Inactivation of Bacillus cereus spores using a combined treatment of UV-TiO2 photocatalysis and high hydrostatic pressure

Jeong Un Kim, Hafiz Muhammad Shahbaz, Jinho Cho, Hyunah Lee, Jiyong Park

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4 Citations (Scopus)


Bacillus cereus spores are resistant to high hydrostatic pressure (HHP) processing treatment. A combination of UV-TiO2 photocatalysis (UVTP for 10 min) and two cycles of 600 MPa HHP treatment for 10 min for the first cycle and 1 min for the second cycle (UVTP-2HHP) at ambient temperature was applied to inactivate B. cereus spores inoculated on a solidified agar matrix (SAM) used as a model matrix. Two cycles of HHP treatment were used as a strategy for induction of spore germination, followed by inactivation. UVTP and 2 cycles of HHP resulted in a 5.0-log CFU/cm2 spore reduction (initial spore count was 6.6 log CFU/cm2), including an approximate 0.8-log CFU/cm2 reduction due to a synergistic effect. The inactivation mechanism of UVTP pretreatment was related to lipid peroxidation of the spore membrane based on the level of malondialdehyde (MDA) making spores susceptible to the HHP treatment. Flow cytometry and transmission electron microscopic (TEM) analyses showed severe physiological alteration and structural damage to spores after the combined treatment. UVTP and 2 cycles of HHP showed potential for effective inactivation of B. cereus to ensure food safety from B. cereus spores on food products. Practical applications: Inactivation of bacterial spores remains a technical challenge for HHP and other interventions because spores are highly resistant to high pressure. Pretreatment with UVTP followed by two cycles of HHP resulted in reduction in B. cereus spores due to a synergistic effect. This hurdle technology of UVTP and HHP can help food industry in ensuring food safety against the Bacillus spores.

Original languageEnglish
Article number102676
JournalInnovative Food Science and Emerging Technologies
Publication statusPublished - 2021 Jun

Bibliographical note

Funding Information:
This research was partially supported by the Graduate School of Yonsei University, South Korea under Research Scholarship Grant in 2017.

Publisher Copyright:
© 2021 Elsevier Ltd

All Science Journal Classification (ASJC) codes

  • Food Science
  • Chemistry(all)
  • Industrial and Manufacturing Engineering


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