Liquid sterilization using intense electrical pulses combined with thermal post-treatment

Kajiwara, Taiga; Oide, T.; Katsuki, S.; Sakugawa, Takashi; Akiyama, H.

doi:10.1109/ipmhvc.2014.7287205

Cited by 7 publications

(6 citation statements)

References 12 publications

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“…In order to improve inactivation effect, PEF is combined with other methods, for example, addition of natural bacteriostatic agents or heating . We, too, achieved 7‐log reduction of Enterobacter (gram‐negative) in aqueous solution of carboxymethyl cellulose (CMC) by combining ultrahigh field of 50 kV/cm with heating below 55 °C .…”

Section: Introductionmentioning

confidence: 99%

Low‐Temperature Pasteurization of Liquid Whole Egg using Intense Pulsed Electric Fields

Baba

Kajiwara

Watanabe

et al. 2017

Elect Comm in Japan

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SUMMARY This paper describes the pasteurization of liquid whole egg (LWE) using intense pulsed electric fields (PEF) combined with mild heat. Four kinds of liquids as solvents including carboxymethyl cellulose (CMC) solution, CMC solution with adding lipoproteins extracted from LWE (CMC+), LWE, and centrifuged LWE for reducing lipoproteins (LWE−) were compared for the effectiveness of the PEF pasteurization. The liquids including Enterobacter aerogenes (107 /mL) were subjected to a number of PEF with an amplitude of 30 kV/cm or 50 kV/cm. Pre‐ and post‐PEF thermal treatments with a temperature below 55 °C were used to enhance the killing effect. Our experiments show that the bacteria logarithmic reduction ratio of the pasteurization using 30 kV/cm PEF for CMC, CMC+, LWE, and LWE− were 6.6, 2.4, 1.4, and 1.6, respectively, whereas the reduction ratios were all more than 6 when the increased field of 50 kV/cm. Only bacteria in CMC solution were effectively killed compared to other liquids, which include lipoproteins, more or less. Numerical analysis of the electric field indicates the presence of lipoproteins in the vicinity of bacteria lessens the bacterial membrane potential, which results in weakening the killing effect.

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Section: Introductionmentioning

confidence: 99%

Low‐Temperature Pasteurization of Liquid Whole Egg using Intense Pulsed Electric Fields

Baba

Kajiwara

Watanabe

et al. 2017

Elect Comm in Japan

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“…For example, treatment of fresh apple juice with the combination of PEF + UV or UV + PEF revealed greater microbial inactivation (6.2 and 7.1 log cycles for PEF + UV and UV + PEF, respectively) than either PEF (5.4 log) and UV (2.2 log), respectively (Noci et al, 2008). Electric field treatment alone or in combination with heat treatment induced microbial inactivation in that no reduction in the number of E. coli was reported with heat treatment at 50°C alone but PEF + 50°C treatment revealed a 1.7 log reduction (Kajiwara et al, 2014) as it was reported that PEF exhibits synergistic effect with moderate temperature (Jaeger et al, 2010; Riener et al, 2008).…”

Section: Resultsmentioning

confidence: 99%

Processing and preservation of apple juice by pulsed electric fields combined with cinnamon essential oils: Exploring the effect of synergism

Akdemir Evrendilek,

Karaoğuz Turgut

2023

Journal of Food Safety

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Apple juice samples were treated by pulsed electric field (PEF) alone and in combination with cinnamon essential oils (CEO) at 0.0005, 0.003, and 0.06 μL mL−1 concentrations as a function of treatment time. Results revealed 11 different compounds with the highest concentrations of 44.79% 3‐propenal 3‐phenyl, 34.98% trans‐cinnamaldehyde, and 10.18% 4‐propenal 3‐phenyl in CEO. pH and total soluble solids of the apple juice samples significantly decreased; whereas total phenolic substance content of the samples significantly increased by added CEO. The same process parameters caused 3.26 ± 0.19 and 3.83 ± 0.16 log reductions on TAMB and TMY, revealing no detectable numbers after PEF treatment. Similarly, maximum 5.13 and 3.87 log reductions on Escherichia coli O157:H7 and Listeria monocytogenes were obtained on 0.06 μL mL−1 CEO added samples treated after 604 μs. Moreover, increased CEO concentration, when treatment time was constant, caused significantly more microbial inactivation. Increase in treatment time resulted in an incline on ΔH of the samples. Response optimization revealed that 604 μs treatment time and 0.06 μL mL−1 concentration were the optimal treatment parameters with 0.63 composite desirability.

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“…The change in the temperature of the bacterial suspension caused by impulse voltage is an important factor for determining the effectiveness of sterilization rate [ 25 , 26 ]. If the pores created in the cell membrane by the pulsed electric field are larger than a certain size, the intracellular fluid will flow out and the bacteria will die.…”

Section: Discussionmentioning

confidence: 99%

“…The state of the phospholipids that make up the cell membrane is temperature dependent. Furthermore, a higher temperature is associated with a weaker lipid aggregation state; consequently, the sterilization treatment becomes more effective [ 25 , 26 ]. Heat is reported to be a factor that inhibits the repair of pores in the cell membrane, which may further enhance the sterilizing effect produced by impulse voltage [ 27 , 28 ].…”

Section: Discussionmentioning

confidence: 99%

Vancomycin-Resistant Enterococcus faecium Sterilization and Conductivity Change by Impulse Voltage

2023

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Owing to the increased use of antibiotics, drug-resistant strains, including those that are resistant to the antibiotic vancomycin, have emerged, which has become a major problem. In Japan, sewage treatments consist of sterilization with chlorine; however, this may not be sufficient to inactivate these bacteria. In this study, impulse voltage was employed instead of chlorine to inactivate drug-resistant bacteria. The results showed that sterilization above 105 CFU/mL is possible with longer application times of applied voltages above 4.5 kV. The effectiveness of impulse-voltage-mediated sterilization increased as the temperature of the bacterial suspension increased. The number of bacteria sterilized via impulse voltage was correlated with conductivity when the number of bacteria sterilized by impulse voltage exceeded 105 CFU/mL. The sterilization rate achieved by the use of impulse voltage could be estimated immediately by measuring the electrical conductivity and without the need for using the culture method.

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Liquid sterilization using intense electrical pulses combined with thermal post-treatment

Cited by 7 publications

References 12 publications

Low‐Temperature Pasteurization of Liquid Whole Egg using Intense Pulsed Electric Fields

Low‐Temperature Pasteurization of Liquid Whole Egg using Intense Pulsed Electric Fields

Processing and preservation of apple juice by pulsed electric fields combined with cinnamon essential oils: Exploring the effect of synergism

Vancomycin-Resistant Enterococcus faecium Sterilization and Conductivity Change by Impulse Voltage

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