The microbial inactivation and specific energy of a pulsed electric field treatment system are dependent on the electric field distribution and treatment time since they have opposite behaviour in relation to these parameters, featuring a problem of multi-objective optimisation. This study proposes a computational methodology capable of providing Pareto optimal solutions for these two objectives, using a coupled electrical-thermal model, solved by COMSOL, which has been integrated to a multi-objective algorithm NSGA-II implemented in MatLab. The simulations were run for a computational design of experiment with the following variables: applied voltage, treatment time and the internal electrode radius (three levels for each one). In the post-processing analysis, the Pareto curves were plotted for two typical microorganisms of grape juice: E. coli and S. aureus, providing a set of solutions in terms of the log of the survival rate versus the specific energy. The methodology enables the decision maker to select the best solution from the Pareto curves as a function of a required microbial inactivation and energy features.

References

1. 1)
  - 6. Chaturongakul, S., Kirawanich, P.: ‘Electropermeabilization responses in gram-positive and gram-negative bacteria’, J. Electrost., 2013, 71, (4), pp. 773–777.
2. 2)
  - 34. Takahashi, R.H., Vasconcelos, J., Ramírez, J.A., et al: ‘A multiobjective methodology for evaluating genetic operators’, IEEE Trans. Magn., 2003, 39, (3), pp. 1321–1324.
3. 3)
  - 27. Simion, A.I., Dobrovici, P.E., Rusu, L., et al: ‘Modeling of the thermo-physical properties of grapes juice iii. Viscosity and heat capacity’, Sci. Study Res. Chem. Chem. Eng. Biotechnol. Food Ind., 2011, 12, (4), pp. 409–420.
4. 4)
  - 15. Qin, B.L., Barbosa Canovas, G.V., Swanson, B.G., et al: ‘Continuous flow electrical treatment of flowable food products’. U.S. Patent 5,776,529, 1998.
5. 5)
  - 37. Seshadri, A.: ‘Multi-objective optimization using evolutionary algorithms (moea)’, Matlab Website.Available at http://www Mathworks.com/matlabcentral/fileexchange/10429, by, 2006, 19.
6. 6)
  - 5. Li, X., Farid, M.: ‘A review on recent development in non-conventional food sterilization technologies’, J. Food Eng., 2016, 182, pp. 33–45.
7. 7)
  - 32. Loeffler, M.J.: ‘Generation and application of high intensity pulsed electric fields’. in Raso, J. , Heinz, V., et al (Eds.): Pulsed electric fields technology for the food industry (Springer, USA, 2006), pp. 27–72.
8. 8)
  - 3. Jayaram, S., Castle, G., Margaritis, A.: ‘Kinetics of sterilization of lactobacillus brevis cells by the application of high voltage pulses’, Biotechnol. Bioeng., 1992, 40, (11), pp. 1412–1420.
9. 9)
  - 21. Knoerzer, K., Baumann, P., Buckow, R.: ‘An iterative modelling approach for improving the performance of a pulsed electric field (pef) treatment chamber’, Comput. Chem. Eng., 2012, 37, pp. 48–63.
10. 10)
  - 31. Telford, J.K.: ‘A brief introduction to design of experiments’, Johns Hopkins APL Tech. Dig., 2007, 27, (3), pp. 224–232.
11. 11)
  - 1. Jayaram, S.H.: ‘Pulsed power applied to process industry’, IEEE Ind. Appl. Mag., 2010, 16, (4), pp. 34–40.
12. 12)
  - 30. Bejan, A., Kraus, A.D.: ‘Heat transfer handbook’, vol. 1 (John Wiley & Sons, USA, 2003).
13. 13)
  - 24. Araujo, E., Lopes, I., Ramirez, J.: ‘Comparison of electrodes arrangements of a high voltage pulsed electric field system for liquid sterilization using fem coupled with multi-objective optimization’. Proc. 20th Int. Symp. on High Voltage Engineering (ISH), Buenos Aires, Argentina, 2017, pp. 1–6 (Paper ID:199).
14. 14)
  - 18. Toepfl, S., Heinz, V., Knorr, D.: ‘Applications of pulsed electric fields technology for the food industry’. in Raso, J., Heinz, V., et al (Eds.): Pulsed electric fields technology for the food industry (Springer, USA, 2006), pp. 197–221.
15. 15)
  - 11. Huang, K., Wang, J.: ‘Designs of pulsed electric fields treatment chambers for liquid foods pasteurization process: a review’, J. Food Eng., 2009, 95, (2), pp. 227–239.
16. 16)
  - 26. Simion, A.I., Grigora, S. C., Rusu, L., et al: ‘Modeling of the thermo-physical properties of grapes juice ii. Boiling point and density’, Sci. Study Res. Chem. Chem. Eng. Biotechnol. Food Ind., 2009, 10, (4), pp. 365–374.
17. 17)
  - 16. Alvarez, I., Condon, S., Raso, J.: ‘Microbial inactivation by pulsed electric fields’, in Raso, J., Heinz, V., et al (Eds.): Pulsed electric fields technology for the food industry (Springer, USA, 2006), pp. 97–129.
18. 18)
  - 29. Gerlach, D., Alleborn, N., Baars, A., et al: ‘Numerical simulations of pulsed electric fields for food preservation: a review’, Innovative Food Sci. Emerging Technol., 2008, 9, (4), pp. 408–417.
19. 19)
  - 23. Jaeger, H., Meneses, N., Knorr, D.: ‘Impact of PEF treatment inhomogeneity such as electric field distribution, flow characteristics and temperature effects on the inactivation of E. coli and milk alkaline phosphatase’, Innovative Food Sci. Emerging Technol., 2009, 10, (4), pp. 470–480.
20. 20)
  - 39. Schroeder, S., Buckow, R., Knoerzer, K.: ‘Numerical simulation of pulsed electric field (pef) processing for chamber design and optimization’. 7th Proc. Int. Conf. on CFD in the Minerads and Process Industries CSIRO, Australia, December 2009, pp. 1–6.
21. 21)
  - 19. Toepfl, S., Heinz, V., Knorr, D.: ‘High intensity pulsed electric fields applied for food preservation’, Chem. Eng. Process., 2007, 46, (6), pp. 537–546.
22. 22)
  - 12. Buckow, R., Ng, S., Toepfl, S.: ‘Pulsed electric field processing of orange juice: a review on microbial, enzymatic, nutritional, and sensory quality and stability’, Compr. Rev. Food Sci. Food Saf., 2013, 12, (5), pp. 455–467.
23. 23)
  - 36. Batista, L.S., Campelo, F., Guimarães, F.G., et al: ‘Pareto cone-dominance: improving convergence and diversity in multiobjective evolutionary algorithms’. Proc. 6th Int. Conf. on Evolutionary Multi-Criterion Optimization, Ouro Preto, Brazil, 2011, pp. 76–90.
24. 24)
  - 4. Uchida, S., Houjo, M., Tochikubo, F.: ‘Efficient sterilization of bacteria by pulse electric field in micro-gap’, J. Electrost., 2008, 66, (7-8), pp. 427–431.
25. 25)
  - 25. Simion, A., Dobrovici, P., Rusu, L., et al: ‘Modeling of the thermo-physical properties of grapes juice i. Thermal conductivity and thermal diffusivity’, Ann. Food Sci. Technol., 2009, 10, (2), pp. 363–368.
26. 26)
  - 13. Qin, B., Zhang, Q., Barbosa Cánovas, G., et al: ‘Pulsed electric field treatment chamber design for liquid food pasteurization using a finite element method’, Trans. ASAE, 1995, 38, (2), pp. 557–565.
27. 27)
  - 35. Deb, K., Pratap, A., Agarwal, S., et al: ‘A fast and elitist multiobjective genetic algorithm: Nsga-ii’, IEEE Trans. Evol. Comput., 2002, 6, (2), pp. 182–197.
28. 28)
  - 14. Huang, K., Yu, L., Wang, W., et al: ‘Comparing the pulsed electric field resistance of the microorganisms in grape juice: application of the weibull model’, Food Control, 2014, 35, (1), pp. 241–251.
29. 29)
  - 8. Gaynor, P., Bodger, P.: ‘Balloon model of biological cell electropermeabilisation in relation to the radius dependence of membrane dielectric breakdown’, IEE Proc., Sci. Meas. Technol., 1995, 142, (4), pp. 277–282.
30. 30)
  - 10. Buckow, R., Baumann, P., Schroeder, S., et al: ‘Effect of dimensions and geometry of co-field and co-linear pulsed electric field treatment chambers on electric field strength and energy utilisation’, J. Food Eng., 2011, 105, (3), pp. 545–556.
31. 31)
  - 28. Huang, K., Tian, H., Gai, L., et al: ‘A review of kinetic models for inactivating microorganisms and enzymes by pulsed electric field processing’, J. Food Eng., 2012, 111, (2), pp. 191–207.
32. 32)
  - 38. Buckow, R., Schroeder, S., Berres, P., et al: ‘Simulation and evaluation of pilot-scale pulsed electric field (pef) processing’, J. Food Eng., 2010, 101, (1), pp. 67–77.
33. 33)
  - 20. Saldaña, G., Puértolas, E., Álvarez, I., et al: ‘Evaluation of a static treatment chamber to investigate kinetics of microbial inactivation by pulsed electric fields at different temperatures at quasi-isothermal conditions’, J. Food Eng., 2010, 100, (2), pp. 349–356.
34. 34)
  - 7. Ohshima, T., Okuyama, K., Sato, M.: ‘Effect of culture temperature on high-voltage pulse sterilization of escherichia coli’, J. Electrost., 2002, 55, (3-4), pp. 227–235.
35. 35)
  - 22. Huang, K., Yu, L., Gai, L., et al: ‘Coupled simulations in colinear and coaxial continuous pulsed electric field treatment chambers’, Trans. ASABE, 2013, 56, (4), pp. 1473–1484.
36. 36)
  - 2. Quass, D.: ‘Pulsed electric field processing in the food industry’, A Status Report on PEF, CR-109742, Electric Power Research Institute, Palo Alto, CA, 1997.
37. 37)
  - 9. Álvarez, I., Pagán, R., Raso, J., et al: ‘Environmental factors influencing the inactivation of listeria monocytogenes by pulsed electric fields’, Lett. Appl. Microbiol., 2002, 35, (6), pp. 489–493.
38. 38)
  - 33. Kotnik, T., Pucihar, G., Reberšek, M., et al: ‘Role of pulse shape in cell membrane electropermeabilization’, Biochim. Biophys. Acta Biomembr.2003, 1614, (2), pp. 193–200.
39. 39)
  - 17. Morales-de La Peña, M., Elez Martínez, P., Martín Belloso, O.: ‘Food preservation by pulsed electric fields: an engineering perspective’, Food Eng. Rev., 2011, 3, (2), pp. 94–107.

Computational modelling approach for the optimisation of a pulsed electric field system for liquid foods

References

Related content