Moderate intensity Pulsed Electric Fields (PEF) as alternative mild preservation technology for fruit juice

R.A.H. Timmermans*, H.C. Mastwijk, L.B.J.M. Berendsen, A.L. Nederhoff, A.M. Matser, M.A.J.S. Van Boekel, M.N. Nierop Groot

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

5 Citations (Scopus)

Abstract

Moderate intensity Pulsed Electric Fields (PEF) was studied for microbial inactivation as an alternative to high intensity PEF or to classical thermal pasteurization. The process is characterized by the application of electric pulses, allowing an increase of the product temperature by the ohmic heat generated by the pulses. A systematic evaluation of the effect of parameters electric field strength (E) and pulse width (τ) on the inactivation of Escherichia coli, Listeria monocytogenes, Lactobacillus plantarum, Salmonella Senftenberg and Saccharomyces cerevisiae in orange juice was carried out in a continuous flow system. A wide range of conditions was evaluated, and both E and τ were shown to be important in the efficacy to inactivate micro-organisms. Remarkably, PEF conditions at E = 2.7 kV/cm and τ = 15–1000 μs showed to be more effective in microbial inactivation than at E = 10 kV/cm and τ = 2 μs. Inactivation kinetics of the tested PEF conditions were compared to an equivalent thermal process to disentangle non-thermal effects (electroporation) from thermal effects responsible for the microbial inactivation. At standard high intensity PEF treatment a non-thermal inactivation at E = 20 kV/cm and τ = 2 μs pulses was observed and attributed to electroporation. Non-thermal effects could also be resolved with moderate intensity PEF at E = 2.7 kV/cm and pulse width between τ = 15–1000 μs. Microbial inactivation at these moderate intensity PEF conditions was studied in more detail at different pH and medium conductivity for E. coli and L. monocytogenes in watermelon juice and coconut water. Under moderate intensity PEF conditions the effectiveness of treatment was independent of pH for all evaluated matrices in the pH range of 3.8–6.0, whereas under high intensity PEF conditions the pH of the product is a critical factor for microbial inactivation. This suggests that the inactivation proceeds through a different mechanism at moderate intensity PEF, and speculations for this mechanism are presented. In conclusion, moderate intensity PEF conditions at E = 2.7 kV/cm and pulse width of 15–1000 μs has potential for industrial processing for the preservation of fruit juices and pH neutral liquid food products.

Original languageEnglish
Pages (from-to)63-73
Number of pages11
JournalInternational Journal of Food Microbiology
Volume298
DOIs
Publication statusPublished - 2 Jun 2019

Fingerprint

Microbial Viability
pulsed electric fields
fruit juices
inactivation
Technology
Hot Temperature
Electroporation
Listeria monocytogenes
Citrullus
Escherichia coli
Pasteurization
Lactobacillus plantarum
Cocos
heat
electroporation
Salmonella
Saccharomyces cerevisiae
Fruit and Vegetable Juices
Salmonella Senftenberg
Food

Keywords

  • Electric field strength
  • Microbiology
  • Ohmic heating
  • Preservation
  • Pulse width
  • Thermal reference

Cite this

@article{a16fe873649e40a09cf7a2c4eac10f44,
title = "Moderate intensity Pulsed Electric Fields (PEF) as alternative mild preservation technology for fruit juice",
abstract = "Moderate intensity Pulsed Electric Fields (PEF) was studied for microbial inactivation as an alternative to high intensity PEF or to classical thermal pasteurization. The process is characterized by the application of electric pulses, allowing an increase of the product temperature by the ohmic heat generated by the pulses. A systematic evaluation of the effect of parameters electric field strength (E) and pulse width (τ) on the inactivation of Escherichia coli, Listeria monocytogenes, Lactobacillus plantarum, Salmonella Senftenberg and Saccharomyces cerevisiae in orange juice was carried out in a continuous flow system. A wide range of conditions was evaluated, and both E and τ were shown to be important in the efficacy to inactivate micro-organisms. Remarkably, PEF conditions at E = 2.7 kV/cm and τ = 15–1000 μs showed to be more effective in microbial inactivation than at E = 10 kV/cm and τ = 2 μs. Inactivation kinetics of the tested PEF conditions were compared to an equivalent thermal process to disentangle non-thermal effects (electroporation) from thermal effects responsible for the microbial inactivation. At standard high intensity PEF treatment a non-thermal inactivation at E = 20 kV/cm and τ = 2 μs pulses was observed and attributed to electroporation. Non-thermal effects could also be resolved with moderate intensity PEF at E = 2.7 kV/cm and pulse width between τ = 15–1000 μs. Microbial inactivation at these moderate intensity PEF conditions was studied in more detail at different pH and medium conductivity for E. coli and L. monocytogenes in watermelon juice and coconut water. Under moderate intensity PEF conditions the effectiveness of treatment was independent of pH for all evaluated matrices in the pH range of 3.8–6.0, whereas under high intensity PEF conditions the pH of the product is a critical factor for microbial inactivation. This suggests that the inactivation proceeds through a different mechanism at moderate intensity PEF, and speculations for this mechanism are presented. In conclusion, moderate intensity PEF conditions at E = 2.7 kV/cm and pulse width of 15–1000 μs has potential for industrial processing for the preservation of fruit juices and pH neutral liquid food products.",
keywords = "Electric field strength, Microbiology, Ohmic heating, Preservation, Pulse width, Thermal reference",
author = "R.A.H. Timmermans and H.C. Mastwijk and L.B.J.M. Berendsen and A.L. Nederhoff and A.M. Matser and {Van Boekel}, M.A.J.S. and {Nierop Groot}, M.N.",
year = "2019",
month = "6",
day = "2",
doi = "10.1016/j.ijfoodmicro.2019.02.015",
language = "English",
volume = "298",
pages = "63--73",
journal = "International Journal of Food Microbiology",
issn = "0168-1605",
publisher = "Elsevier",

}

Moderate intensity Pulsed Electric Fields (PEF) as alternative mild preservation technology for fruit juice. / Timmermans, R.A.H.; Mastwijk, H.C.; Berendsen, L.B.J.M.; Nederhoff, A.L.; Matser, A.M.; Van Boekel, M.A.J.S.; Nierop Groot, M.N.

In: International Journal of Food Microbiology, Vol. 298, 02.06.2019, p. 63-73.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Moderate intensity Pulsed Electric Fields (PEF) as alternative mild preservation technology for fruit juice

AU - Timmermans, R.A.H.

AU - Mastwijk, H.C.

AU - Berendsen, L.B.J.M.

AU - Nederhoff, A.L.

AU - Matser, A.M.

AU - Van Boekel, M.A.J.S.

AU - Nierop Groot, M.N.

PY - 2019/6/2

Y1 - 2019/6/2

N2 - Moderate intensity Pulsed Electric Fields (PEF) was studied for microbial inactivation as an alternative to high intensity PEF or to classical thermal pasteurization. The process is characterized by the application of electric pulses, allowing an increase of the product temperature by the ohmic heat generated by the pulses. A systematic evaluation of the effect of parameters electric field strength (E) and pulse width (τ) on the inactivation of Escherichia coli, Listeria monocytogenes, Lactobacillus plantarum, Salmonella Senftenberg and Saccharomyces cerevisiae in orange juice was carried out in a continuous flow system. A wide range of conditions was evaluated, and both E and τ were shown to be important in the efficacy to inactivate micro-organisms. Remarkably, PEF conditions at E = 2.7 kV/cm and τ = 15–1000 μs showed to be more effective in microbial inactivation than at E = 10 kV/cm and τ = 2 μs. Inactivation kinetics of the tested PEF conditions were compared to an equivalent thermal process to disentangle non-thermal effects (electroporation) from thermal effects responsible for the microbial inactivation. At standard high intensity PEF treatment a non-thermal inactivation at E = 20 kV/cm and τ = 2 μs pulses was observed and attributed to electroporation. Non-thermal effects could also be resolved with moderate intensity PEF at E = 2.7 kV/cm and pulse width between τ = 15–1000 μs. Microbial inactivation at these moderate intensity PEF conditions was studied in more detail at different pH and medium conductivity for E. coli and L. monocytogenes in watermelon juice and coconut water. Under moderate intensity PEF conditions the effectiveness of treatment was independent of pH for all evaluated matrices in the pH range of 3.8–6.0, whereas under high intensity PEF conditions the pH of the product is a critical factor for microbial inactivation. This suggests that the inactivation proceeds through a different mechanism at moderate intensity PEF, and speculations for this mechanism are presented. In conclusion, moderate intensity PEF conditions at E = 2.7 kV/cm and pulse width of 15–1000 μs has potential for industrial processing for the preservation of fruit juices and pH neutral liquid food products.

AB - Moderate intensity Pulsed Electric Fields (PEF) was studied for microbial inactivation as an alternative to high intensity PEF or to classical thermal pasteurization. The process is characterized by the application of electric pulses, allowing an increase of the product temperature by the ohmic heat generated by the pulses. A systematic evaluation of the effect of parameters electric field strength (E) and pulse width (τ) on the inactivation of Escherichia coli, Listeria monocytogenes, Lactobacillus plantarum, Salmonella Senftenberg and Saccharomyces cerevisiae in orange juice was carried out in a continuous flow system. A wide range of conditions was evaluated, and both E and τ were shown to be important in the efficacy to inactivate micro-organisms. Remarkably, PEF conditions at E = 2.7 kV/cm and τ = 15–1000 μs showed to be more effective in microbial inactivation than at E = 10 kV/cm and τ = 2 μs. Inactivation kinetics of the tested PEF conditions were compared to an equivalent thermal process to disentangle non-thermal effects (electroporation) from thermal effects responsible for the microbial inactivation. At standard high intensity PEF treatment a non-thermal inactivation at E = 20 kV/cm and τ = 2 μs pulses was observed and attributed to electroporation. Non-thermal effects could also be resolved with moderate intensity PEF at E = 2.7 kV/cm and pulse width between τ = 15–1000 μs. Microbial inactivation at these moderate intensity PEF conditions was studied in more detail at different pH and medium conductivity for E. coli and L. monocytogenes in watermelon juice and coconut water. Under moderate intensity PEF conditions the effectiveness of treatment was independent of pH for all evaluated matrices in the pH range of 3.8–6.0, whereas under high intensity PEF conditions the pH of the product is a critical factor for microbial inactivation. This suggests that the inactivation proceeds through a different mechanism at moderate intensity PEF, and speculations for this mechanism are presented. In conclusion, moderate intensity PEF conditions at E = 2.7 kV/cm and pulse width of 15–1000 μs has potential for industrial processing for the preservation of fruit juices and pH neutral liquid food products.

KW - Electric field strength

KW - Microbiology

KW - Ohmic heating

KW - Preservation

KW - Pulse width

KW - Thermal reference

U2 - 10.1016/j.ijfoodmicro.2019.02.015

DO - 10.1016/j.ijfoodmicro.2019.02.015

M3 - Article

VL - 298

SP - 63

EP - 73

JO - International Journal of Food Microbiology

JF - International Journal of Food Microbiology

SN - 0168-1605

ER -