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Development of bacterial spore pouches as a tool to evaluate the sterilization efficiency: A case study with microwave sterilization using Clostridium sporogenes and Geobacillus stearothermophilue

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posted on 2023-05-03, 17:45 authored by Aswathi Soni, Jeremy Smith, Richard Archer, Amanda Gardner, Kris Tong, Gale BrightwellGale Brightwell
In this study, novel spore pouches were developed using mashed potato as a food model inoculated with either Geobacillus stearothermophilus or Clostridium sporogenes spores. These spore pouches were used to evaluate the sterilization efficiency of Coaxially induced microwave pasteurization and sterilization (CiMPAS) as a case study. CiMPAS technology combines microwave energy (915 MHz) along with hot water immersion to sterilize food in polymeric packages. The spore pouches were placed at pre-determined specific locations, especially cold spots in each food tray before being processed using two regimes (R-121 and R-65), which consisted of 121 °C and 65 °C at 12 and 22 kW, respectively, followed by recovery and enumeration of the surviving spores. To identify cold spots or the location for inoculation, mashed potato was spiked with Maillard precursors and processed through CiMPAS, followed by measurement of lightness values (*L-values). Inactivation equivalent to of 1–2 Log CFU/g and >6 Log CFU/g for Geobacillus stearothermophilus and Clostridium sporogenes spores, respectively was obtained on the cold spots using R-121, which comprised of a total processing time of 64.2 min. Whereas, inactivation of <1 and 2–3 Log CFU/g for G. stearothermophilus and C. sporogenes spores, respectively on the cold spots was obtained using R-65 (total processing time of 68.3 min), whereas inactivation of 1–3 Log CFU/g of C. sporogenes spores was obtained on the sides of the tray. The results were reproducible across three processing replicates for each regime and inactivation at the specific locations were clearly distinguishable. The study indicated a strong potential to use spore pouches as a tool for validation studies of microwave-induced sterilization.

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© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

Language

  • English

Does this contain Māori information or data?

  • No

Publisher

MDPI

Journal title

Foods

ISSN

2304-8158

Citation

Soni, A., Smith, J., Archer, R., Gardner, A., Tong, K., & Brightwell, G. (2020). Development of bacterial spore pouches as a tool to evaluate the sterilization efficiency: A case study with microwave sterilization using Clostridium sporogenes and Geobacillus stearothermophilue. Foods, 9(10), 1342. doi:10.3390/foods9101342

Report number

FBP 90264

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