Inactivation of Escherichia coli, Saccharomyces cerevisiae, and Lactobacillus brevis in Low-fat Milk by Pulsed Electric Field Treatment: A Pilot-scale Study.

Korean journal for food science of animal resources · 2015 · Benefit · Low evidence

← Research stream

BenefitLow evidencePaper 2970

Study snapshot

PublicationKorean journal for food science of animal resources · 2015

Study typeother

Reported directionBenefit

Evidence ratingLow

Abstract

We investigated the effects of a pulsed electric field (PEF) treatment on microbial inactivation and the physical properties of low-fat milk. Milk inoculated with Escherichia coli, Saccharomyces cerevisiae, or Lactobacillus brevis was supplied to a pilot-scale PEF treatment system at a flow rate of 30 L/h. Pulses with an electric field strength of 10 kV/cm and a pulse width of 30 μs were applied to the milk with total pulse energies of 50-250 kJ/L achieved by varying the pulse frequency. The inactivation curves of the test microorganisms were biphasic with an initial lag phase (or shoulder) followed by a phase of rapid inactivation. PEF treatments with a total pulse energy of 200 kJ/L resulted in a 4.5-log reduction in E. coli, a 4.4-log reduction in L. brevis, and a 6.0-log reduction in S. cerevisiae. Total pulse energies of 200 and 250 kJ/L resulted in greater than 5-log reductions in microbial counts in stored PEF-treated milk, and the growth of surviving microorganisms was slow during storage for 15 d at 4℃. PEF treatment did not change milk physical properties such as pH, color, or particle-size distribution (p<0.05). These results indicate that a relatively low electric-field strength of 10 kV/cm can be used to pasteurize low-fat milk.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeother

Effect directionbenefit

PopulationNot supplied

Sample sizeNot supplied

Exposurepulse width 30 μs; storage 15 d at 4℃ (post-treatment observation)

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Low-fat milk inoculated with E. coli, S. cerevisiae, or L. brevis was treated with PEF at 10 kV/cm (30 μs pulses) with total pulse energies 50–250 kJ/L. At 200 kJ/L, reductions were 4.5-log (E. coli), 4.4-log (L. brevis), and 6.0-log (S. cerevisiae); 200–250 kJ/L produced >5-log reductions in stored treated milk and surviving microorganisms grew slowly over 15 days at 4℃. The authors report no change in milk pH, color, or particle-size distribution (p<0.05).

Outcomes measured

Microbial inactivation (log reductions) of Escherichia coli
Microbial inactivation (log reductions) of Saccharomyces cerevisiae
Microbial inactivation (log reductions) of Lactobacillus brevis
Milk physical properties (pH, color, particle-size distribution)
Microbial growth during storage (15 d at 4℃)

Limitations

Pilot-scale study
No sample size reported in abstract
Exposure parameters reported as electric field strength and pulse energy; no EMF frequency information provided
Statement about physical properties includes 'did not change' alongside 'p<0.05' as written in abstract, which is internally unclear

View raw extracted JSON

{
  "study_type": "other",
  "exposure": {
    "band": null,
    "source": "pulsed electric field (PEF) food processing system",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "pulse width 30 μs; storage 15 d at 4℃ (post-treatment observation)"
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "Microbial inactivation (log reductions) of Escherichia coli",
    "Microbial inactivation (log reductions) of Saccharomyces cerevisiae",
    "Microbial inactivation (log reductions) of Lactobacillus brevis",
    "Milk physical properties (pH, color, particle-size distribution)",
    "Microbial growth during storage (15 d at 4℃)"
  ],
  "main_findings": "Low-fat milk inoculated with E. coli, S. cerevisiae, or L. brevis was treated with PEF at 10 kV/cm (30 μs pulses) with total pulse energies 50–250 kJ/L. At 200 kJ/L, reductions were 4.5-log (E. coli), 4.4-log (L. brevis), and 6.0-log (S. cerevisiae); 200–250 kJ/L produced >5-log reductions in stored treated milk and surviving microorganisms grew slowly over 15 days at 4℃. The authors report no change in milk pH, color, or particle-size distribution (p<0.05).",
  "effect_direction": "benefit",
  "limitations": [
    "Pilot-scale study",
    "No sample size reported in abstract",
    "Exposure parameters reported as electric field strength and pulse energy; no EMF frequency information provided",
    "Statement about physical properties includes 'did not change' alongside 'p<0.05' as written in abstract, which is internally unclear"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "pulsed electric field",
    "PEF",
    "low-fat milk",
    "pasteurization",
    "microbial inactivation",
    "Escherichia coli",
    "Saccharomyces cerevisiae",
    "Lactobacillus brevis",
    "pilot-scale"
  ],
  "suggested_hubs": [
    {
      "slug": "engineering",
      "weight": 0.78,
      "reason": "Pilot-scale pulsed electric field processing parameters and performance."
    },
    {
      "slug": "food-processing",
      "weight": 0.72,
      "reason": "Application of PEF for milk pasteurization and quality outcomes."
    }
  ]
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.5851/kosfa.2015.35.6.800
PubMed: 26877640

Read the original paper →

Related papers

← Back to the Research Library