Apparatus for the simultaneous processing of mesophilic spores by heat-only and by high pressure and heat in a high pressure vessel to investigate synergistic spore inactivation. (February 2015)

• Record Type: Journal Article
• Authors: Olivier, S.A.; Smith, R.; Bull, M.K.; Chapman, B.; Knoerzer, K.
• Is Part Of: Innovative food science & emerging technologies. Volume 27(2015)
• Page Start: 35
• Page End: 40
• Publication Date: 2015-02
• Subjects: High pressure thermal processing -- Spore inactivation -- Synergy -- Clostridium sporogenes -- Bacillus amyloliquefaciens; Food -- Biotechnology -- Periodicals; Food industry and trade -- Technological innovations -- Periodicals; Aliments -- Biotechnologie -- Périodiques; Food -- Biotechnology; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.ifset.2014.12.003
• Languages: English
• ISSNs: 1466-8564

Abstract

Abstract: We sought to develop a paired sample container system that permits simultaneous processing of two samples in the same high pressure vessel, one pressurized and one protected by a pressure-resistant shell (heat-only), and subsequently compared the effect of pressure (600 MPa) on the inactivation of spores of Bacillus amyloliquefaciens and Clostridium sporogenes at high temperature. Reducing the compression rate to 200 MPa/min saw near-identical thermal profiles ( R 2 0.990) delivered to paired samples, thereby facilitating a means to directly attribute increases in inactivation in pressurised samples to the synergistic effect of pressure and heat. At 115 °C (3.5 min hold time), inactivation of B. amyloliquefaciens spores was around 7 log10 cfu/mL greater with pressure while the high pressure thermal (HPT) inactivation of C. sporogenes spores was approximately 2 log10 cfu/mL more than by heat alone after 1–2 min at 100 °C. Using this system we have demonstrated unequivocally that high pressure acts synergistically with heat to inactivate spores of B. amyloliquefaciens and C. sporogenes . Industrial relevance : To facilitate commercialization of HPT processing for low-acid foods, a significant improvement in spore inactivation by HPT compared to traditional thermal processing, or HPT synergy, needs to be demonstrated. The development of a system that permits unequivocal assessment of the synergistic effect of pressure and heat on spore inactivation is an important tool to assist validating such processes. Highlights: Specialized pressure-resistant sample containers were developed. Spore samples were processed simultaneously in a high pressure vessel, ± pressure. HPT synergistically inactivates spores of B. amyloliquefaciens and C. sporogenes .