Inactivation of Clostridium sporogenes PA 3679 spores by synergistic pressure-assisted thermal processing and antimicrobial compound combinations

• Published in: Food science & technology Vol. 209; p. 116785
• Main Authors: Astorga-Oquendo, Liz, Hu, Hetian, Yousef, Ahmed E., Balasubramaniam, V.M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2024
• Subjects: Antimicrobial compounds; Chitosan; Clostridium sporogenes spores; High-pressure processing; Pressure-assisted thermal processing; Chitosan; Antimicrobial compounds; Clostridium sporogenes spores; High-pressure processing; Pressure-assisted thermal processing
• ISSN: 0023-6438
• DOI: 10.1016/j.lwt.2024.116785

Pressure-assisted thermal processing (PATP) technology is an emerging sterilization method for food processing, ensuring microbiological safety with minimal heat damage. This study investigated the potential antimicrobial efficacy of 25 compounds, including enzymes, polysaccharides, cyclodextrins, cationic surfactants, polymers, and plant and fruit extracts, for the inactivation of Clostridium sporogenes PA 3679 spores during PATP. Experiments were conducted using a laboratory-scale, high-pressure processor. Spores suspended in pressure-stable buffer containing a potential antimicrobial agent were subjected to pressure (600 MPa) at 90 °C or 105 °C for a holding time of 3- and 6-min. Spore survivors were enumerated by spread-plating on Trypticase-Peptone-Glucose-Yeast Extract (TPGY) agar and incubated anaerobically at 32 °C for 5 days. PATP treatment at 600 MPa, 90 °C (3-min holding time) and 105 °C (3 or 6-min holding time) inactivated the spore by 1.5-, 3.8-, and 5.8-log spores/mL, respectively. Among all the antimicrobials tested, low- and high-molecular-weight chitosan enhanced PATP (600 MPa, 105 °C, 6-min holding time) inactivation of C. sporogenes spores by 7.9- and 6.9-log reductions, respectively. The treatment also decreased particle size and increased ζ potential of chitosan. Overall, combining PATP with chitosan is a promising synergistic strategy for spore elimination, possibly due to damage to the spore protective layers by PATP followed by chitosan electrostatic interaction. •Pressure-assisted thermal processing (PATP) destroys Clostridium sporogenes spores.•PATP at 600 MPa, 105 °C, 6 min yielded maximum spore reduction.•PATP and chitosan enhance lethality of Clostridium sporogenes spores by 7.9 log.•PATP reduces the particle size of low- and high-molecular-weight chitosan.•PATP raised the ζ-potential of chitosan by up to +11.4 mV.