatments

36. Objective: The aim of the present work was to evaluate and compare
the effects of HIPEF processing and heat pasteurisation on individual
carotenoids and phenolic compounds of tomato juice
Treatment details:
1. Pulsed electric field treatment
35kV/cm for 1500 µs
Bipolar square wave
Pulse of 4 µs with frequency of 100 Hz
2. Thermal treatment
90 ⁰C for 60 s
90 ⁰C for 30 s
Isabel et al., 2009

37. Table 2: Effects of high-intensity pulsed electric field and heat pasteurisation on carotenoids
of tomato juice throughout storage at 4 ⁰C Isabel et al., 2009

38. Table 3:Effects of high-intensity pulsed electric fields and heat pasteurisation on phenolic
compounds of tomato juice throughout storage at 4⁰C Isabel et al., 2009

39. Thermal and pulsed electric fields pasteurization
of apple juice: Effects on physicochemical
properties and flavour compounds

40. Objective: The aim was to investigate the impact of PEF and HTST
pasteurization of apple juice on retention of volatile compounds
which are responsible for characteristic aroma and tasteful flavour
Treatment details:
Golden delicious apple variety
PEF treatment: 35 kV/ cm for 1200 µs with 4 µs
bipolar pulses
Heat pasteurization: 90 ⁰C for 30 s
Rosas et al., 2007

41. Experimental setup used for heat pasteurization of apple juice
Rosas et al., 2007

42. Diagram of pulsed electric field operation
Rosas et al., 2007

43. Figure 3: Effect of PEF and HTST treatment method on total phenol
compounds of pasteurized apple juice
Rosas et al., 2007

44. Rosas et al., 2007
Table 4: Percentage of volatiles losses, compared with untreated
sample, in apple juice treated by two methods

46. Objective: The aim of this paper is to evaluate the effect of PEF
processing on the bioactive compounds and browning activity
in comparison with thermally treated Embilica officinalis juice
Vasudha et al., 2013
Thermal treatment : 90 ⁰C for 60 s
Storage : 20 ⁰C for 6 weeks
Rectangular monopolar pulse
Pulse width - 4µs
Electric field strength – 24 k V/ cm
Pulse frequency – 1 Hz
Treatment details:
Pulsed electric field treatment

47. Figure 4: Effects of PEF processing on total polyphenolic content of
Emblica officinalis Juice
Vasudha et al., 2013

48. Vasudha et al., 2013
Figure 4: Effects of PEF on non enzymatic browning index of Emblica
officinalis juice

49. Vasudha et al., 2013
Table 5: Effect of PEF and thermal treatment on formation of 5-hydroxymethyl-2-
furfural and on DPPH

51. Objective: The purpose of this study was to evaluate the microbiological
shelf life of apple, pear, tomato, strawberry and orange juice treated by
HIPEF with or without added citric acid or cinnamon bark oil.
Treatment details:
Apple ( Malus domestica Borkh var. “Fuji”)
Pear ( Pyrus communis L. var. “Flor de invierno”)
Tomato ( Solanum lycopersicum var. “Roma”)
Jonathan et al., 2012
Strawberry (Fragaria spp. var. “Camarosa”)
Orange (Citrus sinensis L. var. “Valencia”)

52. Treatment conditions
Jonathan et al., 2012

53. Table 7 : Estimated values of the Gompertz’s parameters of mesophilic, mold and yeast and
psychrophilic populations of HIPEF-treated fruit juices stored at 5 ⁰C
Table 6: Estimated values of the Gompertz’s parameters of mesophilic, mold and yeast, and
psychrophilic populations of untreated fruit juices stored at 5 ⁰C
Jonathan et al., 2012

54. Table 8: Microbiological shelf life of fruit juices under different processing conditions and
stored at 5 ⁰C Jonathan et al., 2012

55. Present status
Today about 25 research groups working in this area world wide
Though the technology has been explored almost 50 years ago,
only a limited amount of technical or industrial scale prototypes
or commercial applications available at present
Manufacturers
Pure pulse technologies, USA
DIL (German institute of food
technology)
The first commercial scale
continuous PEF system is-
The Ohio State University
Department of Food Science and
Technology.
Heinz et al., 2007

56. Availability of PEF facilities........................
Heinz et al., 2007

57. Cost of technology
 US $250,000 to 500,00
 The PEF processing would add only $0.02 to $0.07/L to final
food costs.
 A commercial-scale PEF system can process between 1,000
and 5,000 litres of liquid foods per hour and this equipment is
scalable.
Heinz et al., 2007

58. 0
20
40
60
80
100
120
10 100 1000
1
Thermal
pasteurization
Thermal
sterilization
HPP
Irradiation
PEF
MaximumTemperature(⁰C)
Estimated total costs (€/ t)
Comparision of techniques ( Cost vs Temp)
Heinz et al., 2007

59. Comparision between the PEF and Thermal
Processing
PULSED ELECTRIC FIELD THERMAL PROCESSING
It is maintain the color, flavour &
aroma of the food.
It doesn't maintain the color, flavour
& aroma of the food.
Initial cost is more but running cost
is less.
Initial cost is less but running cost is
more.
Less time required. More time required.
Gauri et al., 2000

60. Plus Less treatment time
 Low treatment temperature
 Substitute for conventional heat pasteurization
 Increase shelf life and maintain food safety with low
processing costs
 PEF inactivates vegetative micro-organisms including
yeasts, spoilage micro-organisms and pathogens.
Minus
 High capital cost
 Effective for the inactivation of vegetative bacteria only
 Spores, with their tough protective coats are not destroyed
 Refrigeration is required to extend shelf-life
 PEF is a continuous processing method, which is not
suitable for solid food products that are not pumpable
 PEF processing is restricted to food products with no air
bubbles and with low electrical conductivity
Gauri et al., 2000

61. TREATMENT CHAMBER
COOLING / HEATING SYSTEM
RAW PRODUCT
FINAL PRODUCT
PEF EQUIPMENT

63. TREATMENT CHAMBER

64.  Many possible project development designs that need to be focused
on the better understanding of this technology
 There are many technical issues that need to be addressed
 To ensure food safety, a risk assessment is required that deals with
chemical safety of PEF treated products in relation to public health
future
aspects..............................
Based on theoretical considerations and calculations, taking
into account field strength, current, time, polarity and
chemical composition of food products, the FDA
decided that there is no objection to PEF treatment of
food for preservation purposes

65. Conclusion
SL.
NO
JUICE PROCESSING
CONDITION
PURPOSE
1. STRAWBERRY 35 kV/ cm for 1700 µs Retain the volatile compound
and enzyme activities involved
in flavour synthesis
2. TOMATO 35 kV/ cm for 1500 µs Maintain the total carotenoid and
phenolic content of juice
3. APPLE 35 kV/ cm for 1200 µs Reduce volatiles losses and
maintain greater total phenolic
content
4. AONLA(Embelica
officinalis )
24 kV/cm for 500 µs Retain bioactive compounds and
to reduce the browning activity
5. ORANGE 35 kV/ cm for 1000 µs To inactivate lactobacillus brevis
6. APPLE, PEAR
AND TOMATO
35 kV/cm for 1575, 1600,
1000 respectively
To inactivate microbes and to
maintain sensory properties

66. PEF technology offers potential alternatives
to the food industry to accomplish
preservation process with high quality , safe
and nutritious food.

67. • H:My Movie.mp4

68. THANK YOU
Thank
youARCHANA T JANAMATTI
UHS13PGM341
PHT DEPARTMENT