Searching for high pressure processing parameters for Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes reduction in Concord grape juice
ISSN: 0007-070X
Article publication date: 5 November 2019
Issue publication date: 6 January 2020
Abstract
Purpose
High pressure processing (HPP) has been widely used for high-acid (pH<4.6) juices. The purpose of this study was to investigate optimal parameters aimed at achieving 5-log reduction of the pathogens of reference in Concord grape juice (pH 3.39).
Design/methodology/approach
Grape juice was inoculated with five strain cocktails of Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes. In total, 11 trials were carried out based on a Central Composite Rotational Design (CCRD). The pressure (P), ranging from 319 to 531 MPa, and dwell time (t), from 35 to 205 s, were tested. The performance of the combinations (P × t) was evaluated by pathogen challenge microbiological assays.
Findings
E. coli O157:H7 was more resistant to HPP than S. enterica. L. monocytogenes did not grow in unprocessed juice (before HPP). Findings demonstrated that moderate pressures (~400 MPa) and short dwell times (~2 min) were effective in achieving a greater than 5-log reduction in the pathogens of reference.
Practical implications
Because the maintenance costs of equipment exponentially increase with pressure beyond 600 MPa, significant reductions in process pressure are highly desirable.
Originality/value
The results of this study can supplement the dearth of information on the applicability of high pressure as a Concord grape juice processing technology in terms of the pathogens inactivation. Furthermore, the use of a cocktail of five strains of pathogens inoculated in Concord grape juice to challenge different HPP parameters has not been reported.
Keywords
Acknowledgements
This research work was financially supported by the São Paulo Research Foundation/Brazil (Grant No. 2017/24172-6) and Cornell High Pressure Processing (HPP) Validation Center – Geneva/USA.
Citation
Petrus, R., Churey, J. and Worobo, R. (2020), "Searching for high pressure processing parameters for
Publisher
:Emerald Publishing Limited
Copyright © 2019, Emerald Publishing Limited