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Fate of Listeria monocytogenes in Ready-to-Eat Refrigerated Dips Treated with High Pressure Processing

Joelle K Salazar1, Vidya Natarajan1, Diana Stewart1

  • 11 U.S. Food and Drug Administration, Division of Food Processing Science, Illinois Institute of Technology, 6502 South Archer Road, Bedford Park, Illinois 60501, USA.

Journal of Food Protection
|July 17, 2019
PubMed

Insights

High pressure processing (HPP) effectively reduces Listeria monocytogenes in hummus, guacamole, and baba ghanoush. However, HPP showed limited efficacy for inactivating this pathogen in tahini and pesto.

Area of Science:

  • Food Science
  • Microbiology
  • Food Safety

Background:

  • Ready-to-eat (RTE) food products, including dips, are susceptible to Listeria monocytogenes contamination, leading to outbreaks and recalls.
  • High pressure processing (HPP) is a nonthermal technology used for microbial reduction in RTE foods, but its effectiveness in various dips is not fully understood.

Purpose of the Study:

  • To evaluate the efficacy of HPP in reducing Listeria monocytogenes levels in different RTE dips.
  • To determine the D-values for Listeria monocytogenes inactivation in laboratory-prepared hummus, tahini, baba ghanoush, guacamole, and pesto.

Main Methods:

  • Laboratory-prepared dips (hummus, tahini, baba ghanoush, guacamole, pesto) were treated with HPP at 350 MPa for up to 240 seconds.
  • Further treatments were conducted at 600 MPa for up to 600 seconds for dips showing no significant reduction.
  • Listeria monocytogenes inactivation and D-values were determined.

Main Results:

  • HPP demonstrated significant Listeria monocytogenes reduction in hummus (D-value: 105.3 s), guacamole (D-value: 71.3 s), and baba ghanoush (D-value: 34.0 s) at 350 MPa.
  • No significant reduction in Listeria monocytogenes was observed in tahini or pesto, even after extended HPP treatment at 600 MPa.

Conclusions:

  • HPP is an effective method for reducing Listeria monocytogenes in certain RTE dips like hummus, guacamole, and baba ghanoush.
  • The efficacy of HPP varies significantly among different dip formulations, with tahini and pesto showing resistance to inactivation.
Keywords:
High pressure processingReady-to-eat foodsVegetable dips

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